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1,886,443 | Taming the Evolving Beast: Understanding and Implementing API Versioning | In the ever-changing world of web development, APIs (Application Programming Interfaces) play a... | 0 | 2024-06-13T03:56:15 | https://dev.to/epakconsultant/taming-the-evolving-beast-understanding-and-implementing-api-versioning-1dhe | api | In the ever-changing world of web development, APIs (Application Programming Interfaces) play a crucial role in enabling communication between different applications. However, as APIs evolve and features are added or modified, a critical concept comes into play: API versioning.
## What is API Versioning?
API versioning is the practice of managing changes to an API in a way that ensures minimal disruption for existing users (clients) who rely on the API. Versioning allows you to introduce new features, modify existing ones, or even deprecate functionalities without breaking the applications that depend on the older versions.
[Demystifying Azure Costs: Setting Up a Cost Center Dashboard
](https://cloudbelievers.blogspot.com/2024/06/demystifying-azure-costs-setting-up.html)
## Why is API Versioning Important?
Imagine a popular web app that relies on a specific API version for core functionalities. Suddenly, the API provider releases a new version with significant changes. If the app isn't updated to adapt to the new version, it might malfunction or even break entirely, causing a frustrating user experience.
API versioning mitigates this risk by providing a controlled environment for updates. Existing clients can continue using the familiar version while developers can gradually migrate their applications to the newer, potentially improved version.
## Common API Versioning Strategies
Here are three popular approaches to API versioning:
1.URI Versioning: This strategy incorporates the version number directly into the API endpoint URL. For example, /v1/users might represent data access in version 1, while /v2/users could point to an updated version with additional functionalities. This is a straightforward approach, but managing multiple URLs can become cumbersome over time.
2.Query Parameter Versioning: Here, the version number is included as a query parameter in the API request URL. For example, /users?version=1 would access version 1, and /users?version=2 would access version 2. This approach offers more flexibility but can lead to cluttered URLs.
3.Header Versioning: This strategy transmits the version number within a custom header sent along with the API request. This keeps the URL clean and allows for easier server-side identification of the requested version. However, it requires additional configuration on the client-side.
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## Choosing the Right Versioning Strategy
The optimal versioning strategy depends on several factors, including the complexity of your API, the anticipated frequency of changes, and developer preference. URI versioning is a popular choice for its simplicity, while header versioning might be preferred for a cleaner URL structure.
Best Practices for API Versioning
• Clear Documentation: Provide comprehensive documentation for each API version, highlighting changes, deprecations, and migration guides.
• Backward Compatibility: Whenever possible, strive to maintain backward compatibility for key functionalities across versions.
• Deprecation Strategy: Clearly define a deprecation timeline for older versions to allow developers time to migrate.
• Version Negotiation: Consider implementing version negotiation to allow clients to specify their preferred version and gracefully handle unsupported versions.
## Conclusion
API versioning is an essential practice for ensuring the longevity and smooth evolution of APIs. By understanding different versioning strategies and best practices, you can create a robust and adaptable API that caters to both existing and future users. Remember, a well-versioned API fosters a healthy developer ecosystem and ultimately contributes to the success of your web application.
| epakconsultant |
1,886,433 | Unleashing the Power of ES6: Modernizing Your JavaScript Development | ES6, or ECMAScript 2015, marked a significant leap forward in JavaScript's capabilities. By embracing... | 0 | 2024-06-13T03:50:55 | https://dev.to/epakconsultant/unleashing-the-power-of-es6-modernizing-your-javascript-development-54k9 | javascript | ES6, or ECMAScript 2015, marked a significant leap forward in JavaScript's capabilities. By embracing its features, you can write cleaner, more maintainable, and expressive code. Here's a dive into how to effectively utilize ES6 in your development workflow:
1. Embrace Const and Let for Variable Declarations
Ditch the traditional var keyword and adopt const and let for variable declarations. const creates immutable variables, ideal for scenarios where the value shouldn't change. let creates block-scoped variables, preventing unintended variable conflicts within loops and conditional statements. This promotes code clarity and reduces the risk of errors.
[A Beginners Guide to Integrating ChatGPT into Your Chatbot: Enhancing Your Chatbots Capabilities](https://www.amazon.com/dp/B0CNZ1T4WX)
Example:
JavaScript
`// Before ES6 (var can cause scope issues)
for (var i = 0; i < 10; i++) {
console.log(i); // Logs 0 to 9
}
console.log(i); // Still accessible outside the loop (unexpected behavior)
// After ES6 (let for block-scoped variables)
for (let i = 0; i < 10; i++) {
console.log(i); // Logs 0 to 9
}
console.log(i); // Reference error (i is not accessible)`
2. Leverage Template Literals for Readable Strings
Template literals (introduced with backticks) allow for cleaner string manipulation and interpolation. Embed variables and expressions directly within strings, eliminating the need for cumbersome concatenation.
Example:
JavaScript
`// Before ES6 (string concatenation)
const name = "Alice";
const greeting = "Hello, " + name + "!";
// After ES6 (template literals)
const name = "Alice";
const greeting = `Hello, ${name}!`;`
3. Simplify Arrow Functions for Concise Syntax
Arrow functions provide a concise way to define functions. They are particularly useful for short, single-expression functions and event handlers.
Example:
JavaScript
`// Before ES6 (traditional function declaration)
function add(x, y) {
return x + y;
}
// After ES6 (arrow function)
const add = (x, y) => x + y;`
[Demystifying Cybersecurity: Understanding Principles and Technologies
](https://dataprophet.blogspot.com/2024/06/demystifying-cybersecurity.html)
4. Destructuring for Efficient Object/Array Handling
Destructuring allows you to unpack values from objects or arrays into separate variables. This simplifies complex data access and enhances code readability.
Example:
JavaScript
`// Before ES6 (traditional object access)
const person = { name: "Bob", age: 30 };
const name = person.name;
const age = person.age;
// After ES6 (destructuring)
const person = { name: "Bob", age: 30 };
const { name, age } = person;`
5. Utilize Classes for Object-Oriented Programming
ES6 introduces a more robust class syntax for object-oriented programming. Define classes with constructors, methods, and inheritance to create reusable blueprints for objects.
Example:
JavaScript
`// Before ES6 (object literal approach)
const car = {
brand: "Honda",
accelerate() {
console.log("Car is accelerating!");
}
};
// After ES6 (class syntax)
class Car {
constructor(brand) {
this.brand = brand;
}
accelerate() {
console.log("Car is accelerating!");
}
}
const honda = new Car("Honda");
honda.accelerate();
`
6. Explore Modules for Code Organization
ES6 introduces a module system for better code organization. Break down your code into reusable modules, each containing functions, variables, and classes. Use import and export statements to manage dependencies between modules.
Example:
// greet.js (exporting a function) export function greet(name) { console.log(Hello, ${name}!); }
// app.js (importing the function) import { greet } from './greet.js';
greet("World");
Remember:
• Consider browser compatibility when targeting older browsers. Tools like Babel can transpile your ES6 code to a compatible format.
• Start with a gradual adoption of ES6 features to avoid overwhelming your codebase.
• Utilize online resources and tutorials to deepen your understanding of these powerful features.
By effectively utilizing ES6, you can write cleaner, more maintainable, and modern JavaScript code, ultimately enhancing your development workflow and creating robust web applications.
| epakconsultant |
1,886,423 | Unpacking the Byte: The Tiny Titan of Data! | This is a submission for DEV Computer Science Challenge v24.06.12: One Byte Explainer. ... | 0 | 2024-06-13T03:44:47 | https://dev.to/wanjala/byte-the-data-building-block-16ni | devchallenge, cschallenge, computerscience, beginners | _This is a submission for DEV Computer Science Challenge v24.06.12: One Byte Explainer._
## Explainer
<!-- Explain a computer science concept in 256 characters or less. -->
Byte (B): A unit of digital information in computing, typically consisting of 8 bits. The smallest addressable unit of memory in most systems. Bytes store individual characters (letters, numbers, symbols) or basic instructions.
## Additional Context
<!-- Please share any additional context you think the judges should take into consideration as it relates to your One Byte Explainer. -->
<!-- Team Submissions: Please pick one member to publish the submission and credit teammates by listing their DEV usernames directly in the body of the post. -->
<!-- Don't forget to add a cover image to your post (if you want). -->
<!-- Thanks for participating! --> | wanjala |
1,886,419 | Cloud and AI: The One-Two Punch Reshaping Media | A Transformation Beyond Belief Alright, folks, strap yourselves in 'cause the media industry is... | 0 | 2024-06-13T03:36:08 | https://dev.to/kevintse756/cloud-and-ai-the-one-two-punch-reshaping-media-3ck3 |
A Transformation Beyond Belief
Alright, folks, strap yourselves in 'cause the media industry is going through a transformation so mind-blowing, it'll make your jaw drop. And it's all thanks to two tech titans – cloud computing and Artificial Intelligence (AI). These game-changers are turning traditional approaches on their heads, dragging us into an era that was once the stuff of sci-fi movies.
The Ultimate Power Couple
When you combine the scalability and flexibility of the cloud with the intelligence and efficiency of AI, you get this insane synergy that amplifies the capabilities of each technology. It's like getting a two-for-one deal, where the cloud provides the infrastructure muscle, and AI brings the brainpower to the table. Imagine being able to process massive data sets with advanced analytics, leading to insights that were previously out of reach.
Supercharging Content Creation
AI-powered tools like automatic video editing and scriptwriting are putting the creative process on steroids, allowing content creators to churn out work at lightning speed compared to the old-school methods. Take Adobe Creative Cloud, for instance – it leverages AI to connect creators with tools that streamline and enhance the creative workflow. And with cloud-based collaboration, team members can work together in real-time, no matter where they're located.
Making Media Management and Distribution a Breeze
The cloud has completely overhauled how we handle media asset management, offering scalable storage solutions and global content access. AI steps in to automate content curation and metadata generation processes, making sorting and retrieving media a piece of cake. Companies like AWS Elemental have harnessed the cloud to optimize media delivery, ensuring content reaches wider audiences with optimal network performance.
Taking Viewer Engagement to Unprecedented Heights
By combining the power of AI and the cloud, media companies can take viewer engagement to unprecedented heights. Personalized content recommendations based on AI algorithms mine viewer preferences, ensuring they get exactly what they want, when they want it. Cloud-based streaming services like Netflix use these technologies to deliver a seamless experience, continuously analyzing viewer behavior to improve the user experience in real-time.
Pioneers Blazing the Trail
Companies like [TVU Networks](https://www.tvunetworks.com/) are leading the charge, leveraging cloud and AI to innovate in areas like live streaming and remote production. This allows broadcasters to produce high-quality content with greater flexibility and lower costs. [IBM Watson Media ](https://www.ibm.com/products/video-streaming)uses AI to automate tasks like video content management, highlight clipping, and captioning, revolutionizing content management. And let's not forget [Adobe](https://www.adobe.com/), which has transformed the creative process across all media forms by integrating AI and cloud technologies, automating mundane tasks and enhancing creativity.
Challenges and Future Prospects
Of course, this integration ain't all rainbows and unicorns. Data security, implementation costs, and integration complexities are all hurdles that need to be tackled. But the future looks promising, with advancements in AI and cloud infrastructure on the horizon. Media companies need to stay ahead of the curve, continuously innovating to leverage these technologies effectively.
The Bottom Line
The convergence of cloud computing and AI in the media sector ain't just a passing fad – it's an organic force that's redefining the industry's very essence. As audience expectations evolve rapidly, this integration isn't just a nice-to-have; it's a necessity for survival. Only by embracing these technologies can organizations unlock unprecedented levels of innovation and efficiency. So, media professionals and companies, it's time to dive in, experiment, and share your experiences with these truly transformational technologies. After all, crafting new technologies is meaningless without understanding the needs of the end-users. Let's start a dialogue in the comments section below and shape the future of media together. | kevintse756 | |
1,886,417 | Creating AI Applications with Pixie: A Step-by-Step Guide | Whether you're creative enthusiasts or seasoned developers, Pixie simplifies the creation of... | 0 | 2024-06-13T03:34:52 | https://dev.to/gptconsole/creating-ai-applications-with-pixie-a-step-by-step-guide-1bfn |
Whether you're creative enthusiasts or seasoned developers, Pixie simplifies the creation of intricate projects, including AI-driven applications such as text generation, image generation, and text-to-speech utilities. Let's walk you through the process:
**Step 1:**Signup and login gptconsole
**Step 2:**Prompt for Text Generation Application
"_Pixie, create a text generation web application with an intuitive user interface and API endpoints for dynamic content creation._"
**Step 3:**Designing Your Dashboard
Once Pixie receives the prompt, the AI gets to work, designing a dashboard grounded in the best UX/UI practices. You can expect a slick, easy-to-navigate dashboard where users can interact with the text generation features of your web application.
**Step 4:** Embedding Advanced Features
The strength of Pixie lies in its ability to update generated AI applications. For implementing an image generation feature, your prompt could be:
"Pixie, integrate an image generation feature within the application that uses a neural network to convert text descriptions into visuals."
**Conclusion**
Pixie embodies the pinnacle of AI-augmented web application development, providing developers with an unparalleled ease of use. By entrusting repetitive and complex coding tasks to Pixie, your focus can shift to the creative and strategic aspects of development. This guide is a mere glimpse into the spectrum of possibilities that Pixie unlocks.
Embrace the future of web development with Pixie—where your next advanced AI web application is just a prompt away
| vincivinni | |
1,886,416 | Node.js Timeouts and Memory Leaks | Introduction Issue Overview: The way Node.js handles timeouts can lead to significant... | 0 | 2024-06-13T03:34:16 | https://dev.to/srijan_karki/nodejs-timeouts-and-memory-leaks-3l64 | javascript, webdev, node |
#### Introduction
- **Issue Overview**: The way Node.js handles timeouts can lead to significant memory leaks.
- **Background**: The `setTimeout` API is commonly used in both browsers and Node.js. While it works similarly, Node.js returns a more complex object, which can cause problems.
#### Basic Timeout API
- **In Browsers**:
- *Token*: A simple number representing the timeout ID.
```javascript
const token = setTimeout(() => {}, 100);
clearTimeout(token);
```
- **In Node.js**:
- *Token*: An object with multiple properties and references.
```javascript
const token = setTimeout(() => {});
console.log(token);
```
#### Example of Timeout Object in Node.js
```javascript
Timeout {
_idleTimeout: 1,
_idlePrev: [TimersList],
_idleNext: [TimersList],
_idleStart: 4312,
_onTimeout: [Function (anonymous)],
_timerArgs: undefined,
_repeat: null,
_destroyed: false,
[Symbol(refed)]: true,
[Symbol(kHasPrimitive)]: false,
[Symbol(asyncId)]: 78,
[Symbol(triggerId)]: 6
}
```
- **Properties**: Includes metadata about the timeout, references to other objects, and functions.
- **Issue**: These references prevent the timeout object from being garbage collected even after it’s cleared or completed.
#### Class Example Leading to Memory Leak
```javascript
class MyThing {
constructor() {
this.timeout = setTimeout(() => { /*...*/ }, INTERVAL);
}
clearTimeout() {
clearTimeout(this.timeout);
}
}
```
- **Persistent Reference**: The `Timeout` object persists in memory because it is an object with references, not a simple number.
#### Impact of AsyncLocalStorage
- **AsyncLocalStorage**: A new API that attaches additional state to timeouts, promises, and other asynchronous operations.
- **Example**:
```javascript
const { AsyncLocalStorage } = require('node:async_hooks');
const als = new AsyncLocalStorage();
let t;
als.run([...Array(10000)], () => {
t = setTimeout(() => {
const theArray = als.getStore();
}, 100);
});
```
- **Result**: The timeout object now holds a reference to a large array via a custom Symbol, which persists even after the timeout is cleared or completes.
```javascript
Timeout {
[Symbol(kResourceStore)]: [Array] // reference to that large array is held here
}
```
#### Suggested Fix: Using Primitive IDs
- **Approach**: Convert the `Timeout` object to a number to avoid holding references.
```javascript
class MyThing {
constructor() {
this.timeout = +setTimeout(() => { /*...*/ }, INTERVAL);
}
clearTimeout() {
clearTimeout(this.timeout);
}
}
```
- **Current Problem**: Due to a bug in Node.js, this approach currently causes an unrecoverable memory leak.
#### Workaround: Aggressive Nullification
- **Strategy**: Manually clear the timeout reference to help garbage collection.
```javascript
class MyThing {
constructor() {
this.timeout = setTimeout(() => {
this.timeout = null;
// Additional logic
}, INTERVAL);
}
clearTimeout() {
if (this.timeout) {
clearTimeout(this.timeout);
this.timeout = null;
}
}
}
```
#### Broader Implications
- **Widespread Issue**: Many Node.js applications use timeouts and intervals, increasing the risk of memory leaks.
- **Hot Code Reloading**: Long-lasting or recurring timeouts can exacerbate the problem.
- **Next.js Workaround**: Patches `setTimeout` and `setInterval` to clear intervals periodically, but can still encounter the Node.js bug.
#### Long-Term Considerations
- **API Improvements**: Node.js could return a lightweight proxy object instead of the full `Timeout` object, which would be easier to manage and less prone to leaks.
- **AsyncLocalStorage Management**: Providing APIs to prevent unnecessary state propagation can help reduce memory leaks.
### Conclusion
- **Memory Management**: Developers need to carefully manage timeouts and their references to avoid memory leaks.
- **Awaiting Node.js Fix**: A permanent fix for the underlying Node.js bug is crucial for effective memory management.
Understanding these nuances and adopting best practices can help mitigate memory leaks in Node.js applications, ensuring better performance and stability. | srijan_karki |
1,886,415 | Node.js Timeouts and Memory Leaks | - Memory Leak Issue: Node.js timeouts can easily create memory leaks. Timeout API: Unlike... | 0 | 2024-06-13T03:34:15 | https://dev.to/srijan_karki/nodejs-timeouts-and-memory-leaks-5g1p | webdev, javascript, node |
- **Memory Leak Issue**: Node.js timeouts can easily create memory leaks.
- **Timeout API**: Unlike browsers, where `setTimeout` returns a number, Node.js returns a `Timeout` object.
- **Timeout Object**: This object includes several properties and can retain references, causing memory issues.
### Example of Memory Leak
```javascript
class MyThing {
constructor() {
this.timeout = setTimeout(() => { ... }, INTERVAL);
}
clearTimeout() {
clearTimeout(this.timeout);
}
}
```
- **Problem**: The `Timeout` object remains even after `clearTimeout` or timeout completion, holding references that prevent garbage collection.
### Impact of AsyncLocalStorage
- **AsyncLocalStorage**: Attaches state to timeouts, making leaks worse.
- **Example**:
```javascript
const { AsyncLocalStorage } = require('node:async_hooks');
const als = new AsyncLocalStorage();
let t;
als.run([...Array(10000)], () => {
t = setTimeout(() => {
const theArray = als.getStore();
}, 100);
});
```
- **Result**: Timeout holds a reference to a large array, exacerbating the memory issue.
### Suggested Fix
- **Use ID Instead of Object**:
```javascript
class MyThing {
constructor() {
this.timeout = +setTimeout(() => { ... }, INTERVAL);
}
clearTimeout() {
clearTimeout(this.timeout);
}
}
```
- **Problem**: Current Node.js bug makes this approach cause an unrecoverable memory leak.
### Workaround
- **Aggressive Nullification**:
```javascript
class MyThing {
constructor() {
this.timeout = setTimeout(() => {
this.timeout = null;
}, INTERVAL);
}
clearTimeout() {
if (this.timeout) {
clearTimeout(this.timeout);
this.timeout = null;
}
}
}
```
### Broader Implications
- **Widespread Use**: Many applications use timeouts and intervals, leading to potential memory issues.
- **Next.js**: Patches `setTimeout` and `setInterval` to clear intervals, though it can encounter related bugs.
### Long-Term Considerations
- **Better API Design**: Node.js could improve by returning a lightweight proxy object instead of the full `Timeout` object.
- **AsyncLocalStorage Management**: Need for APIs to prevent propagation of unnecessary state to avoid leaks.
### Conclusion
- **Memory Management**: Developers need to be cautious with timeouts and AsyncLocalStorage to avoid memory leaks.
- **Awaiting Fix**: A fix for the underlying Node.js bug is crucial for long-term resolution. | srijan_karki |
1,886,412 | Weaving the Web of Conversation: Implementing Chat Functionality in Your Web App | In today's fast-paced online world, real-time communication is key. Integrating chat functionality... | 0 | 2024-06-13T03:31:38 | https://dev.to/epakconsultant/weaving-the-web-of-conversation-implementing-chat-functionality-in-your-web-app-l0h | chat | In today's fast-paced online world, real-time communication is key. Integrating chat functionality into your web app can foster user engagement, build a strong community, and provide a valuable support channel. But where do you begin? Here's a roadmap to guide you through implementing chat in your web app:
1. Define Your Needs
• Purpose: Identify the primary goal of your chat. Is it for customer support, peer-to-peer communication, or facilitating group discussions?
• Target Audience: Understand your user base. How will chat functionality benefit them? Will it require one-on-one interactions or larger group chats?
•Features: Decide on the essential features for your chat. This could include private messaging, group chats, file sharing, and message history.
[Mastering AWS CentOS & Linux Instances: The Foundation of Scalable and Reliable Cloud Computing](https://cloud-computing-for-beginner.blogspot.com/2024/06/mastering-aws-centos-linux-instances.html)
2. Choosing Your Approach
• Building from Scratch: This offers maximum control over customization but requires significant development resources and expertise in real-time communication protocols like WebSockets or Server-Sent Events (SSE).
[Mastering OWL 2 Web Ontology Language: From Foundations to Practical Applications](https://www.amazon.com/dp/B0CT93LVJV)
• Third-party Chat SDKs: Software Development Kits (SDKs) from established providers like PubNub or Pusher offer pre-built functionalities, simplifying development and reducing time to market.
• Chat as a Service (CaaS): CaaS solutions like Firebase or Amazon Simple Notification Service (SNS) handle the server-side infrastructure, allowing you to focus on building the chat user interface (UI) within your app.
3. Backend Development
• User Management: Create a system for user authentication and authorization. This ensures only authorized users can access the chat and controls access levels within group chats.
• Real-time Communication: Implement the chosen real-time communication protocol to enable instant message delivery and updates. WebSockets are a popular choice for their low latency and bi-directional communication.
• Data Storage: Determine how you'll store chat messages. Options include real-time databases like Firebase Realtime Database or traditional relational databases like MySQL.
• Scalability: Design your backend with scalability in mind to accommodate a growing user base and increased chat traffic.
4. User Interface (UI) Design
• Chat Window: Create a user-friendly chat window that displays messages, allows for easy typing, and provides access to chat features.
• Intuitive Interface: Make the UI clean and uncluttered, with clear icons and functionalities readily identifiable.
• Notifications: Implement a notification system to alert users of new messages, mentions, or private messages.
• Accessibility: Ensure your chat UI is accessible to users with disabilities, adhering to WCAG (Web Content Accessibility Guidelines).
5. Security Considerations
• Data Encryption: Encrypt all chat messages in transit and at rest to protect sensitive information.
• User Authentication: Implement robust user authentication to prevent unauthorized access to chat functionalities.
• Content Moderation: Consider establishing content moderation policies and tools to manage inappropriate content and maintain a safe chat environment.
6. Testing and Deployment
• Rigorous Testing: Thoroughly test all aspects of the chat functionality, including message delivery, group chat behavior, and user authentication.
• Phased Rollout: Consider a phased rollout to a limited user group for initial feedback and bug identification before a wider launch.
Bonus Tip: Integrate chat functionality seamlessly with your overall web app design to ensure a cohesive user experience.
By following these steps and carefully considering your specific needs, you can successfully implement chat functionality into your web app. This will not only enhance user engagement but also foster a sense of community and provide valuable communication channels for your users. Remember, a well-designed chat can be a powerful tool to transform your web app from a static platform to a vibrant online hub.
| epakconsultant |
1,886,411 | Power Up Your Web App: Implementing Subscription Management | Subscription-based models are booming, offering a steady revenue stream for businesses and flexible... | 0 | 2024-06-13T03:25:22 | https://dev.to/epakconsultant/power-up-your-web-app-implementing-subscription-management-3gpa | webdev, development | Subscription-based models are booming, offering a steady revenue stream for businesses and flexible access for users. If you're considering this approach for your web app, integrating a smooth subscription management system is crucial. Here's a breakdown of the key steps involved:
[Scripting and Coding Skills: PowerShell, and Python for automating tasks and managing cloud](https://nocodeappdeveloper.blogspot.com/2024/06/scripting-and-coding-skills-powershell.html)
1. Planning and Design
• Define Your Goals: Identify what you want to achieve with subscriptions. Is it tiered access to features, exclusive content, or recurring service delivery?
• Know Your Users: Understand their needs and preferences. How will subscriptions enhance their experience?
• Craft Your Tiers: Design subscription plans with clear benefits and pricing structures. Offer a free tier to attract users and premium tiers with increasing value.
2. Backend Development
• User Management: Create a secure system for user accounts, storing information like subscription status and billing details.
• Payment Gateway Integration: Partner with a reputable payment gateway like Stripe or PayPal to handle secure transactions.
• Subscription Logic: Develop the backend functionality to manage subscriptions. This includes processing payments, tracking subscription status (active, cancelled, expiring), and updating user access levels based on their plan.
[Unlock Your Cybersecurity Potential: The Essential Guide to Acing the CISSP Exam](https://www.amazon.com/dp/B0D42PRZD8)
• Recurring Billing: Implement automated recurring billing to ensure uninterrupted service for subscribed users. Consider offering flexible payment options like monthly or annual billing cycles.
• Webhooks: Set up webhooks to receive real-time notifications from your payment gateway about subscription changes (cancellations, chargebacks, etc.). This allows you to update user accounts and app access accordingly.
3. User Interface (UI) Design
• Subscription Page: Design a dedicated page for users to subscribe, manage their plans, and view billing history.
• Clear Presentation: Clearly display subscription tiers, their features, and pricing. Use concise language and visuals to simplify understanding.
• Easy Onboarding: Streamline the signup process for new subscribers. Integrate payment methods during the initial subscription flow.
• User-friendly Management: Allow users to easily view their current plan, upgrade or downgrade, and manage payment methods. Emphasize transparent cancellation options.
4. Security Considerations
• Data Encryption: Implement robust security measures to protect sensitive user data like payment information.
• Regular Updates: Ensure your web app stays up-to-date with the latest security patches to mitigate vulnerabilities.
• Compliance: Adhere to industry standards like PCI-DSS for secure credit card transactions.
5. Testing and Deployment
• Thorough Testing: Rigorously test all functionalities of your subscription management system, including signups, payments, cancellation flows, and user access control.
• Phased Rollout: Consider a phased rollout to identify and address any issues before a full launch.
Bonus Tip: Provide excellent customer support to address user queries regarding subscriptions and billing.
By following these steps, you can effectively implement subscription management into your web app, creating a sustainable revenue model and a user-friendly experience that keeps your customers engaged. Remember, a well-designed subscription system can be a powerful tool for growth and success.
| epakconsultant |
1,886,377 | Looking into GenAI | GenAI is a framework implementing design principles with the help of artificial intelligence. I... | 0 | 2024-06-13T02:29:41 | https://dev.to/christopherchhim/looking-into-genai-46g7 | webdev, ai, ux | GenAI is a framework implementing design principles with the help of artificial intelligence. I decided to look into GenAI because it helps me learn as to how we can design interfaces with the help of AI. AI is a tool meant to help and assist our abilities, but not replace them. GenAI has 6 key dimensions: discovery, assisting, exploration, refinement, trust, and mastery. Not all dimensions will be used for generating design and all function independently from one another.
1. Discovery
GenAI helps users recognize when AI is being in use or not, therefore providing users the freedom to do what they want while providing assistance if they so choose.
2. Assisting
GenAI provides suggestions and templates to allow users to creatively explore while having assistance at their disposal. GenerativeAI shifts from structured guidance to autonomous discovery.
3. Exploration
Gen AI allows users to explore their creativity by blending with AI whenever desired. GenAI emphasizes the fluidity of interaction between users and GenAI by facilitating a dialogue that can distill complex data into actionable insights or creative outputs. GenAI can be used as a tool for users to take creative leaps and make innovative solutions to their discoveries.
4. Refinement
GenAI refines its platforms by providing intuitive customization options that align the AI’s output with their specific needs and vision. GenAI is capable of replicating an individual's tone, voice, and style. These tools can help a user tune their product however they see fit.
5. Trust
GenAI establishes trust amongst users using its platform and services. This is done so that users know that they have an intelligent assistant whenever they need it. Users will have the knowledge to navigate their GenAI experience with confidence. GenAI permits its users to ignore and undo suggestive actions allowing users to confidently use its services thanks to its collaborative features. These features prevent the AI from overwhelming its users.
6. Mastery
GenAI's features are mainly exploited by AI engineers because of its complexity. It aims to simplify tedious code but it is still hard to navigate nonetheless. In the Mastery dimension, a deep understanding of GenAI allows room for improvement, pushing designers to create with both precision and conscience. GenAI can collaborate with users and allow them to make changes to its services. This would allow humans to co-design with machines to shape a user's experience in the tech world.
This post was inspired from:
Koc, V. (2024, April 4) The GenAI Compass: a UX framework to design generative AI experiences
Retrieved from: [https://uxdesign.cc/the-genai-compass-a-ux-framework-to-design-generative-ai-experiences-49a7d797c114#3b1b]
| christopherchhim |
1,886,409 | Python Version Commodity Futures Moving Average Strategy | It is completely transplanted from the "CTP Commodity Futures Variety Moving Average Strategy". Since... | 0 | 2024-06-13T03:24:41 | https://dev.to/fmzquant/python-version-commodity-futures-moving-average-strategy-5aa0 | strategy, python, cryptocurrency, fmzquant | It is completely transplanted from the "CTP Commodity Futures Variety Moving Average Strategy". Since the Python version of the commodity futures strategy does not yet have a multi-variety strategy, the JavaScript version of the "CTP Commodity Futures Multi-Variable Moving Average Strategy" was ported. Providing some design ideas and examples of Python commodity futures multi-variety strategy. Regardless of the JavaScript version or the Python version, the strategy architecture design originates from the Commodity futures multi-varieties turtle strategy.
As the simplest strategy, the moving average strategy is very easy to learn, because the moving average strategy does not have any advanced algorithms and complex logic. The ideas are clear and easy, allowing beginners to focus more on the study of strategy design, and even remove the coding related part, leaving a multi-variety strategy framework that can be easily expanded into ATR, MACD, BOLL and other indicator strategies.
Articles related to the JavaScript version: https://www.fmz.com/bbs-topic/5235.
## Strategy source code
```
'''backtest
start: 2019-07-01 09:00:00
end: 2020-03-25 15:00:00
period: 1d
exchanges: [{"eid":"Futures_CTP","currency":"FUTURES"}]
'''
import json
import re
import time
_bot = ext.NewPositionManager()
class Manager:
'Strategy logic control'
ACT_IDLE = 0
ACT_LONG = 1
ACT_SHORT = 2
ACT_COVER = 3
ERR_SUCCESS = 0
ERR_SET_SYMBOL = 1
ERR_GET_ORDERS = 2
ERR_GET_POS = 3
ERR_TRADE = 4
ERR_GET_DEPTH = 5
ERR_NOT_TRADING = 6
errMsg = ["Success", "Failed to switch contract", "Failed to get order info", "Failed to get position info", "Placing Order failed", "Failed to get order depth info", "Not in trading hours"]
def __init__(self, needRestore, symbol, keepBalance, fastPeriod, slowPeriod):
# Get symbolDetail
symbolDetail = _C(exchange.SetContractType, symbol)
if symbolDetail["VolumeMultiple"] == 0 or symbolDetail["MaxLimitOrderVolume"] == 0 or symbolDetail["MinLimitOrderVolume"] == 0 or symbolDetail["LongMarginRatio"] == 0 or symbolDetail["ShortMarginRatio"] == 0:
Log(symbolDetail)
raise Exception("Abnormal contract information")
else :
Log("contract", symbolDetail["InstrumentName"], "1 lot", symbolDetail["VolumeMultiple"], "lot, Maximum placing order quantity", symbolDetail["MaxLimitOrderVolume"], "Margin rate: ", _N(symbolDetail["LongMarginRatio"]), _N(symbolDetail["ShortMarginRatio"]), "Delivery date", symbolDetail["StartDelivDate"])
# Initialization
self.symbol = symbol
self.keepBalance = keepBalance
self.fastPeriod = fastPeriod
self.slowPeriod = slowPeriod
self.marketPosition = None
self.holdPrice = None
self.holdAmount = None
self.holdProfit = None
self.task = {
"action" : Manager.ACT_IDLE,
"amount" : 0,
"dealAmount" : 0,
"avgPrice" : 0,
"preCost" : 0,
"preAmount" : 0,
"init" : False,
"retry" : 0,
"desc" : "idle",
"onFinish" : None
}
self.lastPrice = 0
self.symbolDetail = symbolDetail
# Position status information
self.status = {
"symbol" : symbol,
"recordsLen" : 0,
"vm" : [],
"open" : 0,
"cover" : 0,
"st" : 0,
"marketPosition" : 0,
"lastPrice" : 0,
"holdPrice" : 0,
"holdAmount" : 0,
"holdProfit" : 0,
"symbolDetail" : symbolDetail,
"lastErr" : "",
"lastErrTime" : "",
"isTrading" : False
}
# Other processing work during object construction
vm = None
if RMode == 0:
vm = _G(self.symbol)
else:
vm = json.loads(VMStatus)[self.symbol]
if vm:
Log("Ready to resume progress, current contract status is", vm)
self.reset(vm[0])
else:
if needRestore:
Log("could not find" + self.symbol + "progress recovery information")
self.reset()
def setLastError(self, err=None):
if err is None:
self.status["lastErr"] = ""
self.status["lastErrTime"] = ""
return
t = _D()
self.status["lastErr"] = err
self.status["lastErrTime"] = t
def reset(self, marketPosition=None):
if marketPosition is not None:
self.marketPosition = marketPosition
pos = _bot.GetPosition(self.symbol, PD_LONG if marketPosition > 0 else PD_SHORT)
if pos is not None:
self.holdPrice = pos["Price"]
self.holdAmount = pos["Amount"]
Log(self.symbol, "Position", pos)
else :
raise Exception("Restore" + self.symbol + "position status is wrong, no position information found")
Log("Restore", self.symbol, "average holding position price:", self.holdPrice, "Number of positions:", self.holdAmount)
self.status["vm"] = [self.marketPosition]
else :
self.marketPosition = 0
self.holdPrice = 0
self.holdAmount = 0
self.holdProfit = 0
self.holdProfit = 0
self.lastErr = ""
self.lastErrTime = ""
def Status(self):
self.status["marketPosition"] = self.marketPosition
self.status["holdPrice"] = self.holdPrice
self.status["holdAmount"] = self.holdAmount
self.status["lastPrice"] = self.lastPrice
if self.lastPrice > 0 and self.holdAmount > 0 and self.marketPosition != 0:
self.status["holdProfit"] = _N((self.lastPrice - self.holdPrice) * self.holdAmount * self.symbolDetail["VolumeMultiple"], 4) * (1 if self.marketPosition > 0 else -1)
else :
self.status["holdProfit"] = 0
return self.status
def setTask(self, action, amount = None, onFinish = None):
self.task["init"] = False
self.task["retry"] = 0
self.task["action"] = action
self.task["preAmount"] = 0
self.task["preCost"] = 0
self.task["amount"] = 0 if amount is None else amount
self.task["onFinish"] = onFinish
if action == Manager.ACT_IDLE:
self.task["desc"] = "idle"
self.task["onFinish"] = None
else:
if action != Manager.ACT_COVER:
self.task["desc"] = ("Adding long position" if action == Manager.ACT_LONG else "Adding short position") + "(" + str(amount) + ")"
else :
self.task["desc"] = "Closing Position"
Log("Task received", self.symbol, self.task["desc"])
self.Poll(True)
def processTask(self):
insDetail = exchange.SetContractType(self.symbol)
if not insDetail:
return Manager.ERR_SET_SYMBOL
SlideTick = 1
ret = False
if self.task["action"] == Manager.ACT_COVER:
hasPosition = False
while True:
if not ext.IsTrading(self.symbol):
return Manager.ERR_NOT_TRADING
hasPosition = False
positions = exchange.GetPosition()
if positions is None:
return Manager.ERR_GET_POS
depth = exchange.GetDepth()
if depth is None:
return Manager.ERR_GET_DEPTH
orderId = None
for i in range(len(positions)):
if positions[i]["ContractType"] != self.symbol:
continue
amount = min(insDetail["MaxLimitOrderVolume"], positions[i]["Amount"])
if positions[i]["Type"] == PD_LONG or positions[i]["Type"] == PD_LONG_YD:
exchange.SetDirection("closebuy_today" if positions[i].Type == PD_LONG else "closebuy")
orderId = exchange.Sell(_N(depth["Bids"][0]["Price"] - (insDetail["PriceTick"] * SlideTick), 2), min(amount, depth["Bids"][0]["Amount"]), self.symbol, "Close today's position" if positions[i]["Type"] == PD_LONG else "Close yesterday's position", "Bid", depth["Bids"][0])
hasPosition = True
elif positions[i]["Type"] == PD_SHORT or positions[i]["Type"] == PD_SHORT_YD:
exchange.SetDirection("closesell_today" if positions[i]["Type"] == PD_SHORT else "closesell")
orderId = exchange.Buy(_N(depth["Asks"][0]["Price"] + (insDetail["PriceTick"] * SlideTick), 2), min(amount, depth["Asks"][0]["Amount"]), self.symbol, "Close today's position" if positions[i]["Type"] == PD_SHORT else "Close yesterday's position", "Ask", depth["Asks"][0])
hasPosition = True
if hasPosition:
if not orderId:
return Manager.ERR_TRADE
Sleep(1000)
while True:
orders = exchange.GetOrders()
if orders is None:
return Manager.ERR_GET_ORDERS
if len(orders) == 0:
break
for i in range(len(orders)):
exchange.CancelOrder(orders[i]["Id"])
Sleep(500)
if not hasPosition:
break
ret = True
elif self.task["action"] == Manager.ACT_LONG or self.task["action"] == Manager.ACT_SHORT:
while True:
if not ext.IsTrading(self.symbol):
return Manager.ERR_NOT_TRADING
Sleep(1000)
while True:
orders = exchange.GetOrders()
if orders is None:
return Manager.ERR_GET_ORDERS
if len(orders) == 0:
break
for i in range(len(orders)):
exchange.CancelOrder(orders[i]["Id"])
Sleep(500)
positions = exchange.GetPosition()
if positions is None:
return Manager.ERR_GET_POS
pos = None
for i in range(len(positions)):
if positions[i]["ContractType"] == self.symbol and (((positions[i]["Type"] == PD_LONG or positions[i]["Type"] == PD_LONG_YD) and self.task["action"] == Manager.ACT_LONG) or ((positions[i]["Type"] == PD_SHORT) or positions[i]["Type"] == PD_SHORT_YD) and self.task["action"] == Manager.ACT_SHORT):
if not pos:
pos = positions[i]
pos["Cost"] = positions[i]["Price"] * positions[i]["Amount"]
else :
pos["Amount"] += positions[i]["Amount"]
pos["Profit"] += positions[i]["Profit"]
pos["Cost"] += positions[i]["Price"] * positions[i]["Amount"]
# records pre position
if not self.task["init"]:
self.task["init"] = True
if pos:
self.task["preAmount"] = pos["Amount"]
self.task["preCost"] = pos["Cost"]
else:
self.task["preAmount"] = 0
self.task["preCost"] = 0
remain = self.task["amount"]
if pos:
self.task["dealAmount"] = pos["Amount"] - self.task["preAmount"]
remain = int(self.task["amount"] - self.task["dealAmount"])
if remain <= 0 or self.task["retry"] >= MaxTaskRetry:
ret = {
"price" : (pos["Cost"] - self.task["preCost"]) / (pos["Amount"] - self.task["preAmount"]),
"amount" : (pos["Amount"] - self.task["preAmount"]),
"position" : pos
}
break
elif self.task["retry"] >= MaxTaskRetry:
ret = None
break
depth = exchange.GetDepth()
if depth is None:
return Manager.ERR_GET_DEPTH
orderId = None
if self.task["action"] == Manager.ACT_LONG:
exchange.SetDirection("buy")
orderId = exchange.Buy(_N(depth["Asks"][0]["Price"] + (insDetail["PriceTick"] * SlideTick), 2), min(remain, depth["Asks"][0]["Amount"]), self.symbol, "Ask", depth["Asks"][0])
else:
exchange.SetDirection("sell")
orderId = exchange.Sell(_N(depth["Bids"][0]["Price"] - (insDetail["PriceTick"] * SlideTick), 2), min(remain, depth["Bids"][0]["Amount"]), self.symbol, "Bid", depth["Bids"][0])
if orderId is None:
self.task["retry"] += 1
return Manager.ERR_TRADE
if self.task["onFinish"]:
self.task["onFinish"](ret)
self.setTask(Manager.ACT_IDLE)
return Manager.ERR_SUCCESS
def Poll(self, subroutine = False):
# Judge the trading hours
self.status["isTrading"] = ext.IsTrading(self.symbol)
if not self.status["isTrading"]:
return
# Perform order trading tasks
if self.task["action"] != Manager.ACT_IDLE:
retCode = self.processTask()
if self.task["action"] != Manager.ACT_IDLE:
self.setLastError("The task was not successfully processed:" + Manager.errMsg[retCode] + ", " + self.task["desc"] + ", Retry:" + str(self.task["retry"]))
else :
self.setLastError()
return
if subroutine:
return
suffix = "@" if WXPush else ""
# switch symbol
_C(exchange.SetContractType, self.symbol)
# Get K-line data
records = exchange.GetRecords()
if records is None:
self.setLastError("Failed to get K line")
return
self.status["recordsLen"] = len(records)
if len(records) < self.fastPeriod + 2 or len(records) < self.slowPeriod + 2:
self.setLastError("The length of the K line is less than the moving average period:" + str(self.fastPeriod) + "or" + str(self.slowPeriod))
return
opCode = 0 # 0 : IDLE , 1 : LONG , 2 : SHORT , 3 : CoverALL
lastPrice = records[-1]["Close"]
self.lastPrice = lastPrice
fastMA = TA.EMA(records, self.fastPeriod)
slowMA = TA.EMA(records, self.slowPeriod)
# Strategy logic
if self.marketPosition == 0:
if fastMA[-3] < slowMA[-3] and fastMA[-2] > slowMA[-2]:
opCode = 1
elif fastMA[-3] > slowMA[-3] and fastMA[-2] < slowMA[-2]:
opCode = 2
else:
if self.marketPosition < 0 and fastMA[-3] < slowMA[-3] and fastMA[-2] > slowMA[-2]:
opCode = 3
elif self.marketPosition > 0 and fastMA[-3] > slowMA[-3] and fastMA[-2] < slowMA[-2]:
opCode = 3
# If no condition is triggered, the opcode is 0 and return
if opCode == 0:
return
# Preforming closing position action
if opCode == 3:
def coverCallBack(ret):
self.reset()
_G(self.symbol, None)
self.setTask(Manager.ACT_COVER, 0, coverCallBack)
return
account = _bot.GetAccount()
canOpen = int((account["Balance"] - self.keepBalance) / (self.symbolDetail["LongMarginRatio"] if opCode == 1 else self.symbolDetail["ShortMarginRatio"]) / (lastPrice * 1.2) / self.symbolDetail["VolumeMultiple"])
unit = min(1, canOpen)
# Set up trading tasks
def setTaskCallBack(ret):
if not ret:
self.setLastError("Placing Order failed")
return
self.holdPrice = ret["position"]["Price"]
self.holdAmount = ret["position"]["Amount"]
self.marketPosition += 1 if opCode == 1 else -1
self.status["vm"] = [self.marketPosition]
_G(self.symbol, self.status["vm"])
self.setTask(Manager.ACT_LONG if opCode == 1 else Manager.ACT_SHORT, unit, setTaskCallBack)
def onexit():
Log("Exited strategy...")
def main():
if exchange.GetName().find("CTP") == -1:
raise Exception("Only support commodity futures CTP")
SetErrorFilter("login|ready|flow control|connection failed|initial|Timeout")
mode = exchange.IO("mode", 0)
if mode is None:
raise Exception("Failed to switch modes, please update to the latest docker!")
while not exchange.IO("status"):
Sleep(3000)
LogStatus("Waiting for connection with the trading server," + _D())
positions = _C(exchange.GetPosition)
if len(positions) > 0:
Log("Detecting the current holding position, the system will start to try to resume the progress...")
Log("Position information:", positions)
initAccount = _bot.GetAccount()
initMargin = json.loads(exchange.GetRawJSON())["CurrMargin"]
keepBalance = _N((initAccount["Balance"] + initMargin) * (KeepRatio / 100), 3)
Log("Asset information", initAccount, "Retain funds:", keepBalance)
tts = []
symbolFilter = {}
arr = Instruments.split(",")
arrFastPeriod = FastPeriodArr.split(",")
arrSlowPeriod = SlowPeriodArr.split(",")
if len(arr) != len(arrFastPeriod) or len(arr) != len(arrSlowPeriod):
raise Exception("The moving average period parameter does not match the number of added contracts, please check the parameters!")
for i in range(len(arr)):
symbol = re.sub(r'/\s+$/g', "", re.sub(r'/^\s+/g', "", arr[i]))
if symbol in symbolFilter.keys():
raise Exception(symbol + "Already exists, please check the parameters!")
symbolFilter[symbol] = True
hasPosition = False
for j in range(len(positions)):
if positions[j]["ContractType"] == symbol:
hasPosition = True
break
fastPeriod = int(arrFastPeriod[i])
slowPeriod = int(arrSlowPeriod[i])
obj = Manager(hasPosition, symbol, keepBalance, fastPeriod, slowPeriod)
tts.append(obj)
preTotalHold = -1
lastStatus = ""
while True:
if GetCommand() == "Pause/Resume":
Log("Suspending trading ...")
while GetCommand() != "Pause/Resume":
Sleep(1000)
Log("Continue trading...")
while not exchange.IO("status"):
Sleep(3000)
LogStatus("Waiting for connection with the trading server," + _D() + "\n" + lastStatus)
tblStatus = {
"type" : "table",
"title" : "Position information",
"cols" : ["Contract Name", "Direction of Position", "Average Position Price", "Number of Positions", "Position profits and Losses", "Number of Positions Added", "Current Price"],
"rows" : []
}
tblMarket = {
"type" : "table",
"title" : "Operating status",
"cols" : ["Contract name", "Contract multiplier", "Margin rate", "Trading time", "Bar length", "Exception description", "Time of occurrence"],
"rows" : []
}
totalHold = 0
vmStatus = {}
ts = time.time()
holdSymbol = 0
for i in range(len(tts)):
tts[i].Poll()
d = tts[i].Status()
if d["holdAmount"] > 0:
vmStatus[d["symbol"]] = d["vm"]
holdSymbol += 1
tblStatus["rows"].append([d["symbolDetail"]["InstrumentName"], "--" if d["holdAmount"] == 0 else ("long" if d["marketPosition"] > 0 else "short"), d["holdPrice"], d["holdAmount"], d["holdProfit"], abs(d["marketPosition"]), d["lastPrice"]])
tblMarket["rows"].append([d["symbolDetail"]["InstrumentName"], d["symbolDetail"]["VolumeMultiple"], str(_N(d["symbolDetail"]["LongMarginRatio"], 4)) + "/" + str(_N(d["symbolDetail"]["ShortMarginRatio"], 4)), "is #0000ff" if d["isTrading"] else "not #ff0000", d["recordsLen"], d["lastErr"], d["lastErrTime"]])
totalHold += abs(d["holdAmount"])
now = time.time()
elapsed = now - ts
tblAssets = _bot.GetAccount(True)
nowAccount = _bot.Account()
if len(tblAssets["rows"]) > 10:
tblAssets["rows"][0] = ["InitAccount", "Initial asset", initAccount]
else:
tblAssets["rows"].insert(0, ["NowAccount", "Currently available", nowAccount])
tblAssets["rows"].insert(0, ["InitAccount", "Initial asset", initAccount])
lastStatus = "`" + json.dumps([tblStatus, tblMarket, tblAssets]) + "`\nPolling time:" + str(elapsed) + " Seconds, current time:" + _D() + ", Number of varieties held:" + str(holdSymbol)
if totalHold > 0:
lastStatus += "\nManually restore the string:" + json.dumps(vmStatus)
LogStatus(lastStatus)
if preTotalHold > 0 and totalHold == 0:
LogProfit(nowAccount.Balance - initAccount.Balance - initMargin)
preTotalHold = totalHold
Sleep(LoopInterval * 1000)
```
Strategy address: https://www.fmz.com/strategy/208512
## Backtest comparison
We compared the JavaScript version and Python version of the strategy with backtest.
- Python version backtest
We use a public server for backtest, and we can see that the backtest of the Python version is slightly faster.
- JavaScript version backtest
It can be seen that the backtest results are exactly the same. Interested friends can delve into the code, and there will be no small gains.
## Expand
Let's make an extension demonstration and extend the chart function to the strategy, as shown in the figure:
## Mainly increase the coding part:
- Add a member to the Manager class: objChart
- Add a method to the Manager class: PlotRecords
Some other modifications are made around these two points. You can compare the differences between the two versions and learn the ideas of extended functions.
From: https://blog.mathquant.com/2020/05/28/python-version-commodity-futures-moving-average-strategy.html | fmzquant |
1,886,394 | [Docker] Laravel, Nginx MySQL | Dockerización PHP 8.2 Laravel 11 (Latest) Nginx (Latest) MySQL (Latest) Uso docker-compose... | 0 | 2024-06-13T03:16:42 | https://dev.to/jkdevarg/docker-laravel-nginx-mysql-4lp0 | docker, laravel, nginx, mysql | **Dockerización**
- PHP 8.2
- Laravel 11 (Latest)
- Nginx (Latest)
- MySQL (Latest)
**Uso**
- docker-compose build
- docker-compose up -d
**Config**
- Configurar el .env de laravel
---
**Dockerfile**
```
FROM php:8.2-fpm-alpine
# Update app
RUN apk update && apk add --no-cache tzdata
# Set timezone
ENV TZ="UTC"
RUN apk add --update --no-cache autoconf g++ make openssl-dev
RUN apk add libpng-dev
RUN apk add libzip-dev
RUN docker-php-ext-install gd
RUN docker-php-ext-install zip
RUN docker-php-ext-install bcmath
RUN docker-php-ext-install sockets
RUN curl -sS https://getcomposer.org/installer | php -- --install-dir=/usr/local/bin --filename=composer
### End Init install
# Install Redis
RUN pecl install redis
RUN docker-php-ext-enable redis
# Install Mongodb
RUN pecl install mongodb
RUN docker-php-ext-enable mongodb
RUN docker-php-ext-install mysqli pdo pdo_mysql && docker-php-ext-enable pdo_mysql
WORKDIR /home/source/main
```
---
**docker-compose.yml**
```
version: '3.7'
services:
mysql:
image: mysql:latest
container_name: mysql
platform: linux/x86_64
ports:
- "3306:3306"
volumes:
- mysql-volumes:/var/lib/mysql
environment:
MYSQL_ROOT_PASSWORD: laravelroot
MYSQL_DATABASE: db_nginx
laravel-app:
build:
context: ./docker/php
container_name: laravel-app
volumes:
- ./laravel/:/home/source/main
working_dir: /home/source/main
nginx:
build:
context: ./docker/nginx
container_name: todo-nginx
ports:
- "8000:80"
depends_on:
- laravel-app
volumes:
- ./laravel/:/home/source/main
volumes:
mysql-volumes:
networks:
default:
name: laravel-app-netword
```
Repositorio:
[https://github.com/JkDevArg/Docker-NLM](https://github.com/JkDevArg/Docker-NLM) | jkdevarg |
1,886,392 | sweatandsocialdistance | Онлайн казино Вавада радует своих посетителей по-настоящему впечатляющим выбором игровых развлечений,... | 0 | 2024-06-13T03:11:09 | https://dev.to/sweatandsocialdistance/sweatandsocialdistance-67h | Онлайн казино [Вавада](https://sweatandsocialdistance.com/) радует своих посетителей по-настоящему впечатляющим выбором игровых развлечений, а также высочайшим уровнем сервиса и обслуживания. На официальном сайте этого надежного игорного заведения вы найдете все необходимые разделы и функции для по-настоящему комфортной игры, включая быстрые и удобные выплаты выигрышей. Разнообразие представленных игр, от классических слотов до современных настольных и карточных игр, не оставит равнодушным ни одного азартного игрока. | sweatandsocialdistance | |
1,886,391 | Ghostface Text to Speech Mastery Guide 2024 | Discover the innovative Ghostface text to speech voice options for a unique creative experience.... | 0 | 2024-06-13T03:08:52 | https://dev.to/novita_ai/ghostface-text-to-speech-mastery-guide-2024-2l0 | ai, tts, ghostface |
Discover the innovative Ghostface text to speech voice options for a unique creative experience. Learn more on our blog.
## Key Highlights
- Discover how to incorporate the distinctive Ghostface voice into your projects using advanced Text to Speech technology.
- Explore tips for selecting the best Ghostface Text to Speech solution based on compatibility, voice quality, and customization.
- Utilize Novita AI, a leading TTS solution featuring high-quality Ghostface voice generation and seamless API integration.
- Ensure your Ghostface TTS implementation is compatible with various platforms and formats, reaching a wider users.
## Introduction
Unveil the realm of creativity with Ghostface Text to Speech voices, enabling a hauntingly unique experience in content creation. Delve into the eerie yet captivating world of voice generators, offering a diverse range of options to elevate your projects. Explore the iconic voice of Ghostface in different formats, from audio to prank calls, enhancing multimedia endeavors with a touch of horror movie flair. Embrace the power of Ghostface AI voices and unleash your imagination like never before.
## What is the Ghostface Text to Speech
Ghostface TTS is an advanced voice generation that allows developers to create the iconic Ghostface voice for their projects. By leveraging sophisticated AI algorithms, the Ghostface voice generator can produce high-quality, spine-chilling voiceovers in various audio formats. Whether you're building spooky podcasts, horror games, or innovative voice apps, Ghostface TTS offers a unique and user-friendly way to incorporate this famous voice.
## How Ghostface Text to Speech Works
Ghostface Text to Speech is powered by a deep learning neural network trained on vast speech data. This allows the system to analyze text and generate corresponding audio with customizable pitch, speed, and tone.
**Key features:**
- Pitch Control: Adjust voice frequency for deep or high-pitched tones.
- Speed Adjustment: Slow down for drama or speed up for snappy delivery.
- Tone Personalization: Set the voice personality, from professional to sarcastic.
The deep learning algorithms enable Ghostface to transform written content into a tailored audio experience, unlocking new possibilities.
## Lists of the Good Ghostface Text to Speech
### How to select the best one
When seeking the best Ghostface TTS for your projects, consider its compatibility with different formats, the quality of voice generation, and ease of customization. Price is also an essential factor should be taken into consideration especially if using it for commerce or developing.
### Recommendation of Ghostface Text to Speech AI
The market offers a variety of advanced Ghostface Text to Speech (TTS) AI catering to diverse needs. Here are some TTS AI can be taken into consideration:
**Novita AI**: effective as a recommended Ghostface TTS provider, offering a developer-friendly API that allows you to easily integrate the iconic Ghostface voice into your applications, with high-quality generation and advanced customization options.
**LOVO**: excels in offering a broad selection of voices and languages tailored for training videos. Its robust customization options allow users to modulate the voice tone, speed, and even incorporate different accents for enhanced authenticity and cultural relevance.
**Speechify**: stands out as a user-friendly tool enabling high-quality voice generation across multiple formats, languages, and platforms. Its customizable voices and templates make it easy for trainers to incorporate polished audio into their training videos.
**Murf**: strengths include collaborative tools, enterprise-level security, diverse vocal quality, and support for various use cases like e-learning, video, and audiobooks. The tool also provides free creative resources to empower content creators across industries.
Below is a chart roughly making a comparison of these AI:
## How to Test Your Ghostface TTS Voice demo
Here is the guide helping you use the TTS in Novita AI :
**Step 1**. To begin creating your Ghostface TTS voice, start by selecting a reliable voice generator software compatible with different formats.
**Step 2**. Adjust the settings for your desired voice of Ghostface, exploring options like voice changers and iconic voice effects.
**Step 3**. Experiment with various algorithms and settings to customize your speech voice generator.
Step 4. Once satisfied, save the final output in your preferred audio format.
**Step 5**. Test your Ghostface voice across different platforms to ensure optimal performance before integrating it into your projects.
### Insert APIs into Your Project
What's more, Novita AI offers developers robust [Text-to-Speech (TTS) APIs](https://novita.ai/reference/audio/text_to_speech.html) to easily integrate advanced voice cloning. The APIs provide access to cutting-edge voice models, allowing developers to quickly generate high-quality synthetic voices without complex customization.
By using Novita AI's TTS solutions, developers can seamlessly incorporate Ghostface's iconic voice or other celebrity tones into diverse applications - from virtual assistants to video games. The APIs handle the technical work, freeing developers to focus on creating engaging user experiences.
Additionally, Novita AI regularly updates its TTS with the latest improvements, ensuring developers always have access to the most natural-sounding, versatile synthetic voices.
### How to clone the Ghostface voice
If you are not satisfied with the given sound demo, you can even clone the voice in Novita AI. More details are provided in this blog :[Unlock the Star Power: Snoop Dogg Text-to-Speech Technology](https://blogs.novita.ai/unlock-the-star-power-snoop-dogg-text-to-speech-technology/).
This helps developers future-proof their projects and deliver leading-edge voice experiences for users.
## Enhancing Your Projects with Ghostface Text to Speech
Ghostface's distinctive voice adds a unique, eerie touch that makes projects stand out. Ghostface Text to Speech provides developers with a powerful tool to seamlessly incorporate this iconic voice into a wide range of multimedia applications, from horror games to spooky podcasts.
### Practices for Incorporating Ghostface Voices in Multimedia Projects
For a smooth integration of Ghostface voices in multimedia projects using Novita AI, prioritize matching the voice's eerie tone with your project's theme, ensuring it adds depth without overpowering the narrative. Modify pitch, speed, and tone to achieve clarity and rhythm that support comprehension and evoke the desired emotional impact, leaving a lasting impression on your audience.
### Customizing Ghostface Voice Settings for Optimal Performance
By carefully adjusting the Ghostface voice settings, you can leverage its distinctive tone and delivery to captivate your audience and leave a lasting impression. Experiment with different configurations to find the perfect balance that aligns with your project's theme and narrative, amplifying the emotional impact and creating a truly memorable experience for your users.
## How to navigate the the Legal Landscape of Ghostface Text to Speech
Ghostface Text to Speech offers a unique voice transformation experience, but its legality hinges on responsible usage. As a developer of Ghostface Text-to-Speech technology, it's crucial to navigate the legal landscape carefully. When it comes to commercial use, the legal landscape becomes more complex. In these cases, obtaining the necessary permissions and rights to utilize someone's voice is crucial, just as it would be with any other copyrighted material.
The key is to find a balance between enjoying the capabilities of Ghostface Text to Speech and respecting the rights and privacy of others. Obtaining consent from the person whose voice you wish to recreate is a critical step in ensuring legal and ethical usage.
## Conclusion
Ghostface Text-to-Speech (TTS) technology opens up a world of creative possibilities for developers. Leverage Ghostface's iconic voice to captivate audiences across multimedia projects, from eerie podcasts to immersive video narratives.
As you integrate this synthetic voice, be mindful of legal considerations and continuously evaluate its performance against human recordings. Stay updated on the latest TTS advancements to push the boundaries of what's possible and deliver truly haunting, memorable experiences for your users.
## Frequently Asked Questions
### What Are the Legal Considerations for Using Ghostface Text to Speech Voices?
Consider legal implications when using Ghostface TTS voices to ensure compliance with copyright and voice licensing. Verify usage rights for commercial projects and respect intellectual property laws. Always review terms of service for voice generation platforms before incorporating Ghostface voices.
### How Do Ghostface TTS Voices Compare to Real Human Voices?
Ghostface TTS voices offer impressive realism but may lack some nuances of real human voices. While they excel in consistency and versatility, human voices still hold the edge in conveying emotions and subtleties.
### What Are the Future Developments Expected in Ghostface TTS Technology?
Future developments in Ghostface TTS technology may include enhanced naturalness, expanded language support, advanced customization options, and integration with emerging platforms. Stay tuned for updates on improved voice quality and innovative features in Ghostface TTS technology.
_Originally published at [Novita AI_](https://blogs.novita.ai/transform-your-voice-ghostface-text-to-speech-options/?utm_source=devcommunity_audio&utm_medium=article&utm_campaign=ghostface)
[Novita AI](https://novita.ai/?utm_source=devcoumminity_audio&utm_medium=article&utm_campaign=transform-your-voice-ghostface-text-to-speech-options), the one-stop platform for limitless creativity that gives you access to 100+ APIs. From image generation and language processing to audio enhancement and video manipulation, cheap pay-as-you-go, it frees you from GPU maintenance hassles while building your own products. Try it for free. | novita_ai |
1,886,390 | Accelerating Machine Learning with AWS SageMaker | Accelerating Machine Learning with AWS SageMaker Introduction to AWS... | 0 | 2024-06-13T03:02:23 | https://dev.to/virajlakshitha/accelerating-machine-learning-with-aws-sagemaker-44ln | 
# Accelerating Machine Learning with AWS SageMaker
### Introduction to AWS SageMaker
AWS SageMaker is a fully managed machine learning (ML) service that empowers data scientists and developers to build, train, and deploy ML models at scale. It offers a comprehensive suite of tools and services, simplifying the entire ML workflow from data preprocessing to model deployment and monitoring.
SageMaker stands out for its ease of use, scalability, and cost-effectiveness, making it an ideal choice for organizations of all sizes looking to leverage the power of ML.
### Key Components of SageMaker:
Let's delve deeper into the core components of AWS SageMaker:
* **SageMaker Studio:** A unified visual interface acting as a central hub for all your ML development activities within SageMaker. It provides an interactive environment for building, training, debugging, deploying, and monitoring your models.
* **SageMaker Notebooks:** Managed Jupyter notebooks optimized for ML tasks. They come pre-configured with popular ML libraries and frameworks, allowing you to quickly start experimenting with your data and algorithms.
* **SageMaker Experiments:** A capability for organizing, tracking, comparing, and evaluating ML experiments. You can track input datasets, hyperparameters, code versions, and results – gaining insights to optimize model performance.
* **SageMaker Autopilot:** Enables automated model development. You provide a tabular dataset and desired business objective, and Autopilot will automatically explore different algorithms and hyperparameter settings to find the best-performing model.
* **SageMaker Training:** A fully managed service for training your ML models. It supports distributed training, allowing you to scale your training jobs across clusters of powerful compute instances.
* **SageMaker Model Registry:** Provides a central repository to manage your trained ML models. This promotes better model versioning, governance, and deployment tracking within your organization.
* **SageMaker Inference:** Handles deploying your trained models for real-time or batch predictions. It supports serverless options (for automatic scaling) and real-time endpoints for low-latency predictions.
* **SageMaker Model Monitor:** Enables you to detect and respond to potential issues with your deployed models. It monitors data drift (changes in input data over time) and model quality, alerting you if performance degrades.
* **SageMaker Ground Truth:** Helps you build highly accurate training datasets for ML tasks, particularly useful for supervised learning tasks that require labeled data.
### Use Cases for AWS SageMaker
Here are some compelling use cases showcasing how SageMaker can be applied across different domains:
**1. Fraud Detection in Financial Transactions**
* **Challenge:** Identifying fraudulent transactions in real-time within massive datasets of financial transactions.
* **SageMaker Solution:**
* **Data Preparation:** Use SageMaker Data Wrangler to preprocess and transform transaction data, handling missing values and encoding categorical features.
* **Model Training:** Train a fraud detection model using SageMaker XGBoost (a popular gradient boosting algorithm) on historical transaction data labeled as fraudulent or legitimate. Distribute training on a large dataset to improve efficiency.
* **Model Deployment:** Deploy the trained model to a SageMaker real-time endpoint, which can provide predictions on new transactions with low latency.
* **Monitoring:** Utilize SageMaker Model Monitor to track the model's performance and detect concept drift (e.g., new fraud patterns emerging).
**2. Image Recognition for Medical Diagnosis**
* **Challenge:** Developing accurate image recognition models to assist medical professionals in diagnosing diseases from medical images (e.g., X-rays, MRIs).
* **SageMaker Solution:**
* **Data Preparation:** Utilize SageMaker Ground Truth to label a large dataset of medical images with diagnoses (if manual labeling is needed).
* **Model Training:** Train a deep learning model (e.g., a convolutional neural network - CNN) on the labeled image data using SageMaker's TensorFlow or PyTorch integration. Leverage GPU instances for faster training.
* **Model Deployment:** Deploy the trained model as a SageMaker endpoint. Medical professionals can then send images to the endpoint to receive predictions, aiding in their diagnosis process.
**3. Personalized Product Recommendations**
* **Challenge:** Providing highly personalized product recommendations to enhance customer experience and drive sales in e-commerce.
* **SageMaker Solution:**
* **Data Preparation:** Prepare customer purchase history, browsing behavior, and product catalog data using SageMaker Data Wrangler.
* **Model Training:** Train a recommendation model, such as a collaborative filtering model or a factorization machine, using SageMaker's built-in algorithms or custom code.
* **Model Deployment:** Deploy the model to a real-time endpoint. When a customer interacts with the e-commerce platform, the model generates personalized product recommendations based on their behavior and preferences.
**4. Predictive Maintenance in Manufacturing**
* **Challenge:** Predicting equipment failures in advance to minimize downtime, optimize maintenance schedules, and reduce costs.
* **SageMaker Solution:**
* **Data Collection:** Collect sensor data (e.g., temperature, vibration, pressure) from manufacturing equipment over time.
* **Data Preprocessing:** Use SageMaker Data Wrangler to clean, transform, and engineer features from the sensor data.
* **Model Training:** Train a time-series forecasting model (e.g., LSTM, Prophet) on historical sensor data to predict equipment failures.
* **Model Deployment:** Deploy the model to a SageMaker endpoint. The system can send alerts to maintenance teams when the model predicts an impending equipment failure.
**5. Natural Language Processing for Customer Service Automation**
* **Challenge:** Automating customer service tasks, such as answering frequently asked questions and routing inquiries to the appropriate departments.
* **SageMaker Solution:**
* **Data Preparation:** Gather customer support transcripts, emails, or chat logs.
* **Model Training:** Train a natural language understanding (NLU) model (e.g., BERT) using SageMaker to understand customer intent and extract relevant information from text.
* **Model Deployment:** Deploy the model to a real-time endpoint. Integrate the endpoint into a chatbot or virtual assistant to automate customer interactions.
### Comparing SageMaker with Other Cloud Providers
While AWS SageMaker is a powerful and feature-rich ML platform, it's important to consider alternative cloud ML services:
* **Google Cloud AI Platform:** Google's offering provides similar capabilities to SageMaker, including managed Jupyter notebooks, distributed training, and model deployment. It strongly integrates with other Google Cloud services and benefits from Google's expertise in areas like TensorFlow.
* **Azure Machine Learning:** Microsoft's cloud ML service offers a visual drag-and-drop interface for building ML pipelines, making it potentially more user-friendly for beginners. It features strong integration with other Azure services and supports a wide range of open-source frameworks.
**Key Differentiators of SageMaker:**
* **Ease of use:** SageMaker is designed with developer experience in mind, often abstracting away complexities associated with infrastructure management.
* **Breadth and depth of features:** It offers a comprehensive set of tools, from data labeling to model monitoring, covering the entire ML workflow.
* **Integration with the AWS ecosystem:** Seamlessly integrates with other AWS services like S3, Redshift, and Kinesis for data storage, processing, and streaming.
### Conclusion
AWS SageMaker has emerged as a leading cloud-based machine learning platform, empowering businesses to build, train, and deploy ML models efficiently. Its comprehensive suite of tools, scalability, and integration with the AWS ecosystem make it a compelling choice for organizations of all sizes looking to accelerate their machine learning journey.
### Advanced Use Case: Real-time Fraud Detection with Streaming Data and Explainable AI
**Scenario:** A financial institution wants to detect fraudulent transactions in real-time with high accuracy. Additionally, they require the ability to understand the reasoning behind each fraud prediction to improve model transparency and meet regulatory requirements.
**Architecture:**
1. **Data Ingestion:** Real-time transaction data is streamed from various sources (e.g., ATMs, online transactions) into Amazon Kinesis Data Streams.
2. **Data Preprocessing:** Amazon Kinesis Data Analytics performs real-time data preprocessing, such as cleaning, transforming, and enriching the data. This could include:
* Handling missing values.
* Encoding categorical variables.
* Performing feature engineering (e.g., calculating transaction velocity, aggregating features over time windows).
3. **Fraud Detection Model:** A pre-trained fraud detection model (e.g., XGBoost, Random Forest) is deployed to a SageMaker real-time endpoint. This model has been trained on historical data labeled as fraudulent or legitimate.
4. **Real-time Prediction:** As new transactions flow through Kinesis, they are sent to the SageMaker endpoint for real-time predictions. The model outputs a probability of fraud for each transaction.
5. **Explainable AI (XAI):** To provide model transparency, we integrate an XAI solution like SHAP (SHapley Additive exPlanations) or LIME (Local Interpretable Model-agnostic Explanations). This component analyzes the model's predictions and provides insights into which features are most influential in flagging a transaction as potentially fraudulent.
6. **Rule Engine and Alerting:** A rule engine evaluates the model's prediction probabilities and XAI insights. If a transaction exceeds a predefined risk threshold or exhibits suspicious patterns identified by the XAI component, the system generates an alert for further investigation.
7. **Human Review and Feedback Loop:** Security analysts investigate alerts, validate potential fraud cases, and provide feedback to the system. This feedback loop helps in retraining and improving the fraud detection model over time.
**Benefits:**
* **Real-time Fraud Prevention:** Detect and prevent fraudulent transactions in real time, minimizing financial losses.
* **Enhanced Accuracy:** Combining machine learning with streaming data processing enables highly accurate fraud detection.
* **Model Explainability:** XAI techniques provide transparency into model decisions, building trust and meeting regulatory compliance.
* **Continuous Improvement:** The feedback loop facilitates ongoing model refinement and adaptation to evolving fraud patterns.
This advanced use case demonstrates how AWS SageMaker, in conjunction with other AWS services, can address complex, real-world scenarios requiring real-time data processing, machine learning, and explainable AI.
| virajlakshitha | |
1,886,389 | Deadlock | This is a submission for DEV Computer Science Challenge v24.06.12: One Byte Explainer. ... | 0 | 2024-06-13T02:57:29 | https://dev.to/anshsaini/deadlocks-3h3n | devchallenge, cschallenge, computerscience, beginners | _This is a submission for DEV Computer Science Challenge v24.06.12: One Byte Explainer._
## Explainer
When two or more processes are unable to proceed because each is waiting for another to release a resource. It results in a stalemate where none can progress, requiring intervention like resource reallocation or termination to resolve.
| anshsaini |
1,886,388 | Explore Color Options for Jordan 4 Replicas | When it comes to Jordan 4 replicas, the world of color options is vast and exciting, offering sneaker... | 0 | 2024-06-13T02:51:45 | https://dev.to/dana_blair_91609e4d6908cf/explore-color-options-for-jordan-4-replicas-412b | design | When it comes to Jordan 4 replicas, the world of color options is vast and exciting, offering sneaker enthusiasts a chance to express their style through vibrant hues and unique combinations. Whether you're looking to match your favorite outfit or make a bold fashion statement, choosing the right color for your Jordan 4 replicas is essential. Here’s a detailed exploration of popular color options and how they can elevate your sneaker game.
## Classic Colorways about [jordan 4 replicas](https://www.colareps.com/collections/replica-air-jordan-4/)
Bred (Black/Red)
The Bred colorway is an iconic choice, known for its timeless appeal and versatility:
Bold contrast: Black uppers with striking red accents on the midsole, heel, and outsole.
Streetwear staple: Perfect for both casual and street style outfits.
White Cement
A tribute to the original Jordan 4 release, the White Cement colorway exudes timeless elegance:
Clean aesthetic: White leather uppers with grey cement print accents and black detailing.
Versatile: Pair effortlessly with a wide range of outfits, from jeans to athleisure.
Military Blue
Military Blue offers a unique twist with its cool blue tones:
Distinctive look: Blue leather uppers with grey and white accents, including the iconic Jordan wings logo.
Sporty appeal: Ideal for adding a pop of color to your everyday attire.
## Custom Color Combinations
Personalized Creations
For those seeking individuality and personal expression, custom color combinations are the way to go:
Mix and match: Experiment with different color blocks, gradients, or patterns.
Signature style: Create sneakers that reflect your unique taste and personality.
## Limited Edition and Rare Colorways
Collector’s Delight
Keep an eye out for limited edition Jordan 4 replicas in exclusive colorways:
Rare finds: Unique color schemes released in limited quantities.
Investment pieces: Highly sought after by collectors and sneaker enthusiasts alike.
Seasonal Trends and Fashion Statements
Trendy Choices
Stay ahead of the fashion curve with seasonal color trends for Jordan 4 replicas:
Spring pastels: Soft hues like mint green or lavender for a fresh look.
Fall earth tones: Rich browns, deep greens, or mustard yellows for a cozy vibe.
## Care Tips for Colorful Jordan 4 Replicas
Maintaining Freshness
To preserve the vibrancy of your Jordan 4 replicas:
Regular cleaning: Wipe gently with a damp cloth to remove dirt and debris.
Storage: Keep in a cool, dry place away from direct sunlight to prevent fading.
Touch-ups: Use appropriate sneaker cleaners and protectants for specific materials.
Choosing Your Perfect Color
Personal Preference
Ultimately, the best color for your Jordan 4 replicas depends on your personal style and wardrobe preferences:
Experiment: Don’t be afraid to try new colors and combinations.
Signature look: Find colors that resonate with you and make a statement.
Exploring color options for Jordan 4 replicas opens up a world of creativity and style possibilities. Whether you prefer classic hues, custom creations, or limited edition rarities, your sneakers can become a reflection of your unique fashion sense. | dana_blair_91609e4d6908cf |
1,886,387 | Import Excel to MySQL, Create Tables Easily with One Click! This SQL Editor is All You Need | Required Tool SQLynx Pro ** (latest version 3.3.0 as of now) Steps SQLynx supports two modes for... | 0 | 2024-06-13T02:51:18 | https://dev.to/concerate/import-excel-to-mysql-create-tables-easily-with-one-click-this-sql-editor-is-all-you-need-3mb7 | **Required Tool**
**SQLynx Pro ** (latest version 3.3.0 as of now)
Steps
SQLynx supports two modes for importing Excel files: when the database has pre-created tables, or when tables need to be created. This guide introduces the process of importing data and creating tables directly when there are no pre-existing tables:
**Step 1**
Open the left navigation tree, find the database where you want to import data, right-click on "Tables" under the object menu, and select "Import to Generate Table" from the menu that appears.
**Step 2**
You can choose to import CSV or Excel formats. Here, we will demonstrate using Excel:
Here, we select the prepared local Excel file to upload. Choose the encoding based on your actual development needs:
Next, you will see the table mapping. On this page, you can modify the name of the imported table, compare source fields with target fields, and adjust field types as needed. For example, I have modified some field types based on actual requirements:
Next, you can see a preview of the table data:
The final step is selecting the import mode. The default setting is to stop on failure, but you can also choose to continue on failure or execute in transactions. When executing in transactions, you can select the batch size for processing the data:
**Step 3**
After executing, check the left navigation pane. If the import is successful, a new table will appear at the target location:
We can right-click on this table and select "View Table Details" to see the detailed table structure. Here, we can further edit the fields, such as creating a primary key, adding comments, and more:
Clicking on the "Data" tab allows you to switch to the page displaying table data. Here, you can see that the data from Excel has been successfully imported into this table.
*Note: The names and other information used in the screenshots are randomly generated virtual data.
Finally, In addition to its user-friendly data import and table creation features, SQLynx excels in handling large-scale data queries, exports, and migrations.
**How to get it? **
http://www.sqlynx.com/en/#/home/probation/SQLynx
| concerate | |
1,882,873 | How to restore Ubuntu desktop UI After an Unexpected tty1 Boot without initial internet access | introduction My Ubuntu 24.04 desktop unexpectedly boot into tty1 presenting a shell... | 0 | 2024-06-13T02:48:40 | https://dev.to/sammybarasa/how-to-restore-ubuntu-desktop-ui-after-an-unexpected-tty1-boot-without-initial-internet-access-2g1j | ## introduction
My Ubuntu 24.04 desktop unexpectedly boot into tty1 presenting a shell interface to interact with on bootup.
The above image shows the tty1 output.
Sometimes this happens when one accidentally removes critical components such as the desktop environment or Python. In my case, I had installed Python while trying to solve other issues I encountered with Python3.
## Step 1: Login to tty1 {tty(n)} with your username and password
First, log in with your username and password to access the system. This way we can run commands and possibly recover the desktop UI.
## Step 2: Confirm you have access to the internet
Once logged in, you have to confirm if you have an internet connection. The easiest way to do this is to run the `ping` command to the internet, and select any address or domain name available.
```sh
ping google.com
```
If you have an internet connection you will receive packets from the address or domain. Therefore you can skip to [step 4](#Step-4--Check-and-repair-packages).
If you cant receive packets, don't worry, we've got you. You can connect to a LAN or move closer to a WLAN connection and proceed to establish a connection to the internet.
## Step 3: Recover an internet connection
In linux, everything can be represented using a file format and this also includes all the network interfaces on the Network Interface Card(NIC). NIC has the ethernet LAN interface and the Wireless LAN (Wi-Fi) interface. These interfaces are stored in the `/sys/class/net` file. so we proceed to list them.
```sh
ls -l /sys/class/net
```
The LAN interface starts with an **e** while the WLAN interface starts with **w**. Note down the interface names.
Connecting the interfaces has several ways.
- use network management interface command`nmtui`
If `nmtui` command is available you can easily get the connection established via the interface that pops up from running running the `nmtui`command.
```sh
nmtui
```
- Modify configs
In somecases `nmtui` is not available and even `netplan` command was not available due to damaged packages and missing packages. As was in my case. Here we have to modify configs. For LAN or wired connection, we can establish a connection without modifying configs while for Wireless connection, we have to modify configs.
You can confirm the state of the link or interfaces whether they are up or down using the `ip a` command
```sh
ip a
```
As highlighted here the ethernet and wireless interfaces might be in down state.
#### wired connection
Connect the LAN cable from your router to the LAN port of your computer
```zsh
sudo ifconfig eth0 up
```
change ***eth0*** to your interface label. The interface will now show up on `ifconfig` command.
If you are using DHCP on your router then
```sh
sudo dhclient eth0
```
The LAN link will obtain an IP address and running simple ping command will return packets from the internet. If you have to assign an IP address you can use the following command.
```sh
ifconfig eth0 192.168.0.1 netmask 255.255.255.0 up
route add default gw GATEWAY-IP eth0
```
If it has worked up to here you can proceed to [step 4](#Step-4--Check-and-repair-packages). If the wired connection hasn't worked, lets try the wireless connection route.
#### wireless connection
For establishing a wireless connection from recovery terminal, checkout the following reference [Reference 1](#my-link), [Reference 2](#my-link2)
<h2 id="Step-4--Check-and-repair-packages"> Step 4: Check and repair packages</h2>
Update packages and that there are no broken packages since we now have an internet connection.
```sh
sudo apt-get update
sudo apt-get upgrade
sudo apt-get --fix-broken install
```
let all these run and install
## Step 5: confirm dgm or dgm3
Confirm the display manager is installed or not
## Step 6: Install ubuntu-desktop
Now reinstall the Ubuntu desktop UI
```sh
sudo apt-get install ubuntu-desktop
```
## Step 7: Install and configure the display manager dgm3
```sh
sudo apt-get install gdm3
```
Properly configure the display manager by running the following command
```sh
sudo dpkg-reconfigure gdm3
```
## Step 8: Reboot
Reboot system to apply changes
```sh
sudo reboot
```
Upon bootup, your Ubuntu UI built on GNOME desktopenvironment should now pop up.
## Conclusion
Thank you. Hope this helps you recover your Ubuntu desktop when the internet connection is not available. When any other issues arise, you can proceed to trouble shoot further. It is important to back up configuration files to avoid loosing initial state during troubleshooting.
### references
1. [Starting network from Ubuntu recovery](https://serverfault.com/questions/21475/starting-network-connection-from-ubuntu-recovery)
2. <a id="my-link" href="https://askubuntu.com/questions/1249160/connecting-to-personal-wifi-on-ubuntu-server-20-04">Wireless connection in ubuntu terminal</a>
3. <a id="my-link2" href="https://linuxconfig.org/ubuntu-20-04-connect-to-wifi-from-command-line">Wireless connection by editing `/etc/netplan/`</a>
4. [Restoring the Ubuntu UI After an Unexpected tty1 Boot](https://medium.com/@elysiumceleste/restoring-the-ubuntu-ui-after-an-unexpected-tty1-boot-9f1042e03139) | sammybarasa | |
1,886,386 | The Ultimate Test Planning Guide: Ensure Software Excellence | In today’s competitive market, your software’s quality can be the deciding factor in its success. A... | 0 | 2024-06-13T02:47:32 | https://dev.to/elle_richard_232/the-ultimate-test-planning-guide-ensure-software-excellence-5bic | softwaredevelopment, testing | In today’s competitive market, your software’s quality can be the deciding factor in its success. A well-designed test plan is your roadmap to excellence. This guide offers the essential steps for creating a test plan that ensures your software functions flawlessly and meets all user expectations.
### What is Test Planning?
Test Planning is a testing construct developed to document the different testing activities needed to deliver a quality product to the end users. A test plan in hand will give you a clear picture of the different areas of focus in the software to ensure it meets all the quality standards set and is ready to go into production.
Test planning also includes a list of all the tasks that must be done promptly to keep track of and ensure the testing is done on time.
**Significance of Test Planning**
Test planning helps teams organize their efforts, allocate resources wisely, and cover all the bases. It also allows transparency across teams. In case there is a new joiner to the team or teams that are external to the quality assurance, they will be able to understand the process and the timelines leading to better processes.
**Different Tools for Test Planning**
As test planning plays a vital role in the testing process, using relevant tools becomes important. Here are some of the tools you can use for Test Planning.
**Spreadsheet software**
Generic tools like Microsoft Excel or Google Sheets work just fine for small applications. Testers can use rows to represent individual test cases and columns to capture information such as test case ID, description, steps to reproduce, expected results, priority, status, and any associated defects. This structured format makes it easy to organize and track test cases throughout the testing process.
If the team is newly formed, they may lack proficiency with specialized test planning tools. In such scenarios, utilizing spreadsheet-based tools can provide a simpler and more effective starting point.
**Test Management Tools**
Tools like JIRA, TestRail, and Zephyr come under this category. They are used to manage and keep track of the testing activities planned for the product. They provide functionalities like Requirement planning, error traceability, dividing tasks into sprints, and many more such capabilities.
**Requirement Gathering Tools**
These tools are used to gather the project requirements together for better understanding and proper documentation. This is crucial to have as the quality assurance standards that you set entirely depend on the depth of requirement understanding you have on the project.
### Components of a Test Plan
Knowing how to create a test plan is important to ensure a smooth testing process. There is a list of things to go about while creating a test plan.
**Set Project Test Objectives:** First, define the testing objective, which means defining the testing goals. This depends on the project requirements captured. It includes all the information about features and functions that are important to the application.
**Test Planning:** Once we have gathered the testing objectives, we need to develop a planning blueprint on the approach and the focus areas of the testing process we will be following. Planning documentation includes the different roles of the teams involving in the development of the project and the timelines set to reach the outcome.
Since it will be a Plan for testing process, the main focus will be on the different team members in the testing team, each of their roles and responsibilities in the testing process, methodologies that will be used, and the timelines set for them to reach test goals.
**Test Environment:** this includes all the testing software, hardware, networking and storage requirements for testing. Test environment intends to ensure all the basic requirements and tools you will need for testing would be satisfied before proceeding with the execution.
**Test Execution Method:** this will list some of the test scripts, manual testing steps and automation testing steps to be followed. This is documented to make the execution easier for the testing and ensure the team is aligned in understanding exactly what needs to be done and why they are executing each of those steps.
**Troubleshooting guide:** it needs to list down all the issues that might occur and the potential solutions to it.
## How to create a test plan
Test planning is a critical phase in the software testing process, as it lays the foundation for a successful testing effort.
**Step 1:** The primary goal of test planning is to define the scope, objectives, approach, resources, and schedule for the testing activities. The procedure of test planning begins with the identification of the testing objectives and scope. In this step, the testing team collaborates with various stakeholders to understand the requirements and expectations of the software application under test. This helps in defining the testing goals, identifying the features to be tested, and setting the boundaries of the testing activities.
**Step 2:** Once the testing objectives and scope are determined, the testing team proceeds to define the test strategy and approach. The test strategy outlines the overall testing approach, including the testing techniques, methods, tools, and resources to be used. The test approach specifies the testing activities to be performed, the sequence in which they will be carried out, and the criteria for test execution and completion.
**Step 3:** After finalizing the test strategy and approach, the testing team creates the test plan, which is a detailed document that describes the testing scope, objectives, schedule, resources, and responsibilities.
The test plan also includes information about the testing environment, test deliverables, risks, and contingency plans. It serves as a roadmap for the testing activities and provides a baseline for monitoring and controlling the testing process.
### Documentation and Communication Protocols for Test Planning
Documenting the steps mentioned above doesn’t work well without properly structuring your Plan document.
Following a standardized template for documenting test plans that include essential details such as objectives, scope, schedule, resources, and responsibilities.
This template is a reference point for all team members and stakeholders involved in the testing process.
Create a repository or database for storing test-related documents, ensuring easy access and version control. This central location enables team members to retrieve relevant information quickly and accurately.
Implement a consistent naming convention and file organization structure to maintain order and facilitate navigation within the documentation repository.
**Communication Protocols:**
Define clear roles and responsibilities for each team member involved in the testing process, outlining their specific duties and expectations regarding communication and collaboration.
Establish regular communication channels, such as team meetings, status updates, and progress reports, to inform all stakeholders about the testing progress, challenges, and achievements.
Utilize project management tools and collaboration platforms to facilitate real-time communication and document sharing among team members, enabling seamless collaboration regardless of geographical locations or time zones.
Implement a feedback mechanism to encourage open communication and constructive feedback among team members, fostering a culture of continuous improvement and shared accountability.
Establish escalation procedures for addressing critical issues or roadblocks that may impede the testing process, ensuring prompt resolution and minimal disruption to project timelines.
### Conclusion
In conclusion, test planning is an important aspect to consider for the software development process that cannot be overlooked. It is the foundation on which the success of a project is built, and it ensures that the product meets the desired quality standards and performs as expected.
**Source:** _This blog was originally published at [Testgrid](https://testgrid.io/blog/test-planning/)._ | elle_richard_232 |
1,886,345 | You don't need `forEach()` | The most basic way to iterate over an array is the forEach method. However often times there is a... | 0 | 2024-06-13T02:46:19 | https://dev.to/read-the-manual/you-dont-need-foreach-1jif | javascript, beginners, webdev, programming | The most basic way to iterate over an array is the `forEach` method. However often times there is a better method for the job. Today we will take a look at common use cases and look at alternative array methods for reaching our goals.
Using `forEach` to solve problems often involves:
- declaring a variable outside of the loop
- modifying that variable inside the loop
When reading the code, this makes the code more difficult to grasp at first glance as you have to set that initial value carefully and then track where that variable is modified. Using specific array methods allows for shorter code that is more expressive and easier to understand and maintain.
## Too Lazy to Read?
If you prefer to watch a video, you can [watch here](https://www.youtube.com/watch?v=jG_Vq1y0lX8) as I go through all these examples in the browser console showing the outputs.
## Creating New Arrays with `map`
Sometimes you need to iterate over an array and create a new array that is based off of the original array. Maybe given a list of people, you need just a list of the full names.
Let us consider this array of the first six presidents of the United States of America.
```js
const presidents = [
{
firstName: "George",
lastName: "Washington",
party: "Independent",
},
{
firstName: "John",
lastName: "Adams",
party: "Federalist",
},
{
firstName: "Thomas",
lastName: "Jefferson",
party: "Democratic-Republican",
},
{
firstName: "James",
lastName: "Madison",
party: "Democratic-Republican",
},
{
firstName: "James",
lastName: "Monroe",
party: "Democratic-Republican",
},
];
```
Solving this with `forEach` looks like so:
```js
const names = [];
presidents.forEach((president) => {
names.push(`${president.firstName} ${president.lastName}`);
});
```
Using `map`, we can accomplish the same thing:
```js
const names = presidents.map(
(president) => `${president.firstName} ${president.lastName}`,
);
```
## Filtering Arrays with `filter`
Another use case is to remove entries that do not meet a certain criteria. From our list of presidents, let's say you only want to see those in the "Democratic-Republican" party.
Solving this with `forEach` looks like:
```js
const drPresidents = [];
presidents.forEach((president) => {
if (president.party === "Democratic-Republican") {
drPresidents.push(president);
}
});
```
Using `filter`, we can accomplish the same thing:
```js
const drPresidents = presidents.filter(
(president) => president.party === "Democratic-Republican",
);
```
## Filtering and Mapping
Another use case is to create a new array from only _some_ of the original elements. Lets continue to consider the list of presidents. Say we wanted a list of the first and last names of presidents in the "Democratic-Republican" party.
Solving this with `forEach` looks like:
```js
const drPresidents = [];
presidents.forEach((president) => {
if (president.party === "Democratic-Republican") {
drPresidents.push(`${president.firstName} ${president.lastName}`);
}
});
```
We can combine the two methods we just reviewed, `map` and `filter` to accomplish the same thing:
```js
const drPresidents = presidents
.filter(president => president.party === "Democratic-Republican");
.map(president => `${president.firstName} ${president.lastName}`)
```
This will iterate over the list _twice_ though, which may not be desirable if you are working with large data sets.
If you want to only go over the array once, you can used `reduce` to accomplish the same thing.
```js
const drPresidents = presidents.reduce((acc, president) => {
if (president.party === "Democratic-Republican") {
acc.push(`${president.firstName} ${president.lastName}`);
}
return acc;
}, []);
```
Alternatively you can also use `flatMap` to get the same result.
```js
const drPresidents = presidents.flatMap((president) =>
president.party === "Democratic-Republican"
? `${president.firstName} ${president.lastName}`
: [],
);
```
This works because `flatMap` will "flatten" the empty array out of the final result.
## Grouping by a Property
Another common use case is to group an array by some property. If we consider our array of presidents, maybe we want to group the presidents by their party. We want an object where the keys are the party names, and the values are the presidents in that party. A final result of:
```js
const presidentsByParty = {
Independent: [
{
firstName: "George",
lastName: "Washington",
party: "Independent",
},
],
Federalist: [
{
firstName: "John",
lastName: "Adams",
party: "Federalist",
},
],
"Democratic-Republican": [
{
firstName: "Thomas",
lastName: "Jefferson",
party: "Democratic-Republican",
},
{
firstName: "James",
lastName: "Madison",
party: "Democratic-Republican",
},
{
firstName: "James",
lastName: "Monroe",
party: "Democratic-Republican",
},
],
};
```
We can achieve this using the `forEach` method like so:
```js
const presidentsByParty = {};
presidents.forEach((president) => {
if (!presidentsByParty[president.party]) {
presidentsByParty[president.party] = [];
}
presidentsByParty[president.party].push(president);
});
```
Avoiding `forEach` you can use `reduce` to achieve the same thing.
```js
const presidentsByParty = presidents.reduce((acc, president) => {
if (!acc[president.party]) {
acc[president.party] = [];
}
acc[president.party].push(president);
return acc;
}, {});
```
Alternatively you can use the `Object.groupBy` method to do this.
```js
const presidentsByParty = Object.groupBy(
presidents,
(president) => president.party,
);
```
## Searching Simple Data Types
Given an array with simple data types _(strings or numbers)_ you might want to see if a certain value is in the array.
```js
const scores = [99, 92, 40, 47, 83, 100, 82];
let hasPerfectScore = false;
scores.forEach((score) => {
if (score === 100) {
hasPerfectScore = true;
}
});
```
This will iterate over every single element in the array, even after it finds a match.
We can use the `.includes` method to do the same and it will stop after finding a match.
```js
const scores = [99, 92, 40, 47, 83, 100, 82];
const hasPerfectScore = scores.includes(100);
```
## Searching Objects
When you use `includes`, you can only use it with simple data types, `string` and `number` being the most common. If you want to compare objects, you will have to use the `some` method.
First lets examine how you would do this with the `forEach` method.
```js
const students = [
{ name: "Adam", score: 99 },
{ name: "Bryan", score: 92 },
{ name: "Calvin", score: 40 },
{ name: "Douglas", score: 47 },
{ name: "Edward", score: 83 },
{ name: "Fred", score: 100 },
{ name: "Georg", score: 82 },
];
let hasPerfectScore = false;
students.forEach((student) => {
if (student.score === 100) {
hasPerfectScore = true;
}
});
```
Using the `some` method we have:
```js
const hasPerfectScore = students.some((student) => student.score === 100);
```
## Checking Every Element
Another use case is checking that all elements meet a certain criteria. For example, you might want to know if every student passed the test. Using `forEach`, you would have:
```js
const MINIMUM_PASSING_SCORE = 60;
let didEveryStudentPass = true;
students.forEach((student) => {
if (student.score < MINIMUM_PASSING_SCORE) {
didEveryStudentPass = false;
}
});
```
As always, `forEach` will go over every element in the array, even after it finds a case where a student did not pass.
Here we can use the `every` method which will stop as soon as one of the elements does not meet the criteria.
```js
const MINIMUM_PASSING_SCORE = 60;
const didEveryStudentPass = students.every(
(student) => student.score >= MINIMUM_PASSING_SCORE,
);
```
## Contrasting `every` and `some`
You can accomplish the same thing using either method by negating the result and negating the condition. For example, the two following are equivalent.
```js
const MINIMUM_PASSING_SCORE = 60;
const didEveryStudentPassEvery = students.every(
(student) => student.score >= MINIMUM_PASSING_SCORE,
);
const didEveryStudentPassSome = !students.some(
(student) => student.score < MINIMUM_PASSING_SCORE,
);
```
Using `some` in the above, can be expressed long-hand form with the following, which is more intuitive to understand.
```js
const didSomeStudentFail = students.some(
(student) => student.score < MINIMUM_PASSING_SCORE,
);
const didEveryStudentPass = !didSomeStudentFail;
```
However, using double negatives is less intuitive and harder to reason about. Using the simpler variation would be preferred.
## Summary
So, though you can use `forEach` to accomplish all these use cases, there are more specific functions that can get the job done as well. There are two benefits to consider to the alternative methods.
1. For use cases where you are searching, using the methods `some`, `every`, `find` and `includes` will be faster as they stop as soon as they find a result.
2. More importantly however is that the intention of the code is more obvious at first glance. You have to study the code less to understand what the goal of it is, which makes maintaining the code a lot easier.
I hope this was helpful and that you learned something new that you can use in your projects!
Do you still think you need to use `forEach`? Let me know in the comments!
| read-the-manual |
1,886,385 | Func Declaration vs Expression vs Statement vs Anonymous vs First Class | Functions in programming are like recipes in cooking. They are sets of instructions that we can reuse... | 27,558 | 2024-06-13T02:41:06 | https://dev.to/imabhinavdev/func-declaration-vs-expression-vs-statement-vs-anonymous-vs-first-class-2ogm | webdev, javascript, beginners, tutorial | Functions in programming are like recipes in cooking. They are sets of instructions that we can reuse whenever we need to perform a specific task. In JavaScript, functions are fundamental building blocks that allow us to organize code and make it reusable.
## Function Declaration
### Definition
Function declarations are a way to create named functions. They start with the keyword `function`, followed by the function name, parameters (if any), and the function body enclosed in curly braces `{}`.
### Example
```javascript
// Function declaration
function greet(name) {
return `Hello, ${name}!`;
}
```
### Explanation
In this example:
- `function` keyword declares a function named `greet`.
- `name` is a parameter that the function expects.
- `{ return ... }` is the function body where the actual code executes.
## Function Expression
### Definition
Function expressions are similar to function declarations but are assigned to variables. They can be named (like below) or anonymous.
### Example
```javascript
// Function expression
const greet = function(name) {
return `Hello, ${name}!`;
};
```
### Explanation
Here:
- `const greet` creates a variable `greet`.
- `function(name) { ... }` is the function expression itself.
- It can be used like `greet("Alice")` to get `"Hello, Alice!"`.
## Function Statement (Hoisting)
### Definition
Function statements, also known as function declarations, are hoisted in JavaScript. This means they are moved to the top of their scope during the compilation phase, allowing them to be used before they are defined in the code.
### Example
```javascript
console.log(greet("Alice")); // Outputs: "Hello, Alice!"
function greet(name) {
return `Hello, ${name}!`;
}
```
### Explanation
Here:
- The function `greet` is called before its definition in the code.
- JavaScript's hoisting moves the function declaration to the top, making it accessible even before its actual placement in the code.
## Anonymous Functions
### Definition
Anonymous functions are functions without a name. They are usually defined inline and are commonly used as arguments to other functions or assigned to variables.
### Example
```javascript
const greet = function(name) {
return `Hello, ${name}!`;
};
console.log(greet("Bob")); // Outputs: "Hello, Bob!"
```
### Explanation
- `function(name) { ... }` is an anonymous function assigned to `const greet`.
- It behaves similarly to named functions but lacks a name for direct referencing.
## First-Class Functions
### Definition
In JavaScript, functions are first-class citizens, meaning they can be:
- Assigned to variables and properties of objects.
- Passed as arguments to other functions.
- Returned from other functions.
### Example
```javascript
function greet(name) {
return `Hello, ${name}!`;
}
const greetFunc = greet;
console.log(greetFunc("Charlie")); // Outputs: "Hello, Charlie!"
```
### Explanation
- `greet` is assigned to `greetFunc`, demonstrating functions as values that can be stored and used just like other data types.
## Conclusion
Understanding the different types of functions in JavaScript—declarations, expressions, statements, anonymous functions, and first-class functions—provides a solid foundation for writing clean, reusable, and efficient code. By mastering these concepts, you empower yourself to create more organized and modular programs. | imabhinavdev |
1,886,381 | Coding Concepts | Analogies are a powerful learning tool because they allow us to understand unfamiliar concepts by... | 0 | 2024-06-13T02:32:25 | https://dev.to/ramdinesh/coding-concepts-4g03 | coding | Analogies are a powerful learning tool because they allow us to understand unfamiliar concepts by relating them to experiences or ideas we already know. Analogies can aid in learning complex concepts in accessible and practical ways.
Learning coding concepts through analogy can be a fun and effective way to understand complex ideas. Here are a few analogies to explain some fundamental coding concepts:
_Variables_
Variables are like containers in a kitchen. Just as containers can hold different types of ingredients, variables can store data values that can be changed and used throughout your code.
_Functions_
Functions are like recipes. They take some ingredients (input), follow a series of steps (the code inside the function), and produce a dish (output). You can use the same recipe to make the dish as many times as you want, just like you can call a function multiple times with different inputs.
_Loops_
Loops are like treadmills. Just as a treadmill allows you to keep running in place until you decide to stop, a loop allows code to execute repeatedly until a particular condition is met.
_Conditional Statements_
Conditional Statements (if/else) are like road signs. They tell the code which direction to go based on certain conditions, much like a road sign directs drivers based on traffic rules.
_Classes and Objects_
Classes and Objects in object-oriented programming are like blueprints and buildings. A class is a blueprint that defines the structure and behaviors, while an object is an actual building constructed from that blueprint.
_Inheritance_
Inheritance is like family traits. Just as children inherit traits from their parents, a class can inherit characteristics and behaviors from another class.
_Arrays_
Arrays are like egg cartons. They hold items in an organized way, allowing you to easily access the item in each slot by its index, just like you can get an egg from a specific spot in the carton.
_Algorithms_
Algorithms are like instructions for assembling furniture. They provide step-by-step directions to accomplish a task and following them correctly ensures the desired outcome.
**_More Concepts to come, Happy Learning!_** | ramdinesh |
1,886,379 | Recursion | This is a submission for DEV Computer Science Challenge v24.06.12: One Byte Explainer. ... | 0 | 2024-06-13T02:32:21 | https://dev.to/ricco1973/recursion-1j68 | devchallenge, cschallenge, computerscience, beginners | _This is a submission for DEV Computer Science Challenge v24.06.12: One Byte Explainer._
## Explainer
Recursion is a programming technique where a function calls itself with a smaller input until it reaches a base case. It's used to solve problems that can be broken down into smaller instances of the same problem. Each recursive call adds a new stack frame, making recursion memory-intensive for large inputs.
## Additional Context
<!-- Please share any additional context you think the judges should take into consideration as it relates to your One Byte Explainer. -->
<!-- Team Submissions: Please pick one member to publish the submission and credit teammates by listing their DEV usernames directly in the body of the post. -->
<!-- Don't forget to add a cover image to your post (if you want). -->
<!-- Thanks for participating! --> | ricco1973 |
1,886,380 | Simple DETR Object Detection with Python | DETR (DEtection TRansformer) is a deep learning model designed for object detection. It utilizes the... | 0 | 2024-06-13T02:32:21 | https://dev.to/chrisalexander0617/simple-detr-object-detection-with-python-539c | ai, machinelearning, python, objectdetection | DETR (DEtection TRansformer) is a deep learning model designed for object detection. It utilizes the Transformer architecture, initially created for natural language processing (NLP) tasks, as its core element to tackle the object detection challenge in an innovative and highly efficient way.
### Prerequisites
I’d assume you have a background in programming with python. If not it should be installed on your computer before continuing.
If you need to download Python, you can visit the official Python downloads page.
[Download Python](https://www.python.org/downloads/)
### Create your virtual environment
Create a virtual environment in python so you can run your packages separate from your host’s environment
`python -m venv myenv`
### Activate virtual environment
**Windows**
`myenv\Scripts\activate`
**Mac**
`source myenv/bin/activate`
### Install packages
We will need to install a few packages before we get started.
```python
pip install transformers torch Pillow requests
```
Next, create an `/images` folder in the root of your project. This is where you will save your images to test your AI solution. Im using .jpg files from www.unsplash.com.
After saving an image into the /images directory, we can now start to write the code that will find our image and pass it into the `Image.open()` method.
```python
import os
from transformers import DetrImageProcessor, DetrForObjectDetection
import torch
from PIL import Image
print("transformers", DetrImageProcessor)
current_dir = os.path.dirname(os.path.abspath(__file__))
images_dir = os.path.abspath(os.path.join(current_dir, 'images'))
print("Root directory:", images_dir)
image_path = os.path.join(images_dir, 'airplane.jpg') #
print("image path:", image_path)
print("Reading images from /images")
image = Image.open(image_path)
print("Processing image...")
```
Once this runs with no errors, we can confidently add the rest of our solution which will scan and provide the results of our image detection.
```python
processor = DetrImageProcessor.from_pretrained("facebook/detr-resnet-50", revision="no_timm")
model = DetrForObjectDetection.from_pretrained("facebook/detr-resnet-50", revision="no_timm")
inputs = processor(images=image, return_tensors="pt")
outputs = model(**inputs)
target_sizes = torch.tensor([image.size[::-1]])
results = processor.post_process_object_detection(outputs, target_sizes=target_sizes, threshold=0.9)[0]
for score, label, box in zip(results["scores"], results["labels"], results["boxes"]):
box = [round(i, 2) for i in box.tolist()]
print(
f"Detected {model.config.id2label[label.item()]} with confidence "
f"{round(score.item(), 3)} at location {box}"
)
```
After running server.py, you should get an output similar to this. The decimal numbers you see after `location` are the coordinates of the area in your image that your model detected the object at.
```python
Reading images from /images
Processing image...
Detected bird with confidence 0.992 at location [55.82, 32.17, 225.04, 225.28]
```
## Potential business value
Models like this can provide a lot of value to software services and products people interact with daily.
Image detection models can detect things like cancer in clinical trials, assist autonomous vehicles with identifying red light and emergency signals or even prevent unauthorized access to systems and physical resources by detecting the identity of a user.
Possibilities are endless.
[Connect with me on LinkedIn](https://www.linkedin.com/in/christopher-clemmons)
### | chrisalexander0617 |
1,886,376 | Market quotes collector upgrade again | Supporting CSV format file import to provide custom data source Recently, a trader needs... | 0 | 2024-06-13T02:24:08 | https://dev.to/fmzquant/market-quotes-collector-upgrade-again-2f07 | market, trading, cryptocurrency, fmzquant | ## Supporting CSV format file import to provide custom data source
Recently, a trader needs to use his own CSV format file as a data source for FMZ platform backtest system. our platform's backtest system has many functions and is simple and efficient to use, so that as long as users have their own data, they can perform backtesting according to these data, which is no longer limited to the exchanges and varieties supported by our platform data center.
## Design ideas
The design idea is actually very simple. We only need to change it slightly based on the previous market collector. We add a parameter isOnlySupportCSV to the market collector to control whether only the CSV file is used as the data source for the backtest system. The parameter filePathForCSV is used to set the path of the CSV data file placed on the server where the market collector robot runs. At last, it is based on whether the isOnlySupportCSV parameter is set to True to decide which data source to use (collected by yourself or the data in the CSV file), this change is mainly in the do_GET function of the Provider class.
## What is a CSV file?
Comma-separated values, also known as CSV, sometimes referred to as character-separated values, because the separator character can also not be a comma. Its file stores the table data (numbers and text) in plain text. Plain text means that the file is a sequence of characters and contains no data that must be interpreted like a binary number. The CSV file consists of any number of records, separated by some newline character; each record is composed of fields, and the separators between fields are other characters or strings, and the most common are commas or tabs. Generally, all records have the exact same sequence of fields. They are usually plain text files. It is recommended to use WORDPAD or Excel to open.
The general standard of the CSV file format does not exist, but there are certain rules, generally one record per line, and the first line is the header. The data in each row is separated by commas.
For example, the CSV file we used for testing is opened with Notepad like this:
Observed that the first line of the CSV file is the table header.
```
,open,high,low,close,vol
```
We just need to parse and sort out these data, and then construct it into the format required by the custom data source of the backtest system. This code in our previous article has already been processed, and only needs to be modified slightly.
## Modified code
```
import _thread
import pymongo
import json
import math
import csv
from http.server import HTTPServer, BaseHTTPRequestHandler
from urllib.parse import parse_qs, urlparse
def url2Dict(url):
query = urlparse(url).query
params = parse_qs(query)
result = {key: params[key][0] for key in params}
return result
class Provider(BaseHTTPRequestHandler):
def do_GET(self):
global isOnlySupportCSV, filePathForCSV
try:
self.send_response(200)
self.send_header("Content-type", "application/json")
self.end_headers()
dictParam = url2Dict(self.path)
Log("The custom data source service receives the request，self.path:", self.path, "query parameter：", dictParam)
# At present, the backtest system can only select the exchange name from the list. When adding a custom data source, set it to Binance, that is: Binance
exName = exchange.GetName()
# Note that period is the bottom K-line period
tabName = "%s_%s" % ("records", int(int(dictParam["period"]) / 1000))
priceRatio = math.pow(10, int(dictParam["round"]))
amountRatio = math.pow(10, int(dictParam["vround"]))
fromTS = int(dictParam["from"]) * int(1000)
toTS = int(dictParam["to"]) * int(1000)
# Request data
data = {
"schema" : ["time", "open", "high", "low", "close", "vol"],
"data" : []
}
if isOnlySupportCSV:
# Handle CSV reading, filePathForCSV path
listDataSequence = []
with open(filePathForCSV, "r") as f:
reader = csv.reader(f)
# Get table header
header = next(reader)
headerIsNoneCount = 0
if len(header) != len(data["schema"]):
Log("The CSV file format is wrong, the number of columns is different, please check!", "#FF0000")
return
for ele in header:
for i in range(len(data["schema"])):
if data["schema"][i] == ele or ele == "":
if ele == "":
headerIsNoneCount += 1
if headerIsNoneCount > 1:
Log("The CSV file format is incorrect, please check!", "#FF0000")
return
listDataSequence.append(i)
break
# Read content
while True:
record = next(reader, -1)
if record == -1:
break
index = 0
arr = [0, 0, 0, 0, 0, 0]
for ele in record:
arr[listDataSequence[index]] = int(ele) if listDataSequence[index] == 0 else (int(float(ele) * amountRatio) if listDataSequence[index] == 5 else int(float(ele) * priceRatio))
index += 1
data["data"].append(arr)
Log("data: ", data, "Respond to backtest system requests.")
self.wfile.write(json.dumps(data).encode())
return
# Connect to the database
Log("Connect to the database service to obtain data, the database: ", exName, "table: ", tabName)
myDBClient = pymongo.MongoClient("mongodb://localhost:27017")
ex_DB = myDBClient[exName]
exRecords = ex_DB[tabName]
# Construct query conditions: greater than a certain value {'age': {'$ gt': 20}} less than a certain value {'age': {'$lt': 20}}
dbQuery = {"$and":[{'Time': {'$gt': fromTS}}, {'Time': {'$lt': toTS}}]}
Log("Query conditions: ", dbQuery, "Number of inquiries: ", exRecords.find(dbQuery).count(), "Total number of databases: ", exRecords.find().count())
for x in exRecords.find(dbQuery).sort("Time"):
# Need to process data accuracy according to request parameters round and vround
bar = [x["Time"], int(x["Open"] * priceRatio), int(x["High"] * priceRatio), int(x["Low"] * priceRatio), int(x["Close"] * priceRatio), int(x["Volume"] * amountRatio)]
data["data"].append(bar)
Log("data: ", data, "Respond to backtest system requests.")
# Write data response
self.wfile.write(json.dumps(data).encode())
except BaseException as e:
Log("Provider do_GET error, e:", e)
def createServer(host):
try:
server = HTTPServer(host, Provider)
Log("Starting server, listen at: %s:%s" % host)
server.serve_forever()
except BaseException as e:
Log("createServer error, e:", e)
raise Exception("stop")
def main():
LogReset(1)
if (isOnlySupportCSV):
try:
# _thread.start_new_thread(createServer, (("localhost", 9090), )) # local test
_thread.start_new_thread(createServer, (("0.0.0.0", 9090), )) # Test on VPS server
Log("Start the custom data source service thread, and the data is provided by the CSV file. ", "#FF0000")
except BaseException as e:
Log("Failed to start the custom data source service!")
Log("Error message: ", e)
raise Exception("stop")
while True:
LogStatus(_D(), "Only start the custom data source service, do not collect data!")
Sleep(2000)
exName = exchange.GetName()
period = exchange.GetPeriod()
Log("collect", exName, "Exchange K-line data,", "K line cycle:", period, "Second")
# Connect to the database service, service address mongodb: //127.0.0.1: 27017 See the settings of mongodb installed on the server
Log("Connect to the mongodb service of the hosting device, mongodb://localhost:27017")
myDBClient = pymongo.MongoClient("mongodb://localhost:27017")
# Create a database
ex_DB = myDBClient[exName]
# Print the current database table
collist = ex_DB.list_collection_names()
Log("mongodb", exName, "collist:", collist)
# Check if the table is deleted
arrDropNames = json.loads(dropNames)
if isinstance(arrDropNames, list):
for i in range(len(arrDropNames)):
dropName = arrDropNames[i]
if isinstance(dropName, str):
if not dropName in collist:
continue
tab = ex_DB[dropName]
Log("dropName:", dropName, "delete:", dropName)
ret = tab.drop()
collist = ex_DB.list_collection_names()
if dropName in collist:
Log(dropName, "failed to delete")
else :
Log(dropName, "successfully deleted")
# Start a thread to provide a custom data source service
try:
# _thread.start_new_thread(createServer, (("localhost", 9090), )) # local test
_thread.start_new_thread(createServer, (("0.0.0.0", 9090), )) # Test on VPS server
Log("Open the custom data source service thread", "#FF0000")
except BaseException as e:
Log("Failed to start the custom data source service!")
Log("Error message:", e)
raise Exception("stop")
# Create the records table
ex_DB_Records = ex_DB["%s_%d" % ("records", period)]
Log("Start collecting", exName, "K-line data", "cycle:", period, "Open (create) the database table:", "%s_%d" % ("records", period), "#FF0000")
preBarTime = 0
index = 1
while True:
r = _C(exchange.GetRecords)
if len(r) < 2:
Sleep(1000)
continue
if preBarTime == 0:
# Write all BAR data for the first time
for i in range(len(r) - 1):
bar = r[i]
# Write root by root, you need to determine whether the data already exists in the current database table, based on timestamp detection, if there is the data, then skip, if not write
retQuery = ex_DB_Records.find({"Time": bar["Time"]})
if retQuery.count() > 0:
continue
# Write bar to the database table
ex_DB_Records.insert_one({"High": bar["High"], "Low": bar["Low"], "Open": bar["Open"], "Close": bar["Close"], "Time": bar["Time"], "Volume": bar["Volume"]})
index += 1
preBarTime = r[-1]["Time"]
elif preBarTime != r[-1]["Time"]:
bar = r[-2]
# Check before writing data, whether the data already exists, based on time stamp detection
retQuery = ex_DB_Records.find({"Time": bar["Time"]})
if retQuery.count() > 0:
continue
ex_DB_Records.insert_one({"High": bar["High"], "Low": bar["Low"], "Open": bar["Open"], "Close": bar["Close"], "Time": bar["Time"], "Volume": bar["Volume"]})
index += 1
preBarTime = r[-1]["Time"]
LogStatus(_D(), "preBarTime:", preBarTime, "_D(preBarTime):", _D(preBarTime/1000), "index:", index)
# Increase drawing display
ext.PlotRecords(r, "%s_%d" % ("records", period))
Sleep(10000)
```
## Run test
First, we start the market collector robot. We add an exchange to the robot and let the robot run.
Parameter configuration:
Then we create a test strategy:
```
function main() {
Log(exchange.GetRecords())
Log(exchange.GetRecords())
Log(exchange.GetRecords())
}
```
The strategy is very simple, only obtain and print K-line data three times.
On backtest page, set the data source of the backtest system as a custom data source, and fill in the address of the server where the market collector robot runs. Since the data in our CSV file is a 1-minute K line. So when backtest, we set the K-line period to 1 minute.
Click to start the backtest, and the market collector robot receives the data request:
After the execution strategy of the backtest system is completed, a K-line chart is generated based on the K-line data in the data source.
Compare the data in the file:
From: https://blog.mathquant.com/2020/05/26/market-quotes-collector-upgrade-again.html | fmzquant |
1,886,375 | Alternatives to npm: Exploring Different Package Managers for JavaScript Development | When it comes to managing dependencies in JavaScript projects, npm (Node Package Manager) is often... | 0 | 2024-06-13T02:20:38 | https://dev.to/vyan/alternatives-to-npm-exploring-different-package-managers-for-javascript-development-1h7g | webdev, javascript, beginners, npm | When it comes to managing dependencies in JavaScript projects, npm (Node Package Manager) is often the go-to choice. However, several other package managers can offer different features and benefits that might better suit your specific needs. In this blog, we will explore some popular alternatives to npm, including Yarn, pnpm, Bun, and others, to help you make an informed decision on which package manager to use for your next project.
## 1. Yarn
### Overview
Yarn is a package manager created by Facebook to address some of the shortcomings of npm. It offers improvements in speed, security, and reliability.
### Features
- **Fast Installations:** Yarn is known for its parallel installation process, which significantly speeds up the installation of packages.
- **Offline Mode:** Yarn caches every package it downloads, so you don’t need to hit the network next time you need it.
- **Deterministic Dependency Resolution:** Yarn uses a lockfile to ensure that dependencies are installed consistently across different environments.
- **Enhanced Security:** Yarn verifies the integrity of every installed package using checksums.
### Installation
You can install Yarn globally using npm:
```bash
npm install -g yarn
```
## 2. pnpm
### Overview
pnpm is a fast, disk space-efficient package manager. It uses a content-addressable file system to store all files in a single place on the disk, which means all projects share the same set of packages.
### Features
- **Efficient Storage:** pnpm saves a lot of disk space and reduces the time required for installation.
- **Fast:** pnpm is generally faster than npm and Yarn, especially for projects with a large number of dependencies.
- **Strict Dependency Management:** pnpm ensures that a project only has access to the packages it explicitly depends on.
### Installation
You can install pnpm globally using npm:
```bash
npm install -g pnpm
```
## 3. Bun
### Overview
Bun is a modern JavaScript runtime that includes a fast, native package manager. It aims to be a drop-in replacement for Node.js, npm, and Yarn, offering significant performance improvements.
### Features
- **High Performance:** Bun is built in Zig and focuses on speed, providing faster package installations and runtime performance.
- **Native Module Support:** Bun has built-in support for npm packages and Node.js APIs, making it easy to migrate existing projects.
- **Tooling Included:** Bun includes a fast bundler, transpiler, and task runner, reducing the need for additional tools.
### Installation
You can install Bun using the following command:
```bash
curl -fsSL https://bun.sh/install | bash
```
## 4. npm 7 and Beyond
### Overview
While npm itself is often critiqued, its latest versions have introduced several new features that address many of the concerns users have had with older versions.
### Features
- **Workspaces:** npm 7 introduced support for workspaces, which makes it easier to manage monorepos.
- **Improved Dependency Resolution:** npm 7 and later versions have improved the way dependencies are resolved, making the process faster and more reliable.
- **Automatic Peer Dependency Installation:** npm 7 automatically installs peer dependencies, which simplifies the management of complex dependency trees.
### Installation
To update to the latest version of npm:
```bash
npm install -g npm@latest
```
## 5. Bower (Deprecated)
### Overview
Bower was a popular package manager for front-end dependencies. While it’s now deprecated in favor of modern tools like Yarn and npm, it’s still worth mentioning for historical context.
### Features
- **Front-End Focused:** Bower was designed to manage front-end dependencies, which made it popular in its time.
- **Flat Dependency Tree:** Bower installs dependencies in a flat tree, which can reduce conflicts.
### Alternatives
For managing front-end dependencies, it’s recommended to use npm or Yarn with tools like Webpack or Parcel.
## 6. jspm
### Overview
jspm is a package manager for JavaScript that allows you to load any module format (including ES modules) directly from the npm registry or GitHub.
### Features
- **ES Module Support:** jspm supports modern ES modules out of the box.
- **Dynamic Loading:** It allows for dynamic loading of modules in the browser.
- **Tree Shaking:** jspm can optimize the delivery of your modules with tree shaking.
### Installation
You can install jspm globally using npm:
```bash
npm install -g jspm
```
## 7. Deno
### Overview
Deno is a new runtime for JavaScript and TypeScript that has a built-in package manager and offers an alternative to npm by handling packages differently.
### Features
- **Built-In Module System:** Deno uses ES modules and URLs to directly import dependencies.
- **Security:** Deno runs in a secure sandbox by default, requiring explicit permission for file, network, and environment access.
- **TypeScript Support:** Deno has first-class support for TypeScript without requiring additional tooling.
### Installation
You can install Deno by following the instructions on its [official website](https://deno.land/).
## Conclusion
While npm is a powerful and widely-used package manager, alternatives like Yarn, pnpm, Bun, jspm, and even newer runtimes like Deno offer unique features and improvements. Depending on your project requirements and preferences, exploring these options can enhance your development workflow. Whether you prioritize speed, efficient storage, or modern module support, there’s a package manager out there that can meet your needs. | vyan |
1,886,361 | Real vs Fake Jordan 4: Key Differences | The Jordan 4 is an iconic sneaker that often falls prey to counterfeiters. Identifying the... | 0 | 2024-06-13T02:14:46 | https://dev.to/dana_blair_91609e4d6908cf/real-vs-fake-jordan-4-key-differences-33pd | The Jordan 4 is an iconic sneaker that often falls prey to counterfeiters. Identifying the differences between real and [fake Jordan 4](https://www.colareps.com/collections/replica-air-jordan-4/)s is crucial for any collector or enthusiast. Here, we provide a detailed guide on how to distinguish authentic pairs from their counterfeit counterparts.
## Stitching Quality
One of the most telling signs of authenticity is the stitching. Authentic Jordan 4s feature:
Consistent stitching: Uniform and tight with no loose threads.
Pattern accuracy: The stitching pattern on the toe box, sides, and heel should be symmetrical and precise.
In contrast, fake Jordan 4s often exhibit:
Irregular stitching: Uneven and loose threads.
Inconsistent patterns: Misaligned stitching and irregular spacing.
## Material Examination
Upper Materials
Authentic Jordan 4s are made from high-quality materials such as leather or nubuck. Key aspects to check include:
Texture and feel: The material should feel premium and consistent throughout the shoe.
Durability: Genuine materials are more resilient and less prone to wear.
Fake Jordan 4s often use cheaper materials that:
Feel plasticky: Inferior quality with a synthetic feel.
Show signs of wear quickly: Less durable and more prone to damage.
## Sole and Midsole
The soles of authentic Jordan 4s are made from durable, flexible rubber. Look for:
Resilience: The rubber should bounce back when pressed.
Detailed patterns: Authentic pairs have well-defined sole patterns.
Counterfeit versions typically feature:
Stiff rubber: Less flexible and more rigid.
Blurry patterns: Poorly defined and inconsistent patterns.
## Logo Details
Jumpman Logo
The Jumpman logo is a critical authenticity marker. Authentic pairs have:
Accurate proportions: The arms, legs, and torso of the Jumpman should be balanced.
Sharp details: Clear and precise stitching or printing.
Fake pairs often display:
Distorted proportions: Misaligned arms, legs, or torso.
Blurry details: Poor stitching quality leading to unclear logos.
## Heel Logo
For models with the Nike Air logo on the heel, ensure:
Correct font and spacing: The font should match Nike's official design.
Proper alignment: The logo should be centered and straight.
Counterfeit pairs may show:
Incorrect font: Deviations from the official Nike font.
Misalignment: Tilted or off-center logos.
## Tongue Tag Examination
The tongue tag on authentic Jordan 4s features high-quality embroidery. Key elements include:
Clear Jumpman logo: Proportional and well-defined.
"Flight" text: Evenly spaced and sharply stitched.
Fake Jordan 4s often have:
Blurry logos: Poor embroidery quality.
Uneven text: Misaligned and irregular "Flight" text.
## Box and Packaging
Authentic Jordan 4s come in high-quality boxes with:
Sharp printing: Clear text and logos.
Accurate labels: Product codes that match the ones on the shoes.
Counterfeit boxes usually show:
Blurry printing: Poor quality text and logos.
Incorrect labels: Mismatched product codes or details.
## Price and Source
Always consider the price and seller's reputation. Authentic Jordan 4s are rarely sold at significantly lower prices than the market average. Buying from reputable retailers or verified sellers can minimize the risk of purchasing counterfeits.
By closely examining these aspects, you can effectively differentiate between real and fake Jordan 4s, ensuring that your collection remains genuine and valuable. | dana_blair_91609e4d6908cf | |
1,886,360 | 中国区使用Docker官方镜像（非国内加速）Use official Docker images in China (not domestic acceleration) | 写在前面： Foreword: 1、本文使用中英语言，英文为机翻 1、This article is written in both Chinese and English. The English... | 0 | 2024-06-13T02:10:24 | https://dev.to/aionerljjj/zhong-guo-qu-shi-yong-dockerguan-fang-jing-xiang-fei-guo-nei-jia-su-use-official-docker-images-in-china-not-domestic-acceleration-2i4p | docker, vpn | 写在前面：
Foreword:
1、本文使用中英语言，英文为机翻
1、This article is written in both Chinese and English. The English version is machine-translated.
2、实测可用，完整复制命令即可使用，如有问题，请邮件至aionerljj@gmail.com
2、The instructions have been tested and are functional. Simply copy and use the commands as they are. If you encounter any issues, please email aionerljj@gmail.com.
正式开始：
Let's get started:
本人使用供应商提供的机场，该机场无梯子也能访问
I am using a service provided by a supplier. This service can be accessed without a VPN.
机场官方链接：{% embed https://w1.v2free.cc/auth/register?code=oZhk %}.
Official VPN Service Link: {% embed https://w1.v2free.cc/auth/register?code=oZhk %}.
1、机场注册账号：
1、Register for a VPN Service Account:
机场页面为中文，暂未查看到英文切换选项，如需使用英文请自备翻译工具
The VPN service page is in Chinese, and there is currently no option to switch to English. Please use a translation tool if you need English.
1.1 进入链接可见以下内容：
1.1 After entering the link, you will see the following content:
1.2 点击右上角注册按钮，可见以下内容
1.2 Click on the register button in the upper right corner to see the following content.
**注意**：邮箱使用个人真实邮箱（不是第三方登录/注册）作为收受邮件的验证邮箱
密码自定
**Note**: Use your personal email (not a third-party login/registration) as the verification email for receiving messages.
Password can be set as desired.
1.3 注册登录成功
1.3 Successful registration and login
可见用户中心页面，下面进行介绍基本使用：
You will see the user center page. Below is an introduction to basic usage:
1.3.1 免费用户初始赠送1024MB流量，其他流量需登录签到，签到有时需要验证是否为真人
1.3.1 Free users initially receive 1024MB of data. Additional data can be obtained by logging in and checking in, which sometimes requires verification to confirm you are a real person.
1.3.2 免费用户注意不要找客服，可能存在封号的可能
1.3.2 Free users should avoid contacting customer service, as it may result in account suspension.
1.3.3 下方有各个系统的梯子上网使用教程
1.3.3 Below, you will find tutorials for using the VPN service on various systems.
**本人要讲的是Linux 中使用Clash**
**I will explain how to use Clash on Linux.**
根据供应商说法：Linux版访问中国网站不走代理，访问其他国家和地区的网站走代理
According to the supplier: The Linux version does not use a proxy when accessing Chinese websites, but uses a proxy for websites in other countries and regions.
2、上网前准备：
Preparation Before Going Online:
2.1 按顺序点击：Linux - Clash for linux 教程 进入该文档教程页面
2.1 Click in the following order: Linux - Clash for Linux Tutorial to enter the tutorial page.
**注意**：部分内容无法查看，请登录后再查看，因该教程提供针对每个用户的特定链接，而非共性链接
**Note**: Some content may not be viewable. Please log in to view it, as this tutorial provides specific links for each user rather than a common link.
教程页面链接：
Tutorial page link:
{% embed https://v2free.net/doc/#/linux/clash %}.
页面部分内容截图如下：
A screenshot of part of the page content is shown below:
请按照教程，百分百的按照其内容配置
A screenshot of part of the page content is shown below
2.2 唯有不同之处：
2.2 The only difference:
有内容如下：
There is content as follows:
在这里我们进行简单修改，不按照它的配置：
Here we will make a simple modification, not following its configuration:
进入你的 /root 目录，并编辑文件： .bashrc 文件，这里我使用的是vim工具
Go to your /root directory and edit the .bashrc file. I am using the vim tool for this.
```
cd /root
vim .bashrc
```
按键： 英文 I
Press: English I
编写配置如下：
Write the following configuration:
完成后使配置立即生效：
After completion, make the configuration take effect immediately:
```
source .bashrc
```
使用以下命令验证是否生效：
Use the following command to verify if it is effective:
```
echo $http_proxy
echo $https_proxy
```
这里是将在命令行设置的命令，使用在全局环境中
This is a command set in the command line, used in the global environment.
2.3 完整配置完成以后，请使用命令检测：
2.3 After completing the full configuration, please use the command to check:
```
curl -I www.google.com
```
稍等一会，如显示内容如下：
Wait a moment, if the following content is displayed:
```
:~/.config/mihomo# curl -I www.google.com
HTTP/1.1 200 OK
Transfer-Encoding: chunked
......
```
即为可以访问，下面开始配置Docker的代理
It means you can access the internet. Now let's start configuring the Docker proxy.
3、Docker代理配置
3、Docker Proxy Configuration
进入目录：
Navigate to the directory:
```
cd /etc/systemd/system/
```
创建目录并进入：
Create a directory and enter it:
```
docker.service.d
cd docker.service.d
```
vim 创建文件编写内容：
Use vim to create a file and write the content:
```
vim http-proxy.conf
i
[Service]
Environment="HTTP_PROXY=http://127.0.0.1:7890"
shift + :
wq
vim https-proxy.conf
i
[Service]
Environment="HTTPS_PROXY=http://127.0.0.1:7890"
shift + :
wq
```
使用命令如下：
The commands are as follows:
```
sudo systemctl daemon-reload
sudo systemctl restart docker
```
之后命令：
Afterwards, run the command:
```
sudo systemctl show --property=Environment docker
```
确认输出包含 HTTP-PROXY和HTTPS-PROXY
Ensure the output includes HTTP-PROXY and HTTPS-PROXY.
成功后使用命令：
After successful configuration, use the command:
```
docker run busybox wget -O- http://www.google.com
```
完整正确结果如下：
The complete correct result should look like this:
注意：wget 提示can`t是正常情况无需在意
Note: If wget shows a "can't" message, it is normal and can be ignored.
至此，Docker无需国内镜像源即可访问docker 官网
At this point, Docker can access the Docker official website without using domestic mirror sources.
| aionerljjj |
1,886,359 | 中国区使用Docker官方镜像（非国内加速）Use official Docker images in China (not domestic acceleration) | 写在前面： Foreword: 1、本文使用中英语言，英文为机翻 1、This article is written in both Chinese and English. The English... | 0 | 2024-06-13T02:10:24 | https://dev.to/aionerljjj/zhong-guo-qu-shi-yong-dockerguan-fang-jing-xiang-fei-guo-nei-jia-su-use-official-docker-images-in-china-not-domestic-acceleration-5hfd | docker, vpn | 写在前面：
Foreword:
1、本文使用中英语言，英文为机翻
1、This article is written in both Chinese and English. The English version is machine-translated.
2、实测可用，完整复制命令即可使用，如有问题，请邮件至aionerljj@gmail.com
2、The instructions have been tested and are functional. Simply copy and use the commands as they are. If you encounter any issues, please email aionerljj@gmail.com.
正式开始：
Let's get started:
本人使用供应商提供的机场，该机场无梯子也能访问
I am using a service provided by a supplier. This service can be accessed without a VPN.
机场官方链接：{% embed https://w1.v2free.cc/auth/register?code=oZhk %}.
Official VPN Service Link: {% embed https://w1.v2free.cc/auth/register?code=oZhk %}.
1、机场注册账号：
1、Register for a VPN Service Account:
机场页面为中文，暂未查看到英文切换选项，如需使用英文请自备翻译工具
The VPN service page is in Chinese, and there is currently no option to switch to English. Please use a translation tool if you need English.
1.1 进入链接可见以下内容：
1.1 After entering the link, you will see the following content:
1.2 点击右上角注册按钮，可见以下内容
1.2 Click on the register button in the upper right corner to see the following content.
**注意**：邮箱使用个人真实邮箱（不是第三方登录/注册）作为收受邮件的验证邮箱
密码自定
**Note**: Use your personal email (not a third-party login/registration) as the verification email for receiving messages.
Password can be set as desired.
1.3 注册登录成功
1.3 Successful registration and login
可见用户中心页面，下面进行介绍基本使用：
You will see the user center page. Below is an introduction to basic usage:
1.3.1 免费用户初始赠送1024MB流量，其他流量需登录签到，签到有时需要验证是否为真人
1.3.1 Free users initially receive 1024MB of data. Additional data can be obtained by logging in and checking in, which sometimes requires verification to confirm you are a real person.
1.3.2 免费用户注意不要找客服，可能存在封号的可能
1.3.2 Free users should avoid contacting customer service, as it may result in account suspension.
1.3.3 下方有各个系统的梯子上网使用教程
1.3.3 Below, you will find tutorials for using the VPN service on various systems.
**本人要讲的是Linux 中使用Clash**
**I will explain how to use Clash on Linux.**
根据供应商说法：Linux版访问中国网站不走代理，访问其他国家和地区的网站走代理
According to the supplier: The Linux version does not use a proxy when accessing Chinese websites, but uses a proxy for websites in other countries and regions.
2、上网前准备：
Preparation Before Going Online:
2.1 按顺序点击：Linux - Clash for linux 教程 进入该文档教程页面
2.1 Click in the following order: Linux - Clash for Linux Tutorial to enter the tutorial page.
**注意**：部分内容无法查看，请登录后再查看，因该教程提供针对每个用户的特定链接，而非共性链接
**Note**: Some content may not be viewable. Please log in to view it, as this tutorial provides specific links for each user rather than a common link.
教程页面链接：
Tutorial page link:
{% embed https://v2free.net/doc/#/linux/clash %}.
页面部分内容截图如下：
A screenshot of part of the page content is shown below:
请按照教程，百分百的按照其内容配置
A screenshot of part of the page content is shown below
2.2 唯有不同之处：
2.2 The only difference:
有内容如下：
There is content as follows:
在这里我们进行简单修改，不按照它的配置：
Here we will make a simple modification, not following its configuration:
进入你的 /root 目录，并编辑文件： .bashrc 文件，这里我使用的是vim工具
Go to your /root directory and edit the .bashrc file. I am using the vim tool for this.
```
cd /root
vim .bashrc
```
按键： 英文 I
Press: English I
编写配置如下：
Write the following configuration:
完成后使配置立即生效：
After completion, make the configuration take effect immediately:
```
source .bashrc
```
使用以下命令验证是否生效：
Use the following command to verify if it is effective:
```
echo $http_proxy
echo $https_proxy
```
这里是将在命令行设置的命令，使用在全局环境中
This is a command set in the command line, used in the global environment.
2.3 完整配置完成以后，请使用命令检测：
2.3 After completing the full configuration, please use the command to check:
```
curl -I www.google.com
```
稍等一会，如显示内容如下：
Wait a moment, if the following content is displayed:
```
:~/.config/mihomo# curl -I www.google.com
HTTP/1.1 200 OK
Transfer-Encoding: chunked
......
```
即为可以访问，下面开始配置Docker的代理
It means you can access the internet. Now let's start configuring the Docker proxy.
3、Docker代理配置
3、Docker Proxy Configuration
进入目录：
Navigate to the directory:
```
cd /etc/systemd/system/
```
创建目录并进入：
Create a directory and enter it:
```
docker.service.d
cd docker.service.d
```
vim 创建文件编写内容：
Use vim to create a file and write the content:
```
vim http-proxy.conf
i
[Service]
Environment="HTTP_PROXY=http://127.0.0.1:7890"
shift + :
wq
vim https-proxy.conf
i
[Service]
Environment="HTTPS_PROXY=http://127.0.0.1:7890"
shift + :
wq
```
使用命令如下：
The commands are as follows:
```
sudo systemctl daemon-reload
sudo systemctl restart docker
```
之后命令：
Afterwards, run the command:
```
sudo systemctl show --property=Environment docker
```
确认输出包含 HTTP-PROXY和HTTPS-PROXY
Ensure the output includes HTTP-PROXY and HTTPS-PROXY.
成功后使用命令：
After successful configuration, use the command:
```
docker run busybox wget -O- http://www.google.com
```
完整正确结果如下：
The complete correct result should look like this:
注意：wget 提示can`t是正常情况无需在意
Note: If wget shows a "can't" message, it is normal and can be ignored.
至此，Docker无需国内镜像源即可访问docker 官网
At this point, Docker can access the Docker official website without using domestic mirror sources.
| aionerljjj |
1,886,358 | 中国区使用Docker官方镜像（非国内加速）Use official Docker images in China (not domestic acceleration) | 写在前面： Foreword: 1、本文使用中英语言，英文为机翻 1、This article is written in both Chinese and English. The English... | 0 | 2024-06-13T02:10:24 | https://dev.to/aionerljjj/zhong-guo-qu-shi-yong-dockerguan-fang-jing-xiang-fei-guo-nei-jia-su-use-official-docker-images-in-china-not-domestic-acceleration-4fjf | docker, vpn | 写在前面：
Foreword:
1、本文使用中英语言，英文为机翻
1、This article is written in both Chinese and English. The English version is machine-translated.
2、实测可用，完整复制命令即可使用，如有问题，请邮件至aionerljj@gmail.com
2、The instructions have been tested and are functional. Simply copy and use the commands as they are. If you encounter any issues, please email aionerljj@gmail.com.
正式开始：
Let's get started:
本人使用供应商提供的机场，该机场无梯子也能访问
I am using a service provided by a supplier. This service can be accessed without a VPN.
机场官方链接：{% embed https://w1.v2free.cc/auth/register?code=oZhk %}.
Official VPN Service Link: {% embed https://w1.v2free.cc/auth/register?code=oZhk %}.
1、机场注册账号：
1、Register for a VPN Service Account:
机场页面为中文，暂未查看到英文切换选项，如需使用英文请自备翻译工具
The VPN service page is in Chinese, and there is currently no option to switch to English. Please use a translation tool if you need English.
1.1 进入链接可见以下内容：
1.1 After entering the link, you will see the following content:
1.2 点击右上角注册按钮，可见以下内容
1.2 Click on the register button in the upper right corner to see the following content.
**注意**：邮箱使用个人真实邮箱（不是第三方登录/注册）作为收受邮件的验证邮箱
密码自定
**Note**: Use your personal email (not a third-party login/registration) as the verification email for receiving messages.
Password can be set as desired.
1.3 注册登录成功
1.3 Successful registration and login
可见用户中心页面，下面进行介绍基本使用：
You will see the user center page. Below is an introduction to basic usage:
1.3.1 免费用户初始赠送1024MB流量，其他流量需登录签到，签到有时需要验证是否为真人
1.3.1 Free users initially receive 1024MB of data. Additional data can be obtained by logging in and checking in, which sometimes requires verification to confirm you are a real person.
1.3.2 免费用户注意不要找客服，可能存在封号的可能
1.3.2 Free users should avoid contacting customer service, as it may result in account suspension.
1.3.3 下方有各个系统的梯子上网使用教程
1.3.3 Below, you will find tutorials for using the VPN service on various systems.
**本人要讲的是Linux 中使用Clash**
**I will explain how to use Clash on Linux.**
根据供应商说法：Linux版访问中国网站不走代理，访问其他国家和地区的网站走代理
According to the supplier: The Linux version does not use a proxy when accessing Chinese websites, but uses a proxy for websites in other countries and regions.
2、上网前准备：
Preparation Before Going Online:
2.1 按顺序点击：Linux - Clash for linux 教程 进入该文档教程页面
2.1 Click in the following order: Linux - Clash for Linux Tutorial to enter the tutorial page.
**注意**：部分内容无法查看，请登录后再查看，因该教程提供针对每个用户的特定链接，而非共性链接
**Note**: Some content may not be viewable. Please log in to view it, as this tutorial provides specific links for each user rather than a common link.
教程页面链接：
Tutorial page link:
{% embed https://v2free.net/doc/#/linux/clash %}.
页面部分内容截图如下：
A screenshot of part of the page content is shown below:
请按照教程，百分百的按照其内容配置
A screenshot of part of the page content is shown below
2.2 唯有不同之处：
2.2 The only difference:
有内容如下：
There is content as follows:
在这里我们进行简单修改，不按照它的配置：
Here we will make a simple modification, not following its configuration:
进入你的 /root 目录，并编辑文件： .bashrc 文件，这里我使用的是vim工具
Go to your /root directory and edit the .bashrc file. I am using the vim tool for this.
```
cd /root
vim .bashrc
```
按键： 英文 I
Press: English I
编写配置如下：
Write the following configuration:
完成后使配置立即生效：
After completion, make the configuration take effect immediately:
```
source .bashrc
```
使用以下命令验证是否生效：
Use the following command to verify if it is effective:
```
echo $http_proxy
echo $https_proxy
```
这里是将在命令行设置的命令，使用在全局环境中
This is a command set in the command line, used in the global environment.
2.3 完整配置完成以后，请使用命令检测：
2.3 After completing the full configuration, please use the command to check:
```
curl -I www.google.com
```
稍等一会，如显示内容如下：
Wait a moment, if the following content is displayed:
```
:~/.config/mihomo# curl -I www.google.com
HTTP/1.1 200 OK
Transfer-Encoding: chunked
......
```
即为可以访问，下面开始配置Docker的代理
It means you can access the internet. Now let's start configuring the Docker proxy.
3、Docker代理配置
3、Docker Proxy Configuration
进入目录：
Navigate to the directory:
```
cd /etc/systemd/system/
```
创建目录并进入：
Create a directory and enter it:
```
docker.service.d
cd docker.service.d
```
vim 创建文件编写内容：
Use vim to create a file and write the content:
```
vim http-proxy.conf
i
[Service]
Environment="HTTP_PROXY=http://127.0.0.1:7890"
shift + :
wq
vim https-proxy.conf
i
[Service]
Environment="HTTPS_PROXY=http://127.0.0.1:7890"
shift + :
wq
```
使用命令如下：
The commands are as follows:
```
sudo systemctl daemon-reload
sudo systemctl restart docker
```
之后命令：
Afterwards, run the command:
```
sudo systemctl show --property=Environment docker
```
确认输出包含 HTTP-PROXY和HTTPS-PROXY
Ensure the output includes HTTP-PROXY and HTTPS-PROXY.
成功后使用命令：
After successful configuration, use the command:
```
docker run busybox wget -O- http://www.google.com
```
完整正确结果如下：
The complete correct result should look like this:
注意：wget 提示can`t是正常情况无需在意
Note: If wget shows a "can't" message, it is normal and can be ignored.
至此，Docker无需国内镜像源即可访问docker 官网
At this point, Docker can access the Docker official website without using domestic mirror sources.
| aionerljjj |
1,885,507 | Fastest Way To Learn a Programming Language | Curiosity The greats love to learn. They love to grow. They never lose their holy... | 0 | 2024-06-13T02:10:00 | https://dev.to/thekarlesi/fastest-way-to-learn-a-programming-language-2kc3 | webdev, beginners, programming, html | ## Curiosity
The greats love to learn. They love to grow. They never lose their holy curiosity.
Look at Michael Jordan for example. He wasn't the best basketball player in his family. He says that his big brother was more skilled than him.
But he was curious.
Education is the game changer. When you invest in your learning, you can see around corners, you collapse the timeline, you figure out how the pros do it. So guess what? You can do it.
Before we continue, if you are struggling with web development, [DM me now](https://x.com/thekarlesi) and I'll get back to you.
## Mentors
There are a lot of advices online from people. Great programmers will tell you to start programming by writing a simple game.
They will say things like "You want to program, just start by writing a simple game like Tetris or Tik-tak-Toe."
If you have ever tried to write Tetris, it is not simple.
Another person will tell you, "Start with C++. That is what they use in the industry. Especially in the gaming community, that is what they use to write gaming engines."
I have no problem with C++ but to begin with it, is madness.
You have to look for the right mentors according to where you are at in your coding journey.
## Persistence
I will take persistence over talent all day.
Back then in my IT classes, there were those who were just good with coding. They just seemed to get it. Over the years though, the tide shifted. Those who persisted got better at it and ultimately landed great jobs.
I'll take persistence over talent all day. Imagine you are building a video gamer character. You are told to choose between two characters. One with great talents and the other one just won't quit. Who would you choose?
I would pick the character that never quits every time.
Because talent does not save you from getting punched in the face.
Talent will help and amplify you, but it will allow you to quit without persistence. I have seen this many times as a basketball player too. The most talented team getting beaten by the most persistent. The guys that keep playing no matter the odds.
Persistence is the thing that will get you through all the storms. It is the thing that will bring you back again and again.
Only then will you start to see the patterns in coding. Then, you can start to dodge those punches. Because you were already hit by them. Those coding errors, you learn to Jiu-Jitsu them.
But you can't dodge those punches moving forward if you never get off the ground.
A talented man can take a hit. Persistence, you can't stop. You can acquire the skill of persistence. That is ultimately the main accomplishment. Because talent is not competency.
Experience and knowing what you are doing make you competent. And that is what will make you win.
## The basics
Coding has only about eight main concepts. You hit them and you are done. The concepts are universal across languages. For those who know multiple languages, they know this is true.
Your first language will be hard, the second and the third, you will start to see patterns.
By the fourth or fifth language, you will be given a project and you can even do it in a weekend.
The first thing you need to do though when you are coding is start with the basics. Write out the concepts first, then convert them to code later. If you are lost in coding, it is almost because you shouldn't be coding yet. Write out the concepts first, then convert them to code later.
It is the same concept as architecture when they start the construction of a building. They come up with the designs first, then from the designs they can come up with the building.
Take a pen and paper if you have to. Visualize the project you are about to build. Have a rough idea before you code.
And you will be way ahead of the project.
## Courses
Did I take some pill to make me a JavaScript wizard overnight? It is straightforward.
Let me take you back to when English was being taught all over the world.
It all started with the British wanting to spread English all over the world. To do this, they created 850 words that anyone could learn and understand.
From these 850 words, you could construct sentences from them.
The same goes for coding. There are some concepts that when you learn, you can code almost any project in this world. Any app in this world.
To learn them, you need to take courses that will teach you these concepts. And then, you will be using these concepts throughout your programming life.
That's it.
Happy coding!
Karl
P.S. If you are struggling with web development, [DM me now](https://x.com/thekarlesi) and I'll get back to you. | thekarlesi |
1,886,357 | Simple AI Smart Home Manager | The code for this post is all available here :... | 0 | 2024-06-13T02:09:34 | https://dev.to/aaronblondeau/simple-ai-smart-home-manager-3pck | genkit, ai, javascript | The code for this post is all available here : [https://github.com/aaronblondeau/genkit-smarthome](https://github.com/aaronblondeau/genkit-smarthome)
View the working app at [https://smarthome.aaronblondeau.com/](https://smarthome.aaronblondeau.com/)
Although I am working to de-google my life, I took note of the recent launch of [Firebase Genkit](https://firebase.google.com/docs/genkit/). I have struggled to get tools like [LangChain](https://www.langchain.com/) to perform well when working with structured data. Since the ability to ingest and output JSON is crucial for AI applications I decided to give Genkit a try. Genkit exceeded my expectations and is now a member of my tech toolbox.
Here is the scenario I used to test Genkit. Imagine you have both a smart-thermostat and a smart-light in your office and you'd like to be able to control them with natural language commands. For example, "Set the lights to green please." or "Set the temperature to eighty please."
For this to work the language model needs a few things:
1) Prompts that specify the desired outcome.
2) A list of the high level actions that can be taken.
3) Tools that help extract formatted data from the user's request (for example, turn "eighty" into 80 so it can be used by the thermostat device).
And I as a developer working on the app have these needs:
1) Ability to test and quickly iterate on each prompt.
2) Detailed output of the chain of prompts and responses that result in fulfillment of a user's request.
3) Ability to use multiple models (even those running locally like ollama).
4) **Reliable structured data output from the llm.**
Genkit does an excellent job of filling these needs. For the developer it provides a UI that helps you to run prompts as well as analyze the inputs/outputs of each step in a multi-prompt workflow. Here is a screenshot of my Genkit UI instance showing all my flows.
There also appears to be support for non-google models : [https://github.com/TheFireCo/genkit-plugins/tree/main](https://github.com/TheFireCo/genkit-plugins/tree/main)
For the language models, Genkit provides the concept of [Flows](https://firebase.google.com/docs/genkit/flows). A flow basically combines a prompt with a set of "tools" or actions that the llm can take. Like other frameworks in this space [ZOD](https://zod.dev/) is used to provide schema information for both the input and output of flows and actions.
For example here is the code for my **flow** that sets the color of lights in a room. It has a prompt that helps set the context of what needs to be done. It also has a set of tools it can use : extractColor, convertColorToHex, setLEDColor
```JavaScript
// Primary level flow for setting the room's lighting.
export const setLightsFlow = defineFlow(
{
name: 'setLightsFlow',
inputSchema: z.object({
command: z.string().describe('The user\'s request for a lighting color change.')
}),
outputSchema: z.string(),
},
async (input) => {
const llmResponse = await generate({
prompt: `Please respond to this command to set the color of lights in the room : ${input.command}`,
model: geminiPro,
tools: [extractColor, convertColorToHex, setLEDColor],
config: standardConfig,
});
return llmResponse.text();
}
);
```
And here is code for an **action** that the model can use to convert color names to hex codes. The really neat thing here is that you can embed a flow within an action.
```JavaScript
// Provides the convertColorToHexFlow as a tool
export const convertColorToHex = action(
{
name: 'convertColorToHex',
description: 'Converts a color string to hex. For example, an input of "blue" outputs "0000FF"',
inputSchema: z.object({ colorString: z.string() }),
outputSchema: z.object({ hexColorCode: z.string().length(6) }),
},
async (input) => {
const response = await runFlow(convertColorToHexFlow, {
color: input.colorString
});
return response
}
);
```
A simpler **action** that takes concrete action on behalf of the user:
```JavaScript
// Low level tool that sets the color of the room's lights
export const setLEDColor = action(
{
name: 'setLEDColor',
description: 'Sets the color of the room\'s lighting by sending commands to the fixture\'s bluetooth API.',
inputSchema: z.object({ hexColorCode: z.string().length(6) }),
outputSchema: z.boolean().describe('True if the color is successfully set.'),
},
async (input) => {
homeActor.send({ type: 'SETCOLOR', value: input.hexColorCode })
return true
}
);
```
homeActor is an [XState](https://stately.ai/docs/xstate) finite state machine. I really like the idea of providing AI models with a state machine that they can manipulate to get to the user's desired outcome. My state machine doesn't do much in this example but I feel like genkit+xstate is a really powerful combo that I am going to explore further.
I won't go into all the other implementation details here, but here are the 3 most important things I learned in getting the project to work:
### 1) Provide a tiered structure of flows and actions
Genkit automatically runs multiple tools in the right order when they are needed to execute a command. However I got quite a few errors when I attempted to have the same flow responsible for multiple jobs. I wound implementing a pattern where the first flow simply determines what type of command the user gave (lights vs thermostat). That high level flow can defer to a tool for each type of command. These tools in turn execute a sub-flow that is job specific. Here is what it looks like:
### 2) Avoid system prompts
The Genkit docs detail how to use system prompts here : https://firebase.google.com/docs/genkit/models
As I am accustomed to using system prompts to give context to the llm I tried them first. However, gemini would return a response of "Understood" from each system prompt which threw off the chain of execution. So I stopped using system prompts and put all my context into each flow's main prompt. Other models are likely to behave differently.
### 3) Avoid simple string schemas for inputs and outputs
Most of my actions and flows simply return a single piece of data like "blue" so I originally setup my flows like this:
```JavaScript
{
name: 'convertColorToHexFlow',
inputSchema: z.string(),
outputSchema: z.string().length(6),
}
```
This flat schema resulted in flows providing a value of {} as input to tools. That issue went away when I made the schemas more descriptive like this:
```JavaScript
{
name: 'convertColorToHexFlow',
inputSchema: z.object({
color: z.string()
}),
outputSchema: z.object({
hexColorCode: z.string().length(6)
}),
}
```
### Summary
Give Genkit a try. It is a minimal framework that will help you manage all the chaos that comes from being proompter.
Thanks for reading!
| aaronblondeau |
1,886,356 | Essential Node.js backend examples for developers in 2024 | Boost your Node.js skills with these backend code snippets for 2024. Copy and paste them into your own projects to save time when building backends. | 0 | 2024-06-13T02:00:17 | https://snyk.io/blog/essential-node-js-backend-examples-2024/ | applicationsecurity, codesecurity, javascript, node | Node.js backend development continues to stand out in 2024 as a powerful and flexible runtime for building scalable and efficient applications, even more so with the rise of other runtimes such as Bun.
In this article, I wanted to provide a lightweight introduction to essential Node.js backend examples that demonstrate the effective use of advanced JavaScript and Node.js features. From harnessing the WHATWG Streams Standard and Web Streams API for efficient data handling to employing the built-in Node.js crypto module for security, working with Buffers for binary data manipulation, leveraging Symbols for encapsulation and namespacing, and utilizing template literals and tagged templates for generating dynamic HTML and SQL queries — each section provides practical, real-world code snippets and insights.
These examples not only showcase the versatility and strength of Node.js in solving backend challenges but also serve as a valuable reference for developers looking to elevate their backend solutions in 2024.
Chapters in this article:
1. The WHATWG Streams Standard, Web Streams API, and async iterables
2. Working with the Crypto module to validate webhook signatures
3. Working with buffers and raw binary data in Node.js
4. Using JavaScript Symbol for encapsulation
5. Template literals and tagged templates to generate HTML and SQL queries
You can always catch up with the full source-code Node.js backend examples in [this GitHub repo](https://github.com/snyk-snippets/modern-nodejs-runtime-features-2024).
1. The WHATWG Streams Standard, Web Streams API, and Async Iterables
--------------------------------------------------------------------
In 2024, the prevalence of working with streams has significantly increased, especially when dealing with large language models for General Artificial Intelligence (GenAI). The OpenAI SDK for chat completion serves as a prime example of this trend. A typical example of streaming data from the OpenAI SDK API would look like this:
```
const completion = await openai.chat.completions.create(config);
for await (const chunk of completion) {
console.log(chunk);
}
```
Here, we use the concept of async iterables, which has simplified asynchronous workflows in Node.js to match the promise-based programming style. The `for await…` statement creates a loop iterating over async iterable objects as well as sync iterables, including built-in String, Array, Array-like objects (e.g., arguments or NodeList), TypedArray, Map, Set, and user-defined async/sync iterables.
### Introducing WHATWG Standard Web Streams in Node.js
Web Streams, a part of the WHATWG Streams standard, have been integrated into Node.js, and they provide a robust way of handling streaming data. This standard allows developers to efficiently read, write, and transform streaming data using JavaScript.
Let's look at a complete example of how to use Web Streams in Node.js.
In the following example, we create a function `createReadableStreamFromFile()` that uses the `ReadableStream` class from the Web Streams API to create a stream of data from a file. A second function, `consumeStreamWithAsyncIterator()`, then consumes this stream using an Async Iterator.
```
import { ReadableStream } from "node:stream/web";
import fs from "fs";
function createReadableStreamFromFile(filePath) {
const stream = new ReadableStream({
start(controller) {
const reader = fs.createReadStream(filePath);
reader.on("data", (chunk) => {
controller.enqueue(chunk);
if (reader.readableFlowing === false) {
reader.resume();
}
});
reader.on("end", () => {
controller.close();
});
reader.on("error", (err) => {
controller.error(err);
});
},
});
return stream;
}
async function consumeStreamWithAsyncIterator(stream) {
try {
for await (const chunk of stream) {
process.stdout.write(chunk);
}
} catch (err) {
console.error("Error occurred while reading the stream:", err);
}
}
const filePath = process.argv[2];
const stream = createReadableStreamFromFile(filePath);
consumeStreamWithAsyncIterator(stream);
```
In this code, we're using the Web Streams API to read data from a file in a streaming manner. The function `createReadableStreamFromFile()` returns a `ReadableStream` object from a given file path. This stream is then consumed by `consumeStreamWithAsyncIterator()`, which reads the stream chunk by chunk and writes each chunk to the standard output. If an error occurs during the reading process, it's caught and logged to the console.
By the way, did you notice the security vulnerability in the code above?
If you had the [Snyk VS Code extension](https://marketplace.visualstudio.com/items?itemName=snyk-security.snyk-vulnerability-scanner) installed, then you’d get a wiggly linter error showing you that there’s a path traversal vulnerability in the code example.
The Snyk VS Code extension would show you how insecure data can flow into this Node.js backend code example, what this security vulnerability is about, and how to fix it with AI-curated suggestions from live open source projects.
2. Working with the Crypto module to validate webhook signatures
----------------------------------------------------------------
Webhooks have become an integral part of modern backend development, providing a way for different services to communicate with each other in an efficient and real-time manner. However, with the increased use of webhooks comes the need for stronger security measures, one of which is the validation of webhook signatures.
In the realm of webhooks, a signature is a hash that is sent along with the webhook payload, which is calculated using a secret key known only to the sender and the recipient. The recipient can then calculate the hash on their end and compare it with the signature to verify the authenticity of the webhook.
The Node.js Crypto module provides a host of cryptographic functionality, including a set of wrappers for OpenSSL's hash, HMAC, cipher, decipher, sign, and verify functions. HMAC (Hash-based Message Authentication Code) is particularly useful for validating webhook signatures.
Let's break down the provided code snippet to understand how it works:
```
const crypto = require("node:crypto");
const secret = process.env.WEBHOOK_SECERT;
const hmac = crypto.createHmac("sha256", secret);
const digest = Buffer.from(
hmac.update(request.rawBody).digest("hex"),
"utf8"
);
const signature = Buffer.from(request.headers["x-signature"] || "", "utf8");
if (!crypto.timingSafeEqual(digest, signature)) {
throw new Error("Invalid signature.");
}
```
In this snippet, the `crypto.createHmac` method is used to create an HMAC object. This method takes two parameters — the algorithm to be used (in this case, `sha256`) and the secret key.
The HMAC object is then updated with the raw body of the webhook request using the `hmac.update` method. This method can be called multiple times with new data as it is streamed.
The `digest` method is then used to generate the hash. This method can only be called once on the HMAC object, and it returns the calculated hash. The `hex` parameter instructs the method to return the hash in hexadecimal format.
Now, we introduce the concept of secure string comparison. The calculated hash (digest) and the received signature from the webhook request header are then compared using the `crypto.timingSafeEqual` method. This method performs a timing-attack safe equality comparison between two buffers, making it ideal for comparing cryptographic outputs.
Timing attacks are a type of side-channel attack where an attacker tries to compromise a system by analyzing the time taken to execute cryptographic algorithms. By using a timing-safe method like `crypto.timingSafeEqual`, we protect against these types of attacks. If the digest and signature do not match, an error is thrown, indicating that the webhook request may not be authentic.
3. Working with buffers and raw binary data in Node.js
------------------------------------------------------
The Buffer API in Node.js is a powerful tool that allows developers to work directly with binary data. Whether you need to read a file, analyze an image, or process raw data, the Buffer API provides methods to handle such tasks efficiently.
Let's explore some of the common Buffer API methods in Node.js, such as `.from`, `.alloc`, and `.write`, which allow for the creation and manipulation of buffer objects. The `.from` method creates a new buffer using the data passed in as an argument, `.alloc` creates a new buffer of a specified size, and `.write` allows you to write data to a buffer. Another one is the `.concat` method, which is used to concatenate a list of Buffer instances.
```
let buffer1 = Buffer.from('Hello, ');
let buffer2 = Buffer.from('World!');
let buffer3 = Buffer.concat([buffer1, buffer2]);
console.log(buffer3.toString());
// prints: 'Hello, World!'
```
### Analyzing an image with OpenAI API using Node.js Buffer API
In the next Node.js backend example code, we are using the Buffer API to read an image file and analyze it using the OpenAI API. Firstly, we import the necessary modules and create an instance of the OpenAI API client:
```
import { readFile } from "node:fs/promises";
import OpenAI from "openai";
const openai = new OpenAI();
```
Next, we read the image file into a buffer:
```
const imageBuffer = await readFileToBuffer(process.argv[2]);
```
We then validate the image type by checking the file signature against a known PNG image type signature:
```
function isImageTypeValid(imageBuffer) {
const pngSignature = Buffer.from([
0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a,
]);
const fileSignature = imageBuffer.slice(0, 8);
if (pngSignature.equals(fileSignature)) {
return true;
}
}
```
Finally, we generate a descriptive alt text for the image using the OpenAI API:
```
async function generateAltTextForImage(imageBuffer) {
const imageInBase64 = imageBuffer.toString("base64");
const response = await openai.chat.completions.create({
model: "gpt-4-vision-preview",
messages: [
{
role: "user",
content: [
{
type: "text",
text: "What's in this image? generate a simple alt text for an image source in an HTML page",
},
{
type: "image_url",
image_url: {
url: `data:image/png;base64,${imageInBase64}`,
},
},
],
},
],
});
return response.choices[0];
}
```
### Security considerations when using Buffer API
When working with the Buffer API, there are several security considerations to keep in mind. Improper handling of binary data can lead to potential security vulnerabilities such as buffer overflow or underflow errors. Always make sure to validate the input and properly handle the errors.
Also, be mindful of potential security vulnerabilities, such as the `Buffer` constructor, which is now deprecated and should be avoided in favor of safer alternatives like `Buffer.from` or `Buffer.alloc`.
4. Using JavaScript Symbol for encapsulation
--------------------------------------------
Symbols are a primitive data type introduced in ES6 (ECMAScript 2015) that represent unique and immutable identifiers. They are created with the `Symbol()` function, which optionally accepts a description (a string) that can be used for debugging but does not affect the uniqueness of the symbol. Symbols are primarily used to create unique property keys for objects that do not collide with any other property, including those inherited. This makes them particularly useful for defining private or special properties of objects without risking property name collisions.
Here's a Node.js backend code example of how to use symbols to create a private property in a class as a way to encapsulate data:
```
const _privateProperty = Symbol('privateProperty');
class MyClass {
constructor(value) {
this[_privateProperty] = value;
}
getPrivateProperty() {
return this[_privateProperty];
}
}
const instance = new MyClass('secret');
console.log(instance.getPrivateProperty());
// Will output 'secret'
// The _privateProperty cannot be directly accessed from outside the class
```
In addition, Symbols are not accessible through object property enumeration (like `for...in` loops or `Object.keys()`), so in a sense, they can be used to simulate private properties and methods for objects, but it's important to note that they are not truly private and can still be accessed using reflection methods like `Object.getOwnPropertySymbols()`.
JavaScript defines a set of well-known symbols that represent internal language behaviors that can be customized by developers. For example, implementing an iterator for a custom object using `Symbol.iterator`:
```
const iterable = {
[Symbol.iterator]: function* () {
yield 1;
yield 2;
}
};
for (const value of iterable) {
// Logs 1 and 2
console.log(value);
}
```
### Fastify’s use of JavaScript's Symbol
Let's look at a more real-world example with the Fastify web application framework and how the project uses Symbols. Specifically, we're going to look at an example from Fastify's plugin architecture. One of the key aspects of Fastify's design is its encapsulation feature, which allows developers to create isolated application contexts using plugins. This is crucial for building large-scale applications where namespace collisions can become a problem.
Fastify uses Symbols to uniquely identify internal properties and methods, ensuring that these do not interfere with user-defined properties or those from other plugins. Here is a simplified example based on the actual use of Symbols in Fastify's source code for encapsulating the plugin's metadata:
```
const pluginMeta = Symbol('fastify.pluginMeta');
function registerPlugin(instance, plugin, options) {
if (!plugin[pluginMeta]) {
plugin[pluginMeta] = { options, name: plugin.name };
}
instance.register(plugin, options);
}
function myPlugin(instance, opts, done) {
done();
}
registerPlugin(fastifyInstance, myPlugin, { prefix: '/api' });
```
In the above, `pluginMeta` is a Symbol used by Fastify to attach metadata to plugin functions. This metadata includes the plugin's options, name, and potentially other necessary information for the framework's internal use. The `registerPlugin` function simplifies the process of attaching metadata to a plugin before registering it with a Fastify instance. This metadata is then accessible within the Fastify framework but remains isolated from the plugin's public interface and the application's global scope.
The benefits of using JavaScript's Symbol for internal metadata like this has several advantages in a framework like Fastify:
* Encapsulation: It prevents internal details from leaking into the user space, keeping the public API clean and intuitive.
* Safety: It reduces the risk of accidental interference between plugins or between a plugin and the core framework, as Symbols are not accessible through normal object property enumeration.
* Clarity: It clearly distinguishes between the framework's internal mechanisms and the APIs exposed to developers, making the Fastify codebase easier to maintain and extend.
5. Template literals and tagged templates to generate HTML and SQL queries
--------------------------------------------------------------------------
Introduced in ES6, template literals offer a more readable and concise syntax for creating strings in JavaScript, and you might have been using template literals already in JavaScript to write strings and integrate dynamic expressions — such as `hello ${name}`. No more string concatenation.
We're now seeing a growing trend of using template literals in the form of tagged templates to generate HTML and SQL queries in Node.js backends. Here are two real-world examples in Node.js backend and SSR code:
### Tagged templates for generating SQL queries with Vercel's PostgreSQL library
Dealing with SQL queries in Node.js can often lead to verbose and error-prone code, especially when dynamically inserting values into queries. Vercel's PostgreSQL package (`@vercel/postgres`) introduces a safer and more concise way to format SQL queries using template literals:
```
import { sql } from '@vercel/postgres';
const jediName = 'Luke Skywalker';
const { rows } = await sql`SELECT * FROM jedis WHERE name = ${jediName};`;
```
The SQL-tagged template literal function safely interpolates the `jediName` variable into the SQL query, effectively preventing SQL injection attacks.
### Tagged templates for generating HTML on Fastify servers
Similar to the SQL query, the `fastify-html` is a Fastify plugin that allows developers to use tagged templates to generate HTML content directly in route handlers. This can be particularly useful for server-side rendering (SSR) or generating dynamic HTML content (did someone say htmx?):
```
import fastify from 'fastify'
import fastifyHtml from 'fastify-html'
const app = fastify()
await app.register(fastifyHtml)
app.get('/', async (req, reply) => {
const name = req.query.name || 'World';
return reply.html`Hello ${name}
=============
`;
});
```
**Closing up**
--------------
If you liked this article, you might also want to check out [best practices for creating a modern npm package with security in mind](https://snyk.io/blog/best-practices-create-modern-npm-package/) and [10 best practices to containerize Node.js web applications with Docker](https://snyk.io/blog/10-best-practices-to-containerize-nodejs-web-applications-with-docker/).
And if you're into security stories, you’ll want to make sure you're well-equipped to [combat supply chain attacks on npm](https://snyk.io/blog/npm-security-preventing-supply-chain-attacks/) with developer security practices that I mentioned in the article.
Lastly, don't forget to check out [Snyk with a free account](https://snyk.io/signup) to start securing your Node.js code, dependencies, and Docker container images.
| snyk_sec |
1,886,229 | Awesome Open-Source 😎 | Welcome! 👋 Here you can find a curated list of all the best free and open-source software... | 27,705 | 2024-06-13T02:00:03 | https://dev.to/superp0sit1on/awesome-open-source-38h6 | opensource, community, productivity | ## Welcome! 👋
Here you can find a curated list of all the best free and open-source software for every need!
## Summary 📋
- [Audio 🎧](#audio)
- [Development 💻](#development)
- [Game Development 🎮](#game-development)
- [Graphics 🖼️](#graphics)
- [Operational Systems 🖥️](#operational-systems)
- [Productivity 📎](#productivity)
- [Social networks 💬](#social-networks)
- [Video 🎥](#video)
- [Web Browsing 🌐](#web-browsing)
---
## Audio 🎧
- [Ardour](https://ardour.org) - Comprehensive digital audio workstation for professional use.
- [Audacity](https://www.audacityteam.org) - The most famous digital audio editor.
- [Cider](https://cider.sh/) - Multi-platform and beautifully crafted Apple Music interface.
- [Rhythmbox](https://www.rhythmbox.org) - The traditional audio player from GNOME and the community.
## Development 💻
- [Apache NetBeans](https://netbeans.apache.org) - Classic IDE for Java development.
- [Git](https://www.git-scm.com) - The most famous and used version-controlling system.
- [GitHub Desktop](https://desktop.github.com) - Git graphical interface for managing repositories.
- [VSCodium](https://vscodium.com) - VSCode without any Microsoft telemetry.
- [Zed](https://zed.dev) - New IDE from the creators of Atom, focused on speed, collaboration, and optimal developer experience.
## Game Development 🎮
- [GDevelop](https://gdevelop.io) - No-code newbie-friendly game engine.
- [Godot](https://godotengine.org) - The most comprehensive and loved game engine.
## Graphics 🖼️
- [Blender](https://www.blender.org) - Most powerful 3D modelling tool.
- [Blockbench](https://www.blockbench.net) - 3D low-poly modelling tool.
- [Darktable](https://www.darktable.org) - Lightroom-like photo editing tool.
- [GIMP](https://www.gimp.org) - Most powerful image manipulation tool.
- [Inkscape](https://inkscape.org) - Traditional vector graphics editor.
- [Krita](https://krita.org) - Powerful illustration tool.
- [LibreCAD](https://www.librecad.org) - Traditional and powerful CAD tool.
- [LibreSprite](https://libresprite.github.io) - Pixel-art editor, forked from Aseprite.
- [penpot](https://penpot.app) - Self-hosted collaborative prototyping tool.
- [PhotoGIMP](https://github.com/Diolinux/PhotoGIMP) - Photoshop-like patched GIMP.
## Operational Systems 🖥️
- [Debian](https://www.debian.org) - The most famous and used Linux distro of all time, focused on security and stability.
- [Endless OS](https://www.endlessos.org) - The famous encyclopedia Linux distro.
- [Fedora](https://fedoraproject.org) - Enterprise-grade Linux distro from RedHat.
- [Kali Linux](https://www.kali.org) - The one Linux distro for hackers.
- [Manjaro](https://manjaro.org) - User-friendly and Arch-based Linux distro.
- [Mint](https://www.linuxmint.com) - Windows-like and user-friendly Linux distro.
- [Slackware](http://www.slackware.com) - The one Linux distro for hardcore users.
- [Tails](https://tails.net) - Privacy-focused Linux distro.
- [Ubuntu](https://ubuntu.com) - The most famous newbie-friendly Linux distro based on Debian.
- [Zorin OS](https://zorin.com/os) - Windows-like comprehensive Linux distro.
- [elementary OS](https://elementary.io) - macOS-like and friendly user experience.
- [openSUSE](https://www.opensuse.org) - Famous working-station Linux distro.
- [PopOS](https://pop.system76.com) - The comprehensive Linux distro for STEM and creative professionals.
## Productivity 📎
- [BitWarden](https://bitwarden.com) - Best-in-class password manager.
- [HedgeDoc](https://hedgedoc.org) - Self-hosted collaborative markdown note-taking.
- [Jitsi](https://meet.jit.si) - Easy and secure audio & video meetings.
- [Joplin](https://joplinapp.org) - Powerful note-taking application.
- [LibreOffice](https://www.libreoffice.org) - The most famous open-source Microsoft Office alternative.
- [Obsidian](https://obsidian.md) - Powerful note-taking and mind mapping application.
- [Ollama](https://www.ollama.com) - Self-hosted large language models (LLMs).
- [Thunderbird](https://www.thunderbird.net) - Famous email client from Mozilla.
## Social networks 💬
- [Forem](https://github.com/forem/forem) - Self-hosted forum platform from the creators of the DEV Community.
- [Mastodon](https://mastodon.social) - The most famous decentralized micro-blogging social network.
- [Pixelfed](https://pixelfed.org) - Decentralized photo sharing.
- [WordPress](https://wordpress.com) - The most famous blog authoring platform.
- [friendica](https://friendi.ca) - Traditional and decentralized social network.
- [writefreely](https://writefreely.org) - Self-hosted and distraction-free blog authoring tool.
## Video 🎥
- [kdenlive](https://kdenlive.org) - Powerful and comprehensive video editing tool.
- [OBS Studio](https://obsproject.com) - The most used and powerful live streaming tool.
- [OpenShot](https://www.openshot.org) - Powerful video editing tool.
- [Owncast](https://owncast.online) - Self-hosted live streaming platform.
- [PeerTube](https://joinpeertube.org) - Decentralized video-hosting platform.
- [VLC](https://www.videolan.org) - Traditional and comprehensive player.
## Web Browsing 🌐
- [Firefox](https://www.mozilla.org/firefox/new) - Simply one of the most used browsers ever!
- [ungoogled-chromium](https://ungoogled-software.github.io) - Chromium (Chrome) without any Google telemetry and possibly annoying stuff.
---
### Want to contribute? 🤝
This list is updated occasionally (and currently manually 🥲) on the DEV Community and is open to contributions on our [GitHub repository](https://github.com/Superp0sit1on/awesome-open-source)! So feel free to open a pull request and help the open-source community shine!
> 😎 Pro-tip: Don't forget to read our [code of conduct](https://github.com/Superp0sit1on/awesome-open-source/blob/main/CODE_OF_CONDUCT.md) and the [contributing guidelines](https://github.com/Superp0sit1on/awesome-open-source/blob/main/CONTRIBUTING.md). | superp0sit1on |
1,886,352 | Ada Maurice : La Plateforme Éclatante de l'Art Mauricien | Ada Maurice se distingue comme une vitrine virtuelle éblouissante pour l'art contemporain de l'île... | 0 | 2024-06-13T01:53:08 | https://dev.to/joseph_wilson_/ada-maurice-la-plateforme-eclatante-de-lart-mauricien-4o9m | career, webdev | Ada Maurice se distingue comme une vitrine virtuelle éblouissante pour l'art contemporain de l'île Maurice. Cette plateforme en ligne dédiée à la promotion des talents locaux offre aux passionnés d'art du monde entier une opportunité unique de découvrir et d'acquérir des œuvres inspirantes qui captivent par leur originalité et leur créativité.
Une Collection Variée et Inspirante
La galerie en ligne d'Ada Maurice présente une collection diversifiée d'œuvres d'art, allant de la peinture et la sculpture à la photographie et l'art numérique. Chaque pièce est minutieusement sélectionnée pour sa qualité esthétique et sa capacité à refléter l'âme vibrante de Maurice. Les artistes présentés sur Ada Maurice capturent non seulement la beauté naturelle de l'île, mais ils explorent également des thématiques contemporaines et universelles à travers leur art.
Engagement envers la Communauté Artistique
En plus de servir de plateforme de vente en ligne pour les œuvres d'art, Ada Maurice s'engage activement à soutenir la communauté artistique mauricienne. Ils organisent régulièrement des événements culturels tels que des expositions, des vernissages et des discussions artistiques qui enrichissent le dialogue artistique local et international. Ces initiatives non seulement célèbrent l'art, mais elles renforcent également les liens entre les artistes et le public.
Accessibilité et Visibilité Mondiale
Ada Maurice offre aux artistes mauriciens une visibilité mondiale, permettant à leurs créations d'atteindre des collectionneurs et des amateurs d'art à travers le monde. Grâce à une interface conviviale et une navigation intuitive, les visiteurs du site peuvent explorer facilement les œuvres disponibles, en apprendre davantage sur les artistes et même acquérir des pièces qui résonnent avec eux.
Pourquoi Ada Maurice est Essentiel
Que vous soyez un collectionneur passionné, un amateur d'art ou simplement curieux de découvrir la scène artistique mauricienne, Ada Maurice vous invite à plonger dans un univers où l'expression créative et la beauté artistique se rencontrent harmonieusement. Chaque visite sur leur site web est une invitation à explorer, à apprendre et à apprécier l'art mauricien contemporain sous toutes ses formes.
Pour en savoir plus sur Ada Maurice et pour découvrir leur galerie d'art en ligne, visitez leur site web à l'adresse suivante : [](https://ada-maurice.com/)https://ada-maurice.com/.
| joseph_wilson_ |
1,886,350 | Crafting a Long-term Sustainable Business: Your 2024 Continuity Checklist | In an ever-evolving economic landscape, the key to maintaining a thriving business is embracing... | 0 | 2024-06-13T01:50:05 | https://dev.to/bocruz0033/crafting-a-long-term-sustainable-business-your-2024-continuity-checklist-1i4f | riskmanagement, sustainability, businesscontinuity | In an ever-evolving economic landscape, the key to maintaining a thriving business is embracing adaptability while focusing on sustainability. The year 2024 presents new challenges and opportunities for business leaders committed to long-term success. Here's your [essential continuity checklist](https://getwpfunnels.com/business-continuity-checklist/) to ensure your business not only survives but thrives in the coming years.
## 1. Review and Reinforce Your Business Mission
Begin by revisiting your business mission and core values. Are they still aligned with your current operations and future goals? Ensure that your mission statement reflects your commitment to sustainability and ethical practices, as these are increasingly important to consumers and stakeholders.
## 2. Adopt Green Technologies and Practices
Integrate sustainable technologies and green practices into your operations. This could range from reducing waste, conserving energy, using sustainable materials, or investing in clean energy sources. Not only do these practices reduce your ecological footprint, but they can also result in cost savings and improve your brand image.
## 3. Strengthen Your Supply Chain
Analyze your supply chain for any vulnerabilities, especially those related to environmental and economic sustainability. Consider diversifying your suppliers or shifting towards more local and sustainable sources. This reduces risks associated with geopolitical issues, transportation costs, and carbon footprints.
## 4. Focus on Financial Health
Ensure your financial strategies are robust. This involves maintaining a healthy cash flow, setting aside adequate reserves, and planning for contingencies. Invest in forecasting tools and technologies that enhance your ability to predict and respond to market changes.
## 5. Invest in Your Team
Your employees are your most valuable asset. Invest in training and development programs that not only enhance their skills but also improve their job satisfaction and alignment with your sustainability goals. Consider flexible work arrangements to help retain talent and reduce carbon emissions related to commuting.
## 6. Enhance Customer Engagement
Deepen your relationship with customers by engaging with them on issues of sustainability. Use your platforms to communicate your efforts and involve customers in your sustainability journey. Feedback mechanisms and customer involvement can provide valuable insights and foster loyalty.
## 7. Regularly Evaluate Risks
Risk management is crucial, particularly in a rapidly changing world. Regularly assess and plan for potential risks, including environmental, technological, and economic challenges. Scenario planning can be particularly useful in preparing for various future conditions.
## 8. Leverage Technology for Efficiency
Utilize technology to streamline your operations and enhance efficiency. Automation, AI, and data analytics can provide critical insights into your operations, optimize processes, and reduce waste. This technological adoption should also consider the sustainability of the technologies themselves.
## 9. Maintain Compliance and Stay Informed
Regulatory environments, especially around sustainability and corporate governance, are constantly evolving. Stay informed about new regulations and ensure your business remains compliant to avoid fines and reputational damage.
## 10. Develop a Sustainable Marketing Strategy
Market your sustainability efforts effectively. A transparent and honest approach in advertising your green policies can help you stand out in a crowded market. Ensure that your marketing strategies are sustainable themselves, avoiding greenwashing and focusing on genuine practices.
## Conclusion
The path to crafting a sustainable business requires a deep commitment to strategic planning and the willingness to adapt to new challenges. By following this continuity checklist, you can position your business for success in 2024 and beyond, ensuring it remains resilient, relevant, and responsible. | bocruz0033 |
1,886,349 | Importância da criação de ambientes virtuais. | Estudando sobre o uso de ambientes virtuais em Python, percebi que o principal motivo é evitar... | 0 | 2024-06-13T01:47:38 | https://dev.to/wallace_03/importancia-da-criacao-de-ambientes-virtuais-1ej8 | python, dicas, webdev | Estudando sobre o uso de ambientes virtuais em Python, percebi que o principal motivo é evitar conflitos entre as bibliotecas instaladas via Python. Por exemplo, se você tem um cliente com um site criado usando Django 2.2.2 e ele não quer atualizar para uma versão mais recente, mas ainda precisa de manutenção, você terá que usar a versão do Django que está instalada na aplicação dele. Enquanto isso, outro cliente pode usar Django 4.2.1. Assim, cada versão do Django deve ser instalada separadamente em ambientes virtuais para evitar conflitos.
Além disso, ambientes virtuais oferecem outros benefícios importantes, como:
Isolamento de Dependências: Garantem que as dependências de um projeto não interfiram nas dependências de outro, permitindo que cada projeto tenha suas próprias versões específicas de bibliotecas.
Facilidade de Gestão: Simplificam a gestão das bibliotecas, permitindo atualizações, adições ou remoções de pacotes sem afetar o sistema global ou outros projetos.
Reprodutibilidade: Facilitam a criação de ambientes reprodutíveis. Com um arquivo requirements.txt, é possível recriar o ambiente exato em outra máquina.
Segurança: Ajudam a proteger o sistema principal de possíveis problemas causados por bibliotecas experimentais ou instáveis.
Logo, o uso de ambientes virtuais é essencial para manter a organização e a eficiência no desenvolvimento de projetos em Python. | wallace_03 |
1,886,348 | How to efficiently use drf_social_oauth2 and django_rest_framework_simplejwt | Hey guys!! So I was working on a rest api application with django and django rest framework but then... | 0 | 2024-06-13T01:43:40 | https://dev.to/codewitgabi/how-to-efficiently-use-drfsocialoauth2-and-djangorestframeworksimplejwt-23i5 | backend, django, oauth, tutorial | Hey guys!!
So I was working on a rest api application with django and django rest framework but then I happened to run into a lot of issues using drf_social_oauth2 and django_rest_framework_simplejwt. The issue was that the former strictly uses `Bearer` authentication header while the latter uses `any` authorization header of your choice so what I did initially was to use `JWT` for simplejwt. This worked fine even though on the client side, my team and I had to write some logic to know if the user initially logged in via oauth or regular auth. This was okay but I was not too comfortable with it. I later thought of a solution to fix the issue and today, I will be showing you what I did to fix this boring issue.
```python
# settings.py
# before
REST_FRAMEWORK = {
"DEFAULT_AUTHENTICATION_CLASSES": (
"rest_framework_simplejwt.authentication.JWTAuthentication",
"oauth2_provider.contrib.rest_framework.OAuth2Authentication",
"drf_social_oauth2.authentication.SocialAuthentication",
),
}
```
```python
# settings
# after
REST_FRAMEWORK = {
"DEFAULT_AUTHENTICATION_CLASSES": (
"rest_framework_simplejwt.authentication.JWTAuthentication",
),
}
```
So from the two code in our settings.py, you can see we had to remove the oauth2_provider and simplejwt authentication from the authentication classes and that's because we will no longer be using it to authenticate. We will default back to using simplejwt and that brings us to the next part.
```python
# views.py
# builtin imports
from json import loads as json_loads
from datetime import datetime
from oauth2_provider.settings import oauth2_settings
from oauth2_provider.views.mixins import OAuthLibMixin
from oauthlib.oauth2.rfc6749.errors import (
InvalidClientError,
UnsupportedGrantTypeError,
AccessDeniedError,
MissingClientIdError,
InvalidRequestError,
)
from django.views.decorators.csrf import csrf_exempt
from django.utils.decorators import method_decorator
from django.contrib.auth import get_user_model
# third party imports
from rest_framework.response import Response
from rest_framework.views import APIView
from rest_framework.permissions import AllowAny
from rest_framework_simplejwt.tokens import RefreshToken, AccessToken
from rest_framework.status import HTTP_400_BAD_REQUEST
from rest_framework.request import Request
from drf_social_oauth2.serializers import ConvertTokenSerializer
from drf_social_oauth2.oauth2_backends import KeepRequestCore
from drf_social_oauth2.oauth2_endpoints import SocialTokenServer
# user object
User = get_user_model()
class CsrfExemptMixin:
"""
Exempts the view from CSRF requirements.
NOTE:
This should be the left-most mixin of a view.
"""
@method_decorator(csrf_exempt)
def dispatch(self, *args, **kwargs):
return super(CsrfExemptMixin, self).dispatch(*args, **kwargs)
class ConvertTokenView(CsrfExemptMixin, OAuthLibMixin, APIView):
"""
Implements an endpoint to convert a provider token to an access token
The endpoint is used in the following flows:
* Authorization code
* Client credentials
"""
server_class = SocialTokenServer
validator_class = oauth2_settings.OAUTH2_VALIDATOR_CLASS
oauthlib_backend_class = KeepRequestCore
permission_classes = (AllowAny,)
def post(self, request: Request, *args, **kwargs):
serializer = ConvertTokenSerializer(data=request.data)
serializer.is_valid(raise_exception=True)
# Use the rest framework `.data` to fake the post body of the django request.
request._request.POST = request._request.POST.copy()
for key, value in serializer.validated_data.items():
request._request.POST[key] = value
try:
url, headers, body, status = self.create_token_response(request._request)
except InvalidClientError:
return Response(
data={"invalid_client": "Missing client type."},
status=HTTP_400_BAD_REQUEST,
)
except MissingClientIdError as ex:
return Response(
data={"invalid_request": ex.description},
status=HTTP_400_BAD_REQUEST,
)
except InvalidRequestError as ex:
return Response(
data={"invalid_request": ex.description},
status=HTTP_400_BAD_REQUEST,
)
except UnsupportedGrantTypeError:
return Response(
data={"unsupported_grant_type": "Missing grant type."},
status=HTTP_400_BAD_REQUEST,
)
except AccessDeniedError:
return Response(
{"access_denied": f"The token you provided is invalid or expired."},
status=HTTP_400_BAD_REQUEST,
)
body = json_loads(body)
if "error" in body:
return Response(data=body, status=status)
token = body.get("access_token")
user = User.objects.filter(oauth2_provider_accesstoken__token=token)[0]
refresh = RefreshToken.for_user(user)
access_token = str(refresh.access_token)
decoded_token = AccessToken(access_token)
expiration_time = datetime.fromtimestamp(decoded_token["exp"])
return Response(
{
"id": user.id,
"first_name": user.first_name,
"last_name": user.last_name,
"middle_name": user.middle_name,
"fullname": f"{user.first_name} {user.last_name}",
"email": user.email,
"phone": user.phone.as_e164,
"profile_picture": (user.profile_pic.url if user.profile_pic else None),
"refresh": str(refresh),
"access": access_token,
"expiry": expiration_time,
},
status=status,
)
```
It's a lot but for now, just `ctrl + c` and `ctrl + v`. The code is from the official [drf_social_oauth](https://github.com/wagnerdelima/drf-social-oauth2) codebase, I'm just overriding it.
`token = body.get("access_token")` gets the `access_token` from the body after the social auth access token has been converted.
`user = User.objects.filter(oauth2_provider_accesstoken__token=token)[0]` gets the user that is associated with the token.
```python
refresh = RefreshToken.for_user(user)
access_token = str(refresh.access_token)
decoded_token = AccessToken(access_token)
expiration_time = datetime.fromtimestamp(decoded_token["exp"])
```
Here is where we change things.
First, we create a `simplejwt` refresh token for the user. Then we get the `access token` and `expiration_time` of the token. This is the token that will be used by the user to authenticate views.
With this, everything is done. You can now authenticate using `Bearer` in the authentication header. | codewitgabi |
1,886,339 | Gemika's Awesome Git Adventures: A Fun Guide to Coding Magic! 🧙♂️✨ | Greetings, young wizards and witches! Allow me to whisk you away into a tale of enchantment and... | 0 | 2024-06-13T01:43:16 | https://dev.to/gerryleonugroho/gemikas-awesome-git-adventures-a-fun-guide-to-coding-magic--4p49 | git, github, webdev, beginners | Greetings, young wizards and witches! Allow me to whisk you away into a tale of enchantment and wonder. I am Uncle Gerry, the proud father of the extraordinary young wizard, Gemika Haziq Nugroho. 🧙♂️✨ In the muggle world, I work my magic as a data-driven marketer and software engineer. This means I use numbers and mystical computer codes to create marvelous things on the internet. But do you know what keeps my mind as clear as a crystal ball? Crafting software! It's like weaving a spellbinding story with my computer! 🌟💻
And of course, I cherish my son Gemika deeply and always wish to share these magical spells with him and with you, his fellow young sorcerers. 🌟❤️ I find great joy in teaching bright young minds like yours about the enchanting world of technology and programming. I strive to make it as simple and delightful as a game of Quidditch! 🧑🏫✨ So, let's embark on this magical journey together, with plenty of smiles, wonder, and excitement! 😄🚀🧙♀️✨
---
## What is Git? 🧙♂️🧩
Before we dive into the magic tricks, let’s talk about what _Git_ is. Git is like a magic notebook where developers (those are people who make cool computer stuff & softwares) can write down their work and share it with friends. Imagine a giant playground where everyone can build and play together, but instead of sand and swings, there are codes and computers.
Git helps keep all the drawings and LEGO projects organized so nobody loses their cool ideas. We use something called a _terminal_ to talk to Git, which is like using a magic wand to give it commands. Ready to learn some magic tricks? Let’s go! 🚀✨
### 1. Git Init: Starting the Magic 🪄
Imagine you have a brand new coloring book, and you want to start a new picture. But first, you need to let everyone know you're beginning a masterpiece. `git init` is like telling everyone, "_Hey, I'm starting a new project!_"
**Real-Life Example:**
Think of it like standing in front of a big blank chalkboard and saying, "_I'm going to draw something amazing here!_" It’s the first step to creating something wonderful.
```bash
git init
```
🎨 **Uncle Gerry's Tip:** It’s like opening a brand new coloring book. Exciting, right? 🖍️
### 2. Git Clone: Copying the Playground 📋
Sometimes, you see an amazing drawing your friend made, and you want a copy so you can color it yourself. `git clone` helps you do just that. It copies all the magic from your friend’s project to your own computer.
**Real-Life Example:**
Imagine your friend has a super cool LEGO castle, and you want to build one just like it. `git clone` gives you all the same pieces so you can start building your own castle!
```bash
git clone https://github.com/friend/project
```
🏰 **Uncle Gerry's Tip:** It’s like copying your friend’s awesome LEGO creation. Now you both have cool castles! 🏰✨
### 3. Git Add: Choosing What to Save ✅
Imagine you've colored a part of your drawing and you want to show it to everyone. `git add` is like picking the parts you want to show off.
**Real-Life Example:**
Think of it like picking out the best parts of your LEGO castle to show your parents. "_Look, I built the drawbridge and the towers!_" When you use `git add`, you're saying, "_This part is ready to be saved and shared!_"
```bash
git add my-drawing.png
```
🎨 **Uncle Gerry's Tip:** It’s like saying, "Look at this cool part I just made!" 😎🖌️
### 4. Git Commit: Saving Your Work 💾
After choosing what you want to show, you need to save it in your special drawing book. `git commit` does that. It saves your chosen parts with a little note about what you did.
**Real-Life Example:**
Imagine you take a photo of your LEGO castle and write a note, "Finished the drawbridge today!" `git commit` is like putting that photo and note in your scrapbook. This way, you’ll always remember what you worked on and can look back at it later.
```bash
git commit -m "Finished coloring the sky"
```
📸 **Uncle Gerry's Tip:** It’s like saving a picture of your LEGO castle in your scrapbook with a note about what you built! 📖✨
### 5. Git Push: Sharing with Friends 🚀
Now that you've saved your drawing, you want to share it with all your friends. `git push` sends your saved work to the playground (GitHub) for everyone to see.
**Real-Life Example:**
It’s like putting your LEGO castle on display at the park so all your friends can see it and admire your hard work. When you use `git push`, you’re saying, "_Hey everyone, look at what I made!_"
```bash
git push
```
🌟 **Uncle Gerry's Tip:** It’s like showing off your awesome LEGO castle to all your friends! 🏞️🧑🤝🧑✨
### 6. Git Pull: Getting Updates 📥
Sometimes, your friends might add new cool things to their drawings, and you want to get those updates. `git pull` brings those changes to your drawing so you always have the latest version.
**Real-Life Example:**
Imagine your friend adds a secret tunnel to their LEGO castle, and you want to add it to yours too. `git pull` helps you get that update and add it to your own castle.
```bash
git pull
```
🔄 **Uncle Gerry's Tip:** It’s like updating your LEGO castle with the new secret tunnel your friend built! 🚇✨
### 7. Git Status: Checking Your Work 📝
If you're ever confused about what's happening with your drawing, `git status` helps you check if everything's in order and if you need to do anything next.
**Real-Life Example:**
It’s like taking a step back and looking at your LEGO castle to see what you’ve built so far and what pieces you might need to add next. When you use `git status`, you’re checking on your project to see what’s done and what’s not.
```bash
git status
```
🔍 **Uncle Gerry's Tip:** It’s like taking a quick look at your LEGO project to see what’s done and what’s next! 🧩👀
### 8. Git Branch: Trying New Things 🌿
Imagine you want to try drawing something different without messing up your main drawing. `git branch` lets you create a new piece of paper where you can experiment.
**Real-Life Example:**
Think of it like starting a new page in your coloring book to try out a different color scheme for your castle. If you like it, you can add it to your main picture later. With `git branch`, you can try new things without messing up your original work.
```bash
git branch new-idea
```
🖌 **Uncle Gerry's Tip:** It’s like trying new colors on a separate piece of paper before adding them to your masterpiece. 🖍️✨
### 9. Git Checkout: Switching Papers 📄
When you want to switch between your main drawing and your new experiment, `git checkout` helps you do that easily.
**Real-Life Example:**
It’s like flipping back and forth between pages in your coloring book to work on different drawings. You can switch back to your main drawing anytime you want and continue working on it.
```bash
git checkout new-idea
```
📖 **Uncle Gerry's Tip:** It’s like turning the pages in your coloring book to work on different pictures. 📚✨
### 10. Git Merge: Combining Drawings 🔀
If you like your new experiment and want to add it to your main drawing, `git merge` combines them into one beautiful piece.
**Real-Life Example:**
Imagine you tried a new color scheme for your castle on a different page, and now you want to add those colors to your main drawing. `git merge` makes that happen, bringing all your ideas together.
```bash
git merge new-idea
```
🌈 **Uncle Gerry's Tip:** It’s like combining your favorite parts from different drawings into one amazing masterpiece! 🎨✨
### 11. Git Log: Storybook of Changes 📚
To remember everything you've done, `git log` shows you a storybook of all the changes you and your friends have made to your drawings.
**Real-Life Example:**
It’s like keeping a diary of your LEGO building adventures, with pictures and notes about every cool thing you added or changed. Every time you make a change, you can look back at your diary and see what you did.
```bash
git log
```
📖 **Uncle Gerry's Tip:** It’s like reading a diary that tells the story of your LEGO castle’s creation! 📓✨
### 12. Git Revert: Fixing Mistakes 🧹
Sometimes, we make mistakes, and that’s okay! `git revert` lets you go back and fix those mistakes, just like erasing a part of your drawing to make it better.
**Real-Life Example:**
Imagine you accidentally knocked over part of your LEGO castle. `git revert` is like having a magic power to rebuild it just the way it was before! It helps you undo mistakes and keep everything looking great.
```bash
git revert bad-change
```
🧩 **Uncle Gerry's Tip:** It’s like having a magic eraser to fix any mistakes in your LEGO castle! 🧽✨
And there you have it, kiddo! These are the magical commands that help developers like Uncle Gerry make awesome things every day. Remember, practice makes perfect, so keep trying these out and one day, you might become a tech wizard too! 🌟🚀✨
---
### Let's Recap with Lots of Fun Emojis! 🎉
1. **Git Init** 🪄: Start your magic coloring book! 🎨🖍️
2. **Git Clone** 📋: Copy your friend's awesome LEGO castle! 🏰✨
3. **Git Add** ✅: Choose the best parts to show off! 😎🖌️
4. **Git Commit** 💾: Save your cool creations with a note! 📸✨
5. **Git Push** 🚀: Share your masterpiece with friends! 🌟🏞️
6. **Git Pull** 📥: Get the latest updates for your project! 🔄✨
7. **Git Status** 📝: Check what’s done and what’s next! 🔍👀
8. **Git Branch** 🌿: Try new things on a separate page! 🖍️✨
9. **Git Checkout** 📄: Switch between different drawings! 📚✨
10. **Git Merge** 🔀: Combine all your cool ideas! 🎨✨
11. **Git Log** 📚: Read the story of your creation! 📓✨
12. **Git Revert** 🧹: Fix mistakes with a magic eraser! 🧽✨
### Embracing the Journey
_JazakAllah Khair_ (جزاك الله خيراً) which means "_May Allah reward you with goodness_" for joining me on this magical journey. May your path be filled with knowledge, creativity, and lots of fun! 🌟📚✨ And _In Sha Allah_ (God willing), you'll continue to explore the wonders of technology and coding. With each command you learn, you're opening a door to new possibilities and adventures. 🌟🚪✨ Always remember little buddy, learning new things and creating awesome projects is like a wonderful adventure.
Just like building a LEGO castle or drawing your favorite superheroes, coding is a fun way to use your imagination and make amazing things. 🌟🚀 Keep practicing, keep learning, and one day, you'll be an inspiring data driven marketer & tech developer! Remember to always seek knowledge, say _Alhamdulillah_, and have fun with every step. 🌟📚✨
_JazakAllah Khair_,
Uncle G 🚪📚✨ | gerryleonugroho |
1,886,346 | Containers - DEV Computer Science Challenge | This is a submission for DEV Computer Science Challenge v24.06.12: One Byte Explainer. ... | 0 | 2024-06-13T01:33:31 | https://dev.to/andresordazrs/containers-dev-computer-science-challenge-1576 | devchallenge, cschallenge, computerscience, beginners | _This is a submission for DEV Computer Science Challenge v24.06.12: One Byte Explainer._
## Containers
<!-- Explain a computer science concept in 256 characters or less. -->
Think of containers as take-out boxes. Each box contains everything an application needs to run and can be used anywhere. Just like take-out boxes keep food consistent and portable, containers ensure apps run reliably across different environments.
<!-- Please share any additional context you think the judges should take into consideration as it relates to your One Byte Explainer. -->
<!-- Team Submissions: Please pick one member to publish the submission and credit teammates by listing their DEV usernames directly in the body of the post. -->
<!-- Don't forget to add a cover image to your post (if you want). -->
<!-- Thanks for participating! --> | andresordazrs |
1,886,347 | Simplifying Serverless Architecture with Terraform and AWS Lambda | I will detail how to automate serverless architecture using Terraform as Infrastructure as Code... | 0 | 2024-06-13T01:32:47 | https://dev.to/etorralbab/simplifying-serverless-architecture-with-terraform-and-aws-lambda-2o7n | serverless, apigateway, terraform, lambda | I will detail how to automate serverless architecture using Terraform as Infrastructure as Code (IaC), focusing on setting up an API Gateway and integrating it with AWS Lambda functions using TypeScript.
## TL;DR:
- **Project Setup**: Organize your project structure and initialize an npm project for managing dependencies.
- **Lambda Functions**: Develop two AWS Lambda functions in TypeScript to process API requests, using essential modules like `aws-lambda` and `base-64`.
- **Building and Deployment**: Utilize `esbuild` to compile and zip your Lambda function code, automating the process with a custom Bash script.
- **Terraform Configuration**: Configure Terraform for both AWS Lambda and API Gateway. This includes setting up IAM roles, CloudWatch logs, and deploying an API Gateway using an OpenAPI Specification template.
- **Source Code**: Access all the configurations and scripts on the [GitHub repository](https://github.com/etorralba/serverless-terraform-lambda).
### **Setting Up Your Lambda Functions**
To begin, ensure you have a well-organized directory and an initialized npm project:
1. **Create Your Directory Structure**: Maintaining an organized project structure is essential for efficiently managing your Lambda handlers and shared modules. Here’s a recommended setup:
```
├── scripts
│ └── build.sh
├── lambda_handlers
│ ├── function1.ts
│ └── function2.ts
├── package-lock.json
├── package.json
├── Makefile
├── tsconfig.json
└── src
└── test_function.ts
```
2. **Initialize the npm Project**: Run `npm init` to initiate your npm project. This will create your project's package.json and prepare it for adding dependencies.
3. **Install Dependencies**: Install the required packages for your project:
```bash
npm install base-64
npm install --save-dev aws-lambda esbuild typescript @types/node ts-node @types/base-64 @types/aws-lambda
```
### **Lambda Function Handlers**
Next, let's explore two straightforward TypeScript Lambda functions designed to process requests:
```typescript
// lambda_handlers/function1.ts
import {
APIGatewayProxyEventV2,
APIGatewayProxyStructuredResultV2,
} from "aws-lambda";
import base64 from "base-64";
import { printValue } from "../src/test_function";
// Define the Lambda handler function
export const handler = async (
event: APIGatewayProxyEventV2
): Promise<APIGatewayProxyStructuredResultV2> => {
const body = JSON.parse(base64.decode(event.body!));
printValue(body);
return {
statusCode: 200,
body: JSON.stringify({
message: "This is function1",
}),
};
};
```
```typescript
// lambda_handlers/function2.ts
import {
APIGatewayProxyEventV2,
APIGatewayProxyStructuredResultV2,
} from "aws-lambda";
import base64 from "base-64";
import { printValue } from "../src/test_function";
export const handler = async (
event: APIGatewayProxyEventV2
): Promise<APIGatewayProxyStructuredResultV2> => {
const body = JSON.parse(base64.decode(event.body!));
printValue(body);
return {
statusCode: 200,
body: JSON.stringify({
message: "This is function2",
}),
};
};
```
```ts
// src/test_function.ts
// Function to log any value to the console
export const printValue = (value: any) => {
console.log(value);
}
```
### **Building and Zipping Lambda Functions**
For deployment, use `esbuild` to compile and zip your TypeScript files:
```json
"scripts": {
"build:function1": "esbuild lambda_handlers/function1.ts --bundle --outdir=dist --platform=node && cd ./dist && zip -r function1.zip function1.js",
"build:function2": "esbuild lambda_handlers/function2.ts --bundle --outdir=dist --platform=node && cd ./dist && zip -r function2.zip function2.js"
},
```
A bash script can automate the building process for all functions, ensuring efficient and error-free builds:
```bash
#!/bin/bash
# Build script to automate the compilation and zipping of Lambda functions
npm install
mkdir -p dist
cd lambda_handlers
for file in *.ts; do
npx esbuild $file --bundle --platform=node --outfile=../dist/${file%.*}.js
cd ../dist
zip -r ${file%.*}.zip ${file%.*}.js
rm ${file%.*}.js
cd ../lambda_handlers
done
```
- `chmod +x scripts/build.sh` to allow executing permissons to the Bash script.
### **Setting Up Terraform for Serverless**
Now, configure a basic Terraform setup to manage your infrastructure effectively:
```
├── terraform
├── templates
│ └── openapi.tpl.yml
├── main.tf
├── providers.tf
├── variables.tf
└── output.tf
```
Use the following configuration to define your provider and backend:
```hcl
# providers.tf
// Define the required providers and configure the AWS provider
terraform {
required_providers {
aws = {
source = "hashicorp/aws"
version = "~> 5.0"
}
}
}
provider "aws" {
profile = "default"
region = var.region
}
```
Define the variables required for your infrastructure:
```hcl
# variables.tf
// Define variables for the AWS region and Lambda function filenames
variable "region" {
description = "The region where the resources will be provisioned"
type = string
default = "us-east-1"
}
variable "file_names" {
description = "The file names of the Lambda functions"
type = list(string)
}
```
Set up CloudWatch Log Groups, IAM Policies, and roles for each Lambda to ensure secure and compliant logging and execution permissions:
```hcl
# main.tf
// Define CloudWatch Log Groups
resource "aws_cloudwatch_log_group" "loggroup" {
for_each = toset(var.file_names)
name = "/aws/lambda/${each.key}"
retention_in_days = 14
}
// IAM Policies for each Lambda to write to their respective Log Group
resource "aws_iam_policy" "logs_role_policy" {
for_each = toset(var.file_names)
name = "${each.key}-logs"
policy = data.aws_iam_policy_document.logs_role_policy[each.key].json
}
data "aws_iam_policy_document" "logs_role_policy" {
for_each = toset(var.file_names)
statement {
effect = "Allow"
actions = [
"logs:CreateLogStream",
"logs:PutLogEvents"
]
resources = [
aws_cloudwatch_log_group.loggroup[each.key].arn
]
}
}
// IAM Role for each Lambda Function
resource "aws_iam_role" "main" {
for_each = toset(var.file_names)
name = "iam-${each.key}"
assume_role_policy = data.aws_iam_policy_document.assume_role.json
}
data "aws_iam_policy_document" "assume_role" {
statement {
effect = "Allow"
principals {
type = "Service"
identifiers = ["lambda.amazonaws.com"]
}
actions = ["sts:AssumeRole"]
}
}
// Attach Logging Policies to each IAM Role
resource "aws_iam_role_policy_attachment" "logging_attachment" {
for_each = toset(var.file_names)
role = aws_iam_role.main[each.key].id
policy_arn = aws_iam_policy.logs_role_policy[each.key].arn
}
// Define the Lambda Functions in Terraform, specifying code, execution role, and settings
resource "aws_lambda_function" "handler" {
for_each = toset(var.file_names)
filename = "../dist/${each.key}.zip"
source_code_hash = filebase64sha256("../dist/${each.key}.zip")
function_name = each.key
role = aws_iam_role.main[each.key].arn
handler = "index.handler"
timeout = 20
runtime = "nodejs20.x"
}
```
### **Setting Up Terraform for API Gateway**
Create the templates directory under the terraform folder.
```
├── terraform
├── templates
└── openapi.tpl.yml
```
Then, create an OpenAPI Specification file template to define how your API Gateway interacts with the deployed Lambda functions:
```yaml
# openapi.tpl.yml
openapi: 3.0.0
info:
title: API Gateway OpenAPI Example
version: 1.0.0
paths:
%{ for lambda in lambdas ~}
/api/${lambda.function_name}:
post:
operationId: Invoke-${lambda.function_name}
x-amazon-apigateway-integration:
uri: ${lambda.invoke_arn}
responses:
default:
statusCode: "200"
passthroughBehavior: "when_no_match"
httpMethod: "POST"
type: "aws_proxy"
responses:
'200':
description: 200 response
%{ endfor ~}
```
> **NOTE:** Keep in mind that the indentation in this file is crucial; incorrect indentation can lead to improper API Gateway creation.
Next step is to populate the OpenAPI template and pass it to the `aws_api_gateway_rest_api` resource.
```hcl
# main.tf
(...)
// API Gateway
locals {
openapi_template = templatefile("${path.module}/templates/openapi.tpl.yml", {
lambdas = aws_lambda_function.handler
region = var.region
})
}
resource "aws_api_gateway_rest_api" "main" {
name = "rest-api"
description = "REST API for Lambda functions"
binary_media_types = ["*/*"]
body = local.openapi_template
}
resource "
aws_api_gateway_deployment" "main" {
rest_api_id = aws_api_gateway_rest_api.main.id
stage_name = "prod"
}
```
Create the outputs file to display the information you want at the end of the provisioning.
```hcl
# outputs.tf
output "api_gateway_rest_api_id" {
description = "The ID of the API Gateway REST API"
value = aws_api_gateway_rest_api.main.id
}
output "api_gateway_main_resource_id" {
description = "The ID of the API Gateway main resource"
value = aws_api_gateway_rest_api.main.root_resource_id
}
```
## Create the terraform.tfvars and authenticate in aws cli
1. Create the `terraform.tfvars` like this:
```yml
region = "us-east-1"
file_names = [
"function1",
"function2"
]
```
2. Using the `aws cli`, authenticate with your access keys by running the command `aws configure`
## Apply the configuration
1. Run `make build` to build the TypeScript functions zips
2. Go to the terraform directory with `cd terraform`
3. Initialize the Terraform environment using `terraform init`
4. Make `terraform plan` to visualize the changes and resources the configuration will perform
5. Use `terraform apply` to apply the configuration and update the state.
6. When you finalize, you could destroy the resources by using the `terraform destroy` command
You should see something like this once the API Gateway is provisioned
### Further Improvements: Enhancing the Project
After completing this tutorial, there are several ways to enhance the functionality, scalability, and maintainability of the serverless architecture. These improvements can serve as challenges for developers looking to expand their expertise and further optimize the project:
1. **Add More Lambda Functions**: Explore the creation of additional Lambda functions to handle different types of requests, such as GET requests for fetching data or DELETE requests for removing records. This will provide a more comprehensive API.
2. **Implement API Caching**: Configure caching mechanisms in the API Gateway to improve response times and reduce the load on Lambda functions. This is particularly useful for endpoints that do not require real-time data.
3. **Advanced Error Handling**: Improve error handling in the Lambda functions to manage different types of exceptions more effectively. Implementing more sophisticated error logging and notifications can also help in quick debugging.
4. **Environment Variables**: Use Terraform to manage environment variables for Lambda functions, which can include database connection strings, API keys, and other sensitive information that should not be hard-coded.
5. **Database Integration**: Integrate a database with the Lambda functions. This could involve setting up a DynamoDB table with Terraform and modifying the Lambda functions to read and write data to the database.
6. **Automated Alerts and Monitoring**: Enhance monitoring and alerts using AWS CloudWatch or a third-party service. Set up alerts for function errors, high execution times, and resource limits.
7. **Security Enhancements**: Implement stricter security practices, such as more restrictive IAM roles, VPC configurations, and API authentication mechanisms. Explore the use of AWS Cognito for user authentication.
Thanks for reading! | etorralbab |
1,866,118 | Game Development Diary #11 : Second Day Back | 13/06/2024 - Thursday Today I will continue my GameDev.tv course. Here is what I’ve got from it: ... | 0 | 2024-06-13T01:30:15 | https://dev.to/hizrawandwioka/game-development-diary-11-second-day-back-59kd | gamedev, godot, godotengine, newbie | 13/06/2024 - Thursday
Today I will continue my GameDev.tv course. Here is what I’ve got from it:
##Improved Aiming and Smoothing
Vertical camera motion and using interpolate_with to smooth the camera.
##Custom Reticles
Learning how to use the _draw() virtual function and other draw functions to create custom 2D shapes for a reticle.
##Advanced Jumping
Using projectile motion to make my jumping calculations more precise.
##Making a prototyping sandbox
Using CSGShapes to fill out the play area and make a sandbox to test new features.
##Introducing Navigation
I was introduced to the NavigationServer, regions, and agents for enemy AI and navigating 3D space.
##Enemy Movement
Combining my navigation path and enemy movement script to make the enemy pursue the player.
That’s all for today. Thanks for reading my devlog.
| hizrawandwioka |
1,886,336 | Introduction to Transformer Models | NLP NLP is a field of linguistics and machine learning focused on understanding everything... | 0 | 2024-06-13T01:24:06 | https://dev.to/rohab_shabbir/introduction-to-transformer-models-1eon | machinelearning, beginners, learning |
### **NLP**
NLP is a field of linguistics and machine learning focused on understanding everything related to human language.
**What is NLP**
- Classifying whole sentences — sentiment analysis
- Classifying each word in a sentence — grammatically
- Generating text content — auto generated text
**Transformers and NLP**
Transformers are game-changers in NLP. Unlike traditional models, they excel at understanding connections between words, no matter the distance. This "attention" allows them to act like language experts, analyzing massive amounts of text to perform tasks like translation and summarization with impressive accuracy. We'll explore how these transformers work next!
### **Transformers**
These are basically models that can do almost every task of NLP; some are mentioned below. The most basic object that can do these tasks is pipeline() function.
**Sentiment analysis**
It can classify sentences that are positive or negative.
0.999… score tells that machine is confident about this 99%.
We can also pass several sentences, score for each will be provided.
By default, this pipeline selects a particular pretrained model that has been fine-tuned for sentiment analysis in English. The model is downloaded and cached when we create the classifier object
**Zero-shot classification**
It allows us to label the data which we want instead of relying the data labels in the models.
**Text generation**
The main idea about text generation is we’ll provide some text and it will generate text. We can also control the total length of output text.
If we don’t specify any model, it will use default model otherwise we can specify models as in above picture.
**Mask filling**
The idea of this task is to fill in the blanks
The value of k tells the number of possibility in the place of <mask>.
**Named entity recognition**
It can separate the person, organization or other things in a sentence.
- PER – person
- ORG – organization
- LOC – location
**Question answering**
It will give the answer based on provided information. It does not generate answers it just extracts the answers from the given context
**Summarization**
In this case, it will summarize the whole paragraph which we will provide.
**Translation**
It will translate your provide text into different languages.
I have provided model name as well as translation languages “en-ur” English to Urdu.
###How transformers work?
The architecture was introduced in 2018, some influential models are GPT, BERT etc.
The transformer models are basically language models, meaning they have been trained on large amounts of raw text in a self-supervised fashion. **Self supervised learning** means that humans are not needed to label the data. It is not useful for specific practical tasks so in that case we use **Transfer Learning**. It is transferring knowledge of specific model to other model for other specific task.
Transformers are large models, to achieve better results, the models should be trained on large data but training on large data impacts environment heavily due to emission of carbon dioxide.
So instead of **pretraining**(training of model from scratch) we **finetune the existing models**(using pretraining models) in order to reduce time, effects on environment.
Fine-tuning a model therefore has lower time, data, financial, and environmental costs. It is also quicker and easier to iterate over different fine-tuning schemes, as the training is less constraining than a full pretraining.
**General Architecture**
It generally consists of 2 sections
- Encoders
- Decoders
<u>Encoders</u> receive input and builds representation of its features.
<u>Decoders</u> uses the above representation and gives output.
**Models**
There 3 types of models
- Only encoders — these are good for tasks that require
understanding of input such as name or entity recognition etc.
- Only decoders — these are good for generative tasks.
- Both encoders and decoders — these are good for generative tasks that need input such as summarization or translation.
###ENCODERS
The architecture of BERT(the most popular model) is “encoder only”.
**How does it actually works**
It takes input of certain words then generate a sequence (numerical, feature vector) for these words.
The numerical values generated for each word is not just value of that word but the numerical value or sequence is generated depending upon context of the sentence (Self attention mechanism), from left and right in sentence.(bi-directional)
**When encoders can be used**
- Classifications tasks
- Question answering tasks
- Masked language modeling
In these tasks Encoders really shine.
**Representatives of this family**
- ALBERT
- BERT
- DistilBERT
- ELECTRA
- RoBERTa
###DECODERS
We can do similar tasks with decoders as in encoders with a little bit loss of performance.
The difference between Encoders and decoders is that encoders uses self attention mechanism while decoders use a masked self attention mechanism, that is it generates sequence for a word independently of its context.
**When we should use a decoder**
- Text generation (ability to generate text, a word or a known sequence of words in NLP is called casual language modeling)
- Word prediction
At each stage, for a given word the attention layers can only access the words positioned before it in the sentence. These models are often called auto-regressive models.
**Representatives of this family**
- CTRL
- GPT
- GPT-2
- Transformer XL
###ENCODER-DECODER
In these type of models, we use encoder alongside with decoder.
**Working**
Let’s take an example of translation (transduction)
We give a sentence as input to encoder, it generates some numerical sequence for those words and then these words are taken as input by decoder. Decoder decodes the sequence and output a word. The start of sequence word indicates that it should start decoding the words. When we get the first word and feature vector(sequence generated by encoder), encoder is no more needed.
We have learnt about auto regressive manner of decoder. So, the word it output can now be used as its input to generate 2nd word. It will goes on until the sequence is finished.
In this model, encoder takes care of understanding the sequence and decoder takes care about generation of output based on understanding of encoder.
**Where we can use these**
- Translation
- Summarization
- generative question answering
**Representatives of this family**
- BART
- mBART
- Marian
- T5
**Limitations**
Important note at the end of article is that if you want to use pretrain the model or finetune model, while these models are powerful but comes with limitations.
While requiring a mask for above data it gives these possible words gender specific. So if you are using any of these models this can be an issue.
**Conclusion**
In conclusion, transformer models have revolutionized the field of NLP. Their ability to understand relationships between words and handle long sequences makes them powerful tools for a wide range of tasks, from translation and text summarization to question answering and text generation. While the technical details can be complex, hopefully, this introduction has given you a basic understanding of how transformers work and their potential impact on the future of human-computer interaction.
| rohab_shabbir |
1,886,344 | Commodity Futures High Frequency Trading Strategy written by C++ | Summary The market is the battleground, the buyer and the seller are always in the game,... | 0 | 2024-06-13T01:22:21 | https://dev.to/fmzquant/commodity-futures-high-frequency-trading-strategy-written-by-c-2o2b | trading, strategy, cryptocurrency, fmzquant | ## Summary
The market is the battleground, the buyer and the seller are always in the game, which is also the eternal theme of the trading business. The Penny Jump strategy shared today is one of high-frequency strategies, originally derived from the interbank foreign exchange market, and is often used in mainstream fait currency pairs.
## High frequency strategy classification
In high-frequency trading, there are two main types of strategies. The buyer side strategy and the seller side strategy. The seller side strategy is usually a market-making strategy, and the these two side of strategies are opponents. For example, the high-frequency arbitrage buyer strategy of smoothing all unreasonable phenomena in the market at the fastest speed, taking the initiative to attack price quickly, or eating the wrong price of other market makers.
There is also a way to analyze the historical data or the ordering rules of the market, to send the pending orders at an unreasonable price in advance, and to send the withdrawal orders with the rapid change of the market price. Such strategies are common in passive market making, once the pending orders are executed, And after a certain profit or after reaching the stop-loss condition, the position will be closed. Passive market-making strategies usually do not require too much speed, but it requires a strong strategy logic and structure.
## What is the Penny Jump strategy?
Penny Jump translates into English is the meaning of micro-price increase. The principle is to track the buying price and the selling price of the market. Then, according to the price of the market, plus or minus the micro-price increase of the tracking price, it is obvious that this is a passive trading strategy, it is belong to the seller side market-making strategy. Its business model and logic are to conduct bilateral transactions on exchange-listed limit orders to provide liquidity.
The market-making strategy requires a certain amount of inventory in hand, and then trades both at the buyer and seller side. The main income of this strategy is the commission fee return provided by the exchange, as well as the price difference earned by buying low and selling high. But for many high-frequency traders who want to market making, earning a bid-ask spread is a good thing, but it is not an absolute means of profit.
## Penny Jump strategy principle
We know that there are many retail investors in the trading market, and there are also many large investors, such as: "hot money", public funds, private funds, and so on. Retail investors usually have less funds, their orders has very small impact in the market, they can easily buy and sell a trading target at any time. But for large funds to participate the market, it is not that simple.
If a large investor wants to buy 500 lots of crude oil, there are not so many orders at the current price for sell, and the investor don't want to buy them at the higher price. If they insist on send the buying order at current price, The cost of slippage points will be too much. therefore, it has to send a pending order at the desired price. All the participants in the market will see a hugh buying order showing on the certain price.
Because of this huge order, it looks clumsy in the market, sometimes we call it "elephant orders". For example, the current market showing:
```
Selling Price 400.3, Order volume 50; buying price 400.1, Order volume 10.
```
Suddenly this cumbersome elephant jump into the market, and the bid price was sent at the price of 400.1. At this time, the market becomes:
```
Selling Price 400.3, Order volume 50; Buying price 400.1, Order volume 510.
```
Traders all know that if there is a huge amount of pending orders at certain price, then this price will form a strong support(or resistance). Futhermore, high frequency traders also know, if they send a buying order above the "Buying 1" price in the order book depth, then the market becomes:
```
Selling Price 400.3, Order volume 50; Buying price 400.2, Order volume 1,
```
The price 400.1 becomes "Buying 2" price in the order book depth. Then if the price rises to 400.3, the high-frequency trader will earn a profit of 0.1.
Even if the price does not rise, in the position of "buying 2", there still has an "elephant" holding the price, and it can be quickly sold back to the elephant at price 400.1. This is the general idea of Penny Jump strategy. Its logic is as simple as this, by monitoring the market order status, to speculate the opponent's intentions, and then to take the lead in building a favorable position, and finally profit from a small spread in a short period of time. For this "elephant", because he hangs a huge amount of buying order in the market, he exposed his trading intentions, and naturally became the hunted target of high-frequency traders.
## "Penny Jump" strategy implementation
First, observe the trading opportunities with very low probability of the market, and make corresponding strategies according to the trading logic. If the logic is complex, you need to use the existing mathematical knowledge, use the model to describe the nature of the irrational phenomenon as much as possible, and minimize the overfitting. In addition, it must be verified by a backtest engine that can meet the "Price first then Volume first" principle. Luckily, we have FMZ Quant platform that currently supports this backtesting modes.
What is the meaning of supporting "Price first then Volume first" backtest engine? You can understand it as: you send a pending order at 400.1 to buy, only when the selling price in order book depth is 400.1 or lower, your pending order can be closed(executed). It only calculates the price data of the pending orders, and does not calculate the volume data of pending orders, which only meets the price priority(price first) in the exchange orders matching rules.
The "Volume first" is an upgraded version of the "price first". It is both price-prioritized and time-first. It can be said that this matching mode is exactly the same as the exchange model. By calculating the amount of the pending order, it is judged whether the current pending order reaches the condition of passive transaction to realize the volume transaction, so as to achieve a real simulation of the real market environment.
In addition, some readers may find that the Penny Jump strategy requires market trading opportunities, that is, the market need has at least two "hop" price gaps. Under normal circumstances, the main trading contract of commodity futures is relatively "busy". The difference between "Buying 1" and "Selling 1" hop is that there is almost no trading chance. So we put our energy on the sub-primary contract where the trading is not too active. This type of trading contract occasionally has two or even three "hop" opportunities. For example, in the MA ("Methanol" code in Chinese commodity futures) 1909 contract, the following situation occurs:
"Selling 1" price 2225 with volume 551, "Buying 1" price 2223 with volume 565, look down for a few seconds. After this happens, it will disappear after several ticks. In this case, we regard the market as self-correction. What we have to do is to catch up. Before the market actively corrects it. if we do it by manually, it would be impossible, with the help of automatic trading, we can make it possible.
The two "hop" price gap appearance situation happens very often, but the three hops are the safest, but the three hops rarely occur, resulting in trading frequency is too low.
Next, we observe the difference between the pervious "Selling 1" "Buying 1" and the "Buying 1" "Selling 1" now. In order to fill the price gap between the market, if the speed is fast enough, it can be placed at the forefront of other orders. Also, the position holding time is very short, with this trading logic, after the realization of the strategy, take the MA909 as an example, the real market test recommends Esunny instead of the CTP interface, the mechanism of position and fund changing situation for Esunny is by pushed data, very suitable for high frequency trading.
## Strategy code
After clearing the trading logic, we can use the code to achieve it. Since the FMZ Quant platform use C++ writing strategy examples are too few, here we use C++ to write this strategy, which is convenient for everyone to learn, and the variety is commodity futures. First open: fmz.com > Login > Dashboard > strategy library > New Strategy > Click the drop-down menu in the top left corner > Select C++ to start writing the strategy, pay attention to the comments in the code below.
- Step 1: First build the framework of the strategy, in which a HFT class and a main function are defined. The first line in the main function is to clear the log. The purpose of this is to clear the previously running log information every time the strategy is restarted. The second line is to filter some error messages that are not necessary, such as network delay and some tips appear, so that the log only records important information and looks more neat; the third line is to print the "Init OK" message, meaning that the program has started to start. the fourth line is to create an object according to the HFT class, and the object name is hft; the fifth line program enters the while loop, and always executes the loop in the object hft Method, it can be seen that the Loop method is the core logic of this program. Line 6 is another print message. Under normal circumstances, the program will not execute to line 6. If the program is executed to line 6, the proof program has ended.
Next, let's look at the HFT class, which has five methods. The first method is the construction method; the second method is to obtain the current day of the week to determine whether it is a new K line; the third method is mainly to cancel all unfilled orders, and get detailed Position information, because before the order is placed, it must first determine the current position status; the fourth method is mainly used to print some information, for this strategy, this method is not the main one; the most important is the fifth method, This method is mainly responsible for processing trading logic and placing orders.
```
/ / Define the HFT class
Class HFT {
Public:
HFT() {
// Constructor
}
Int getTradingWeekDay() {
// Get the current day of the week to determine if it is a new K line
}
State getState() {
/ / Get order data
}
Void stop() {
// Print orders and positions
}
Bool Loop() {
// Strategy logic and placing orders
}
};
// main function
Void main() {
LogReset(); // clear the log
SetErrorFilter("ready|timeout"); // Filter error messages
Log("Init OK"); // Print the log
HFT hft; // Create HFT object
While (hft.Loop()); // enter loop
Log("Exit"); // Program exits, prints the log
}
```
So let's see how each of the methods in this HFT class is implemented, and how the most core Loop method works. From top to bottom, we will implement the specific implementation of each method one by one, and you will find that the original high frequency strategy is so simple. Before talking about the HFT class, we first defined several global variables for storing the results of the hft object calculation. They are: storing order status, position status, holding long position, holding short position, buying price, buying quantity, selling price, selling quantity. Please see the code below:
```
/ / Define the global enumeration type State
Enum State {
STATE_NA, // store order status
STATE_IDLE, // store position status
STATE_HOLD_LONG, // store long position directions
STATE_HOLD_SHORT, // store short position direction
};
/ / Define global floating point type variable
Typedef struct {
Double bidPrice; // store the buying price
Double bidAmount; // store the buying amount
Double askPrice; // store the selling price
Double askAmount; // store the selling amount
} Book;
```
With the above global variables, we can store the results calculated by the hft object separately, which is convenient for subsequent calls by the program. Next we will talk about the specific implementation of each method in the HFT class. First, the first HFT method is a constructor that calls the second getTradingWeekDay method and prints the result to the log. The second getTradingWeekDay method gets the current day of the week to determine if it is a new K line. It is also very simple to implement, get the timestamp, calculate the hour and week, and finally return the number of weeks; the third getState method is a bit long, i will just describe the general idea, for specific explanation, you can look at the comments in the following coding block.
Next, let's get all the orders first, return the result is a normal array, then traverse this array, one by one to cancel the order, then get the position data, return an array, and then traverse this Array, get detailed position information, including: direction, position, yesterday or current position, etc., and finally return the result; the fourth stop method is to print information; the code is as follows:
```
Public:
// Constructor
HFT() {
_tradingDay = getTradingWeekDay();
Log("current trading weekday", _tradingDay);
}
// Get the current day of the week to determine if it is a new K line
Int getTradingWeekDay() {
Int seconds = Unix() + 28800; // get the timestamp
Int hour = (seconds/3600)%24; // hour
Int weekDay = (seconds/(60*60*24))%7+4; // week
If (hour > 20) {
weekDay += 1;
}
Return weekDay;
}
/ / Get order data
State getState() {
Auto orders = exchange.GetOrders(); // Get all orders
If (!orders.Valid || orders.size() == 2) { // If there is no order or the length of the order data is equal to 2
Return STATE_NA;
}
Bool foundCover = false; // Temporary variable used to control the cancellation of all unexecuted orders
// Traverse the order array and cancel all unexecuted orders
For (auto &order : orders) {
If (order.Id == _coverId) {
If ((order.Type == ORDER_TYPE_BUY && order.Price < _book.bidPrice - _toleratePrice) ||
(order.Type == ORDER_TYPE_SELL && order.Price > _book.askPrice + _toleratePrice)) {
exchange.CancelOrder(order.Id, "Cancel Cover Order"); // Cancel order based on order ID
_countCancel++;
_countRetry++;
} else {
foundCover = true;
}
} else {
exchange.CancelOrder(order.Id); // Cancel order based on order ID
_countCancel++;
}
}
If (foundCover) {
Return STATE_NA;
}
// Get position data
Auto positions = exchange.GetPosition(); // Get position data
If (!positions.Valid) { // if the position data is empty
Return STATE_NA;
}
// Traverse the position array to get specific position information
For (auto &pos : positions) {
If (pos.ContractType == Symbol) {
_holdPrice = pos.Price;
_holdAmount = pos.Amount;
_holdType = pos.Type;
Return pos.Type == PD_LONG || pos.Type == PD_LONG_YD ? STATE_HOLD_LONG : STATE_HOLD_SHORT;
}
}
Return STATE_IDLE;
}
// Print orders and positions information
Void stop() {
Log(exchange.GetOrders()); // print order
Log(exchange.GetPosition()); // Print position
Log("Stop");
}
```
Finally, we focus on how the Loop function controls the strategy logic and the order. If you want to see more carefully, you can refer to the comments in the code. First determine whether the CTP transaction and the market server are connected; then obtain the available balance of the account and obtain the number of weeks; then set the variety code to be traded, by calling the FMZ Quant official SetContractType function, and can use this function to return the details of the trading variety; then call the GetDepth function to get the depth data of the current market. The depth data includes: buying price, buying volume, selling price, selling volume, etc., and we store them with variables, because they will be used later; Then output these port data to the status bar to facilitate the user to view the current market status; the code is as follows:
```
// Strategy logic and placing order
Bool Loop() {
If (exchange.IO("status") == 0) { // If the CTP and the quote server are connected
LogStatus(_D(), "Server not connect ...."); // Print information to the status bar
Sleep(1000); // Sleep 1 second
Return true;
}
If (_initBalance == 0) {
_initBalance = _C(exchange.GetAccount).Balance; // Get account balance
}
Auto day = getTradingWeekDay(); // Get the number of weeks
If (day != _tradingDay) {
_tradingDay = day;
_countCancel = 0;
}
// Set the futures contract type and get the contract specific information
If (_ct.is_null()) {
Log(_D(), "subscribe", Symbol); // Print the log
_ct = exchange.SetContractType(Symbol); // Set futures contract type
If (!_ct.is_null()) {
Auto obj = _ct["Commodity"]["CommodityTickSize"];
Int volumeMultiple = 1;
If (obj.is_null()) { // CTP
Obj = _ct["PriceTick"];
volumeMultiple = _ct["VolumeMultiple"];
_exchangeId = _ct["ExchangeID"];
} else { // Esunny
volumeMultiple = _ct["Commodity"]["ContractSize"];
_exchangeId = _ct["Commodity"]["ExchangeNo"];
}
If (obj.is_null() || obj <= 0) {
Panic("PriceTick not found");
}
If (_priceTick < 1) {
exchange.SetPrecision(1, 0); // Set the decimal precision of the price and the quantity of the order.
}
_priceTick = double(obj);
_toleratePrice = _priceTick * TolerateTick;
_ins = _ct["InstrumentID"];
Log(_ins, _exchangeId, "PriceTick:", _priceTick, "VolumeMultiple:", volumeMultiple); // print the log
}
Sleep(1000); // Sleep 1 second
Return true;
}
// Check orders and positions to set status
Auto depth = exchange.GetDepth(); // Get depth data
If (!depth.Valid) { // if no depth data is obtained
LogStatus(_D(), "Market not ready"); // Print status information
Sleep(1000); // Sleep 1 second
Return true;
}
_countTick++;
_preBook = _book;
_book.bidPrice = depth.Bids[0].Price; // "Buying 1" price
_book.bidAmount = depth.Bids[0].Amount; // "Buying 1" amount
_book.askPrice = depth.Asks[0].Price; // "Selling 1" price
_book.askAmount = depth.Asks[0].Amount; // "Selling 1" amount
// Determine the state of the port data assignment
If (_preBook.bidAmount == 0) {
Return true;
}
Auto st = getState(); // get the order data
// Print the port data to the status bar
LogStatus(_D(), _ins, "State:", st,
"Ask:", depth.Asks[0].Price, depth.Asks[0].Amount,
"Bid:", depth.Bids[0].Price, depth.Bids[0].Amount,
"Cancel:", _countCancel,
"Tick:", _countTick);
}
```
After done so much, we can finally placing orders. Before the trading, first we judge the current holding position status of the program (no holding position, long position orders, short position orders), here we used the if...else if...else if logic control. They are very simple, If there is no holding position, the position will be opened according the logic condition. If there is holding position, the position will closed according the logic condition. In order to facilitate everyone's understanding, we use three paragraphs to explain the logic, For opening position part:
First declare a Boolean variable, we use it to control the closing position; next we need get the current account information, and record the profit value, then determine the status of the withdrawal order, if the number of withdrawal exceeds the set maximum, print the related information in the log; then calculate the absolute value of the current bid and offer price difference to determine whether there is more than 2 hops between the current bid price and the ask price.
Next, we get the "Buying 1" price and "Selling 1" price, if the previous buying price is greater than the current buying price, and the current selling volume is less than the buying volume, it means that "Buying 1" price is disappeared. the long position opening price and the order quantity are set; otherwise, if the previous selling price is less than the current selling price, and the current buying volume is less than The selling volume proves that the "Selling 1" price is disappeared, the short position opening price and the order quantity are set; in the end, the long position and the short position orders enter the market at the same time. The specific code is as follows:
```
Bool forceCover = _countRetry >= _retryMax; // Boolean value used to control the number of closings
If (st == STATE_IDLE) { // if there is no holding position
If (_holdAmount > 0) {
If (_countRetry > 0) {
_countLoss++; // failure count
} else {
_countWin++; // success count
}
Auto account = exchange.GetAccount(); // Get account information
If (account.Valid) { // If get account information
LogProfit(_N(account.Balance+account.FrozenBalance-_initBalance, 2), "Win:", _countWin, "Loss:", _countLoss); // Record profit value
}
}
_countRetry = 0;
_holdAmount = 0;
// Judging the status of withdrawal
If (_countCancel > _cancelMax) {
Log("Cancel Exceed", _countCancel); // Print the log
Return false;
}
Bool canDo = false; // temporary variable
If (abs(_book.bidPrice - _book.askPrice) > _priceTick * 1) { // If there is more than 2 hops between the current bid and ask price
canDo = true;
}
If (!canDo) {
Return true;
}
Auto bidPrice = depth.Bids[0].Price; // Buying 1 price
Auto askPrice = depth.Asks[0].Price; // Selling 1 price
Auto bidAmount = 1.0;
Auto askAmount = 1.0;
If (_preBook.bidPrice > _book.bidPrice && _book.askAmount < _book.bidAmount) { // If the previous buying price is greater than the current buying price and the current selling volume is less than the buying volume
bidPrice += _priceTick; // Set the opening long position price
bidAmount = 2; // set the opening long position volume
} else if (_preBook.askPrice < _book.askPrice && _book.bidAmount < _book.askAmount) { // If the previous selling price is less than the current selling price and the current buying volume is less than the selling volume
askPrice -= _priceTick; // set the opening short position volume
askAmount = 2; // set the opening short position volume
} else {
Return true;
}
Log(_book.bidPrice, _book.bidAmount, _book.askPrice, _book.askAmount); // Print current market data
exchange.SetDirection("buy"); // Set the order type to buying long
exchange.Buy(bidPrice, bidAmount); // buying long and open position
exchange.SetDirection("sell"); // Set the order type to selling short
exchange.Sell(askPrice, askAmount); // short sell and open position
}
```
Next, we will talk about how to close long position, first set the order type according to the current position status, and then get the "Selling 1" price. If the current "Selling 1" price is greater than the buying long opening price, set the closing long position price. If the current "selling 1" price is less than the long position opening price, then reset closing quantity variable to true, then close all long position. Coding part as below:
```
Else if (st == STATE_HOLD_LONG) { // if holding long position
exchange.SetDirection((_holdType == PD_LONG && _exchangeId == "SHFE") ? "closebuy_today" : "closebuy"); // Set the order type, and close position
Auto sellPrice = depth.Asks[0].Price; // Get "Selling 1" price
If (sellPrice > _holdPrice) { // If the current "selling 1" price is greater than the long position opening price
Log(_holdPrice, "Hit #ff0000"); // Print long position opening price
sellPrice = _holdPrice + ProfitTick; // Set closing long position price
} else if (sellPrice < _holdPrice) { // If the current "selling 1" price is less than the long position opening price
forceCover = true;
}
If (forceCover) {
Log("StopLoss");
}
_coverId = exchange.Sell(forceCover ? depth.Bids[0].Price : sellPrice, _holdAmount); // close long position
If (!_coverId.Valid) {
Return false;
}
}
```
Finally, let's see how to close short position. The principle is the opposite of the above-mentioned closing long position. First, according to the current position status, set the order type, and then get the "Buying 1" price, if the current "buying 1" price is less than the short position opening price, the price of the closing short position will be set. If the current "buying 1" price is greater than the opening short position price, reset closing quantity variable to true, then close all short position.
```
Else if (st == STATE_HOLD_SHORT) { // if holding short position
exchange.SetDirection((_holdType == PD_SHORT && _exchangeId == "SHFE") ? "closesell_today" : "closesell"); // Set the order type, and close position
Auto buyPrice = depth.Bids[0].Price; // Get "buying 1" price
If (buyPrice < _holdPrice) { // If the current "buying 1" price is less than the opening short position price
Log(_holdPrice, "Hit #ff0000"); // Print the log
buyPrice = _holdPrice - ProfitTick; // Set the close short position price
} else if (buyPrice > _holdPrice) { // If the current "buying 1" price is greater than the opening short position price
forceCover = true;
}
If (forceCover) {
Log("StopLoss");
}
_coverId = exchange.Buy(forceCover ? depth.Asks[0].Price : buyPrice, _holdAmount); // close short position
If (!_coverId.Valid) {
Return false;
}
}
```
The above is a complete analysis of this strategy. Click here (https://www.fmz.com/strategy/163427) to copy the complete strategy source code without configuring backtest environment on FMZ Quant.
## Backtest results
## Trading logic
## Strategy statement
In order to satisfy the curiosity of high-frequency trading and to see the results more clearly, this strategy backtest environment transaction fee is set to 0, which leads to a simple fast speed logic. if you want to cover the transaction fee to achieve profitability in the real market. More optimization is needed. Such as using the order stream to carry out short-term forecasting to improve the winning rate, plus the exchange fee refund, In order to achieve a sustainable profitable strategy, there are many books on high-frequency trading. I hope that everyone can think more and go to the real market instead of just staying on the principle.
## About us
FMZ Quant is a purely technology-driven team that provides a highly efficient available backtest mechanism for quantitative trading enthusiasts. Our backtest mechanism is simulating a real exchange, rather than a simple price match. We hope users can take advantage of the platform to better play their own abilities.
From: https://blog.mathquant.com/2020/05/22/commodity-futures-high-frequency-trading-strategy-written-by-c.html | fmzquant |
1,886,340 | AI to the world Care | This is a submission for the Twilio Challenge What I Built Demo ... | 0 | 2024-06-13T01:18:46 | https://dev.to/stromlight/ai-to-the-world-care-2lmj | devchallenge, twiliochallenge, ai, twilio | *This is a submission for the [Twilio Challenge ](https://dev.to/challenges/twilio)*
## What I Built
<!-- Share an overview about your project. -->
## Demo
<!-- Share a link to your app and include some screenshots here. -->
## Twilio and AI
<!-- Tell us how you leveraged Twilio’s capabilities with AI -->
## Additional Prize Categories
<!-- Does your submission qualify for any additional prize categories (Twilio Times Two, Impactful Innovators, Entertaining Endeavors)? Please list all that apply. -->
<!-- Team Submissions: Please pick one member to publish the submission and credit teammates by listing their DEV usernames directly in the body of the post. -->
<!-- Don't forget to add a cover image (if you want). -->
<!-- Thanks for participating! → | stromlight |
1,886,335 | Cloud deployment models | public Quick access to computing resources without a large upfront cost, with the public... | 0 | 2024-06-13T01:11:09 | https://dev.to/leonardosantosbr/cloud-deployment-models-368b | ## public
Quick access to computing resources without a large upfront cost, with the public cloud, your company purchases virtualized computing, storage, and networking services from a cloud service provider over the public internet.
## private
A private cloud is hosted in a data center and maintained by IT staff, this involves significant capital expenditure. Having your own private cloud also allows you to control how data is shared and stored. This is often the best option if cloud security is a concern, as you can manage data governance.
## multicloud
By combining services from different cloud service offerings, multicloud offers more flexibility across different price points, service offerings, features and geographic locations.
## hybrid
combines public cloud and private cloud environments, allowing data and applications to be shared between them. | leonardosantosbr | |
1,886,334 | Real-Time Communication with WebSockets: A Complete Guide | Unlock the power of WebSockets for real-time communication in web applications. This complete guide... | 0 | 2024-06-13T01:07:02 | https://dev.to/dipakahirav/real-time-communication-with-websockets-a-complete-guide-32g4 | javascript, webdev, websocket, programming | Unlock the power of WebSockets for real-time communication in web applications. This complete guide covers everything from the basics to advanced features, helping you implement efficient, scalable, and real-time updates in your projects. Perfect for developers aiming to master WebSocket technology.
please subscribe to my [YouTube channel](https://www.youtube.com/@DevDivewithDipak?sub_confirmation=1
) to support my channel and get more web development tutorials.
**Introduction**
WebSockets provide a full-duplex communication channel over a single, long-lived connection between the client and the server. This technology is essential for applications that require real-time updates, such as chat applications, live notifications, and online gaming. In this comprehensive guide, we will explore the concept of WebSockets, understand their benefits, and learn how to implement them in your projects effectively.
## What Are WebSockets?
WebSockets are a protocol for creating a persistent connection between a client and a server. Unlike HTTP, which follows a request-response model, WebSockets allow for continuous two-way communication, enabling real-time data transfer.
**Example Use Cases:**
- Real-time chat applications
- Live sports scores
- Collaborative editing tools
- Online gaming
## Why Use WebSockets?
1. **Real-Time Communication**: WebSockets allow for instant data exchange, which is critical for real-time applications.
2. **Efficiency**: By maintaining a single open connection, WebSockets reduce the overhead of multiple HTTP requests.
3. **Scalability**: WebSockets can handle thousands of concurrent connections, making them suitable for large-scale applications.
## How Do WebSockets Work?
WebSockets start as an HTTP connection and then upgrade to a WebSocket connection through a process known as the WebSocket handshake. Once established, the connection remains open, allowing for continuous data exchange.
### WebSocket Handshake
The WebSocket handshake involves the following steps:
1. The client sends an HTTP request to the server with an `Upgrade` header indicating a request to switch to the WebSocket protocol.
2. The server responds with an HTTP 101 status code if it agrees to upgrade.
3. The WebSocket connection is established, enabling full-duplex communication.
## Implementing WebSockets in JavaScript
### Setting Up the Server
To set up a WebSocket server, you can use Node.js with the `ws` library.
**Example:**
```javascript
const WebSocket = require('ws');
const server = new WebSocket.Server({ port: 8080 });
server.on('connection', socket => {
console.log('Client connected');
socket.on('message', message => {
console.log(`Received: ${message}`);
socket.send(`Echo: ${message}`);
});
socket.on('close', () => {
console.log('Client disconnected');
});
});
console.log('WebSocket server is running on ws://localhost:8080');
```
### Connecting from the Client
To connect to the WebSocket server from the client, you can use the WebSocket API available in modern browsers.
**Example:**
```javascript
const socket = new WebSocket('ws://localhost:8080');
socket.onopen = () => {
console.log('Connected to the server');
socket.send('Hello Server');
};
socket.onmessage = event => {
console.log(`Message from server: ${event.data}`);
};
socket.onclose = () => {
console.log('Disconnected from the server');
};
socket.onerror = error => {
console.error(`WebSocket error: ${error}`);
};
```
## Advanced WebSocket Features
### Broadcasting Messages
To broadcast a message to all connected clients, iterate through the connected clients and send the message.
**Example:**
```javascript
server.on('connection', socket => {
socket.on('message', message => {
server.clients.forEach(client => {
if (client.readyState === WebSocket.OPEN) {
client.send(message);
}
});
});
});
```
### Handling Binary Data
WebSockets can also handle binary data, making them suitable for applications like real-time video streaming.
**Example:**
```javascript
socket.binaryType = 'arraybuffer';
socket.onmessage = event => {
const binaryData = event.data;
console.log('Received binary data:', binaryData);
};
```
### Securing WebSockets
For secure communication, use `wss://` instead of `ws://` to establish a WebSocket connection over TLS/SSL.
**Example:**
```javascript
const socket = new WebSocket('wss://example.com/socket');
```
## Conclusion
WebSockets are a powerful technology for enabling real-time communication in web applications. By maintaining a persistent connection between the client and server, WebSockets allow for efficient and scalable data exchange. Implementing WebSockets in your projects can significantly enhance the user experience by providing real-time updates and interactions.
Feel free to leave your comments or questions below. If you found this guide helpful, please share it with your peers and follow me for more web development tutorials. Happy coding!
### Follow and Subscribe:
- **Website**: [Dipak Ahirav] (https://www.dipakahirav.com)
- **Email**: dipaksahirav@gmail.com
- **Instagram**: [devdivewithdipak](https://www.instagram.com/devdivewithdipak)
- **YouTube**: [devDive with Dipak](https://www.youtube.com/@DevDivewithDipak?sub_confirmation=1
)
- **LinkedIn**: [Dipak Ahirav](https://www.linkedin.com/in/dipak-ahirav-606bba128)
| dipakahirav |
1,886,333 | Mobile Bumper Repair: Convenience and Quality at Your Doorstep | Introduction In today's fast-paced world, convenience is key, and this extends to car... | 0 | 2024-06-13T00:52:12 | https://dev.to/max_silva_312126221f27e00/mobile-bumper-repair-convenience-and-quality-at-your-doorstep-10dl |
## Introduction
In today's fast-paced world, convenience is key, and this extends to car maintenance and repair. Mobile bumper repair services bring professional, high-quality repair work right to your doorstep, saving you time and hassle. This post explores the benefits of mobile bumper repair, how it works, and what to look for when choosing a service.
## The Benefits of Mobile Bumper Repair
## Convenience
One of the most significant advantages of [mobile bumper repair](https://www.bumperman.com/
) is the convenience it offers. Instead of driving to a repair shop and waiting for your car to be fixed, a technician comes to you. Whether you're at home or at work, mobile services fit into your schedule.
## Time-Saving
Mobile bumper repair services often complete repairs in a fraction of the time it would take at a traditional repair shop. This is because you don't need to wait in line, and the technician focuses solely on your vehicle.
## Cost-Effective
Without the overhead costs associated with maintaining a physical shop, mobile repair services can often offer competitive pricing. Additionally, you save on transportation costs and time away from your daily activities.
## How Mobile Bumper Repair Works
## Scheduling an Appointment
The process begins with scheduling an appointment. Most mobile repair services offer online booking, where you can provide details about your car and the damage. Some services may also offer instant quotes based on the information you provide.
## On-Site Assessment
Once an appointment is scheduled, a technician arrives at your location to assess the damage. This initial assessment ensures that they have all the necessary tools and materials to complete the repair.
## Repair Process
Depending on the extent of the damage, the technician will perform the repair on-site. This can include sanding, filling, painting, and buffing the bumper to restore it to its original condition. Mobile repair technicians are equipped with all the tools needed to perform high-quality repairs right on the spot.
## Final Inspection
After the repair is completed, the technician will perform a final inspection to ensure the quality of the work. This step ensures that the bumper looks as good as new and that all safety standards are met.
## Choosing a Mobile Bumper Repair Service
## Reputation and Reviews
When selecting a mobile bumper repair service, it's essential to check their reputation and customer reviews. Look for services with positive feedback and high ratings to ensure you receive quality work.
## Certification and Experience
Choose a service with certified technicians who have experience in bumper repair. Certification ensures that the technicians have received proper training and adhere to industry standards.
## Warranty and Guarantees
Opt for services that offer warranties or guarantees on their work. This provides peace of mind, knowing that if any issues arise after the repair, you can have them addressed without additional costs.
## Conclusion
Mobile bumper repair services offer a convenient, time-saving, and cost-effective solution for repairing vehicle damage. By bringing professional repair services to your location, these services eliminate the need for time-consuming trips to the repair shop. When choosing a mobile bumper repair service, consider factors such as reputation, certification, and warranties to ensure you receive the best possible service. Embrace the convenience and quality of mobile bumper repair and keep your vehicle looking its best with minimal disruption to your daily routine. | max_silva_312126221f27e00 | |
1,886,332 | Hello DEV Community! 👋 | Hello DEV Community! 👋 I'm thrilled to be joining this dynamic and inspiring community! My name is... | 0 | 2024-06-13T00:51:46 | https://dev.to/techgirlkaydee/hello-dev-community-4mb2 | **Hello DEV Community! 👋**
I'm thrilled to be joining this dynamic and inspiring community! My name is Khadisha, and I'm in the midst of an exciting transition from business lending to cloud engineering. Here’s a bit about my journey, my new interests, and what I hope to achieve moving forward.
**A Leap from Business Lending to Cloud Engineering**
For several years, my career revolved around business lending, where I assisted small businesses in securing the funds they needed to grow. While this work was fulfilling, I’ve always been fascinated by technology and its potential to revolutionize industries. This curiosity led me to explore cloud computing, and I quickly realized it was my true calling.
**The Journey So Far**
Transitioning from finance to tech has been challenging yet immensely rewarding. Recently, I completed a rigorous cloud engineering bootcamp that equipped me with a strong foundation in cloud technologies. In addition, I’ve pursued certifications and courses in:
- CompTIA A+
- CompTIA Network+
- CompTIA Cloud+
- Linux
- AWS
- Azure
- Kubernetes
These educational experiences have been crucial in developing my technical skills and preparing me for real-world applications.
**Embracing Golf ⛳**
As part of maintaining a balanced lifestyle during this transition, I’ve taken up golf. This new hobby has been a wonderful way to relax and challenge myself. Golf has taught me patience, focus, and the importance of incremental improvement—valuable lessons that also apply to my journey in tech.
**My Current Goals are to:**
**Deepen My Cloud Expertise:** I’m focusing on mastering AWS and Azure, working on projects that involve building and managing cloud infrastructures.
**Community Engagement:** I’m eager to connect with fellow tech enthusiasts and professionals. Sharing experiences and learning from others is something I truly value.
**Maintain Balance:** Striking a balance between my career and personal interests like golf is important to me. I strive to excel professionally while enjoying my hobbies and personal life.
**Let's Connect!**
I’m looking forward to engaging with and learning from everyone in this community. Whether you’re an experienced cloud engineer, someone transitioning to a new career like me, or simply passionate about technology, I’d love to hear your stories and advice.
Feel free to reach out to me here on DEV, or connect with me on [LinkedIn](www.linkedin.com/in/khadishadildy)/[Twitter](https://x.com/techgirlkaydee)/[GitHub](https://github.com/techgirlkaydee).
Thank you for reading, and here’s to new adventures and continuous growth! 🚀 | techgirlkaydee | |
1,886,330 | One-shot migration from Create React App to Vite | Introducing Viejct: A tool for migrating your React app from react-scripts (Create React App) to Vite. | 0 | 2024-06-13T00:49:46 | https://dev.to/bhbs/one-shot-migration-from-create-react-app-to-vite-f3 | react, vite | ---
title: One-shot migration from Create React App to Vite
published: true
description: Introducing Viejct: A tool for migrating your React app from react-scripts (Create React App) to Vite.
tags: react, vite
cover_image: https://dev-to-uploads.s3.amazonaws.com/uploads/articles/ax73j8b1q2ad92hrim37.jpeg
# published_at: 2024-06-13 00:31 +0000
---
Are you ready?
```shell
# cd <YOUR_APP>
npx viject
```
🎉
https://github.com/bhbs/viject
| bhbs |
1,886,331 | code | Python | 0 | 2024-06-13T00:49:07 | https://dev.to/mrjam/code-ojg | Python | mrjam | |
1,886,303 | Making Serverless 15x Cheaper | We’ve often heard developers working on stateful applications say that they want to adopt serverless... | 0 | 2024-06-13T00:41:35 | https://dev.to/dbos/making-serverless-15x-cheaper-751 | aws, cloud, typescript, postgres | We’ve often heard developers working on stateful applications say that they want to adopt serverless technology to more easily deploy to the cloud, but can’t because it’s prohibitively expensive. For clarity, by “stateful applications” we mean applications that manage persistent state stored in a database (for example, a web app built on Postgres).
In this blog post, we'll show how to make serverless 15x cheaper for stateful applications. First, we'll explain why it's too expensive right now. Then, we'll show how we architected the DBOS Cloud serverless platform to make serverless affordable for stateful applications.
## Improving Serverless Efficiency
The first strategy DBOS Cloud uses to make serverless efficient is sharing executors across requests to improve resource utilization. The key idea is that stateful applications are typically I/O-bound: they spend most of their time interacting with remote data stores and external services and rarely do complex computation locally.
Consider an e-commerce application that shows you the status of your latest order. When you send it a request, it calls out to a database to look up what your last order was, then waits for a response, then calls out again to look up the status of that order, then waits for a response, then finally returns the status back to you. Here’s what that might look like:
Current serverless platforms execute such applications inefficiently because they launch [every request into a separate execution environment](https://docs.aws.amazon.com/lambda/latest/dg/lambda-concurrency.html). Each execution environment sends a request to the database, then is blocked doing nothing useful until it receives the database’s response. Here’s what it looks if two people concurrently look up their latest orders in AWS Lambda:
For stateful applications, current serverless platforms spend most of their time doing nothing, then charge you for the idle time.
By contrast, DBOS Cloud multiplexes concurrent requests to the same execution environment, using the time one request spends waiting for a result from the database to serve another request. To make sure execution environments are never overloaded, DBOS Cloud continuously monitors their utilization and autoscales when needed, using [Firecracker](https://firecracker-microvm.github.io/) to rapidly instantiate new execution environments. Here’s what it looks if multiple people concurrently look up their latest orders in DBOS:
### DBOS Includes Reliable Workflow Execution
The second strategy DBOS Cloud uses is leveraging [DBOS Transact’s](https://github.com/dbos-inc/dbos-transact) reliable workflows to efficiently orchestrate multiple functions in a single application. Many applications consist of multiple discrete steps that all need to complete for the application to succeed; for example, the checkout flow for an online store might reserve inventory, then process payment, then ship the order, then send a confirmation email:
Conventional serverless platforms require an expensive external orchestrator like [AWS Step Functions](https://aws.amazon.com/step-functions/) to coordinate these steps, executing each in sequence and retrying them when they fail. By contrast, DBOS Cloud uses the reliable workflows built into open-source DBOS Transact to guarantee transactional execution for an application at no additional cost.
## DBOS Cloud vs. AWS Lambda Cost Comparison
Now that we’ve explained how DBOS Cloud achieves its cost efficiency, let’s measure it by comparing the cost to run a stateful application workload on DBOS Cloud versus AWS Lambda. We’re referencing AWS Lambda because it’s the most popular serverless platform, but the numbers are comparable for other platforms like Azure Functions or Google Cloud Functions.
Consider an application workflow with four steps. To keep the math simple, let’s say each step takes 10 ms and the application is invoked 250M times a month (~100 application invocations/second). Since the workflow takes 40 ms total, this works out to 10M execution seconds per month. Assuming a 512MB executor is used for both DBOS Cloud and Lambda, here’s how the cost compares:
### DBOS Cloud Cost
We’ll assume that in DBOS, the application is implemented as four operations in a [DBOS Transact](https://github.com/dbos-inc/dbos-transact) reliable workflow. Stateful, reliable workflow execution is built into DBOS, so there is no need for a separate orchestrator like AWS Step Functions. The 10M execution seconds per month falls within the $40 per-month DBOS Cloud Pro pricing tier, so the total cost is $40 per month.
### AWS Lambda + AWS Step Functions Cost
In AWS Lambda, this application would likely be implemented as four functions orchestrated by an AWS Step Functions workflow. AWS Lambda [charges](https://aws.amazon.com/lambda/pricing/) $0.20 per 1M function invocations plus $8.33 per 1M execution seconds (assuming a 512MB executor). Additionally, AWS Step Functions [charges](https://aws.amazon.com/step-functions/pricing/) (using Express Workflows, the cheapest option) $1.00 per 1M workflow invocations plus $8.33 per 1M operation-seconds of execution. Thus the total cost for Lambda is $200 for the 1B function invocations (four per workflow) plus $83.33 for 10M execution seconds. The total cost for Step Functions is $250 for 250M workflow invocations plus $83.33 for 10M operation-seconds. The grand total is $616.66. As we said earlier in this post, that is over 15 times more expensive than DBOS Cloud. Here's a table to summarize our cost comparison:
## Try it out!
To get started with DBOS, follow our [quickstart](https://docs.dbos.dev/getting-started/quickstart) to download the open-source [DBOS Transact](https://github.com/dbos-inc/dbos-transact) framework and start running code locally.
If you have any questions about the article or about DBOS, please ask in the comments! | kraftp |
1,886,329 | Why I Recommend SQLynx as the Best SQL IDE | I used to be a loyal Navicat、DataGrip user, but after deeply using SQLynx for a while, I can never go... | 0 | 2024-06-13T00:40:30 | https://dev.to/concerate/why-i-recommend-sqlynx-as-the-best-sql-ide-316l | I used to be a loyal Navicat、DataGrip user, but after deeply using SQLynx for a while, I can never go back. I feel like shouting: This is the SQL IDE/Editor that should be used in 2024.
If I were to sum up SQLynx in one sentence, it would be: "What you don't have, I have; what you have, I excel in."
For instance, in basic data exporting, most big data SQL Editor on the market are either extremely slow or prone to crashing when handling large volumes of data. SQLynx, on the other hand, exports 13 million records in just 74 seconds. If you frequently deal with exporting large datasets, you'll understand just how remarkable this speed is.
Another example is its interface and interaction design. Instead of using toolbars or buttons like most tools, SQLynx places almost all operations within the right-click menu. Honestly, I wasn't used to it at first, but after less than a week, I realized this is the best way to interact with the tool! In Navicat, viewing table structure and table data requires many clicks, but with SQLynx, it only takes two steps, greatly improving work efficiency. There are many similar features that enhance productivity.
Regarding the learning curve, Navicat or DataGrip is actually quite easy to get started with, but SQLynx takes it to another level, making it accessible even for beginners. Its graphical table creation, one-click SQL generation, test data generation, one-click data migration, and schema comparison can all be accomplished with just a few mouse clicks. It’s not an exaggeration to say that even if you don't know a single line of SQL, you can complete basic database query operations within 15 minutes. Additionally, thanks to the aforementioned right-click design, SQLynx's interface is also more intuitive.
| concerate | |
1,886,328 | Fraud Detection and Prevention in Finance | Fraud detection and prevention is crucial for safeguarding financial assets and maintaining customer... | 0 | 2024-06-13T00:37:08 | https://dev.to/miniailive/fraud-detection-and-prevention-in-finance-5fmd | webdev, androiddev, machinelearning, ai | Fraud detection and prevention is crucial for safeguarding financial assets and maintaining customer trust. Businesses face increasing threats from cybercriminals who use sophisticated methods to commit fraud. Implementing robust fraud detection systems helps identify suspicious activities early. Techniques like machine learning, data analytics, and real-time monitoring play a significant role in these systems.
Effective fraud prevention measures not only protect assets but also enhance the overall security framework of an organization. Companies must continuously update their strategies to keep pace with evolving fraud tactics. Investing in advanced fraud detection tools and employee training is essential for a comprehensive defense.
Full article:
https://miniai.live/fraud-detection-and-prevention-safeguard-your-finances-now/ | miniailive |
1,886,327 | Abstraction | Abstraction is simplifying concepts to ease our work. Instead of code being specific to hardware, it... | 0 | 2024-06-13T00:34:41 | https://dev.to/mpreams/abstraction-1hdb | cschallenge | Abstraction is simplifying concepts to ease our work. Instead of code being specific to hardware, it depends on the abstract concept of the solution. | mpreams |
1,886,325 | Building a Real-Time Chat Application with Firebase | Introduction In today's fast-paced world, real-time communication has become a crucial... | 0 | 2024-06-13T00:32:29 | https://dev.to/kartikmehta8/building-a-real-time-chat-application-with-firebase-23k9 | webdev, javascript, beginners, programming | ## Introduction
In today's fast-paced world, real-time communication has become a crucial aspect of our daily lives. Building a real-time chat application has become essential for businesses, organizations, and even individuals. Firebase, a popular Backend as a Service (BaaS) platform, offers an easy and efficient solution for creating real-time chat applications. In this article, we will explore the advantages, disadvantages, and features of using Firebase to build a real-time chat application.
## Advantages
The use of Firebase in developing a real-time chat application offers several benefits such as easy integration, real-time updates, and scalability. Firebase allows for a quick and seamless integration of all the necessary features, such as user authentication, push notifications, and offline data storage. It also provides real-time updates, ensuring that the chat application is kept up to date with the latest messages. Additionally, Firebase's cloud-based infrastructure allows for effortless scalability, ensuring that the application can handle a large volume of users without any hiccups.
## Disadvantages
One of the major disadvantages of using Firebase for a real-time chat application is its dependency on a stable internet connection. Without a stable internet connection, the application's real-time updates and data storage may not function correctly. Another potential issue is the lack of control over the database, as Firebase handles all aspects of the database, making it difficult to troubleshoot any issues that may arise.
## Features
Firebase offers several important features that make it an ideal choice for building a real-time chat application. Some of these include real-time data synchronization, user authentication, and offline data storage. It also provides a secure and reliable infrastructure to ensure the smooth functioning of the chat application. Firebase also offers a simple and easy-to-use SDK (Software Development Kit) that enables developers to add and customize features as per their requirements.
### Key Features Detailed
1. **Real-time Data Synchronization:**
Firebase's real-time database allows users to see chat updates instantly without needing to refresh the application.
2. **User Authentication:**
Firebase provides various authentication options including email and password, phone numbers, and popular third-party providers like Google, Facebook, and Twitter.
3. **Offline Data Storage:**
Firebase apps remain responsive even in offline mode by caching data locally. Once the connection is restored, it syncs the data with the cloud.
## Conclusion
In conclusion, Firebase provides a convenient and efficient way to build real-time chat applications. With its easy integration, real-time updates, and scalability, it is a popular choice among developers. However, it is crucial to consider the disadvantages, such as its dependency on a stable internet connection and limited control over the database, before choosing Firebase for building a real-time chat application. Overall, with its impressive features and benefits, Firebase is undoubtedly a great option for creating a real-time chat application.
| kartikmehta8 |
1,886,324 | APIs | Application Programming Interfaces (API) are how we can write programs that get and post information... | 0 | 2024-06-13T00:26:27 | https://dev.to/mpreams/apis-2bnk | cschallenge | Application Programming Interfaces (API) are how we can write programs that get and post information with another live source of data. It's like a menu at your favorite restaurants. | mpreams |
1,885,012 | Elixir Process, what is? how work? What is linked & monitored process | One of some difficult to understand from other languages go to Elixir is process (a lightweight/green... | 0 | 2024-06-13T00:22:38 | https://dev.to/manhvanvu/elixir-process-what-is-how-work-bgj | One of some difficult to understand from other languages go to Elixir is process (a lightweight/green thread, not OS process) and people usually ignore it to use libraries.
Actually, Elixir process is very powerful thing, If go to work with large scale system we need to do with process a lot.
I have long time work with Erlang (also Golang) and process is one of most interesting thing for me.
From my view, process in Elixir has 3 important things to care.
1. Process is isolated code (like an island in ocean) & send/receive message is a way to communicate with outside world. If process is die, it doesn't affect to other processes (except one case is linked process).
2. Process can be monitor to know how process is exited (:normal, :error,..).
3. Process can be linked (group together) and all processes linked with failed process will be die (except only case is process turn trap_exit to true).
From 3 things above we can made a lot of things with process like: build a custom supervisor/worker model, simple make a pool processes to share workload, make a chain data processing,...
Now we go through one by one for understand Elixir process concept.
**Isolated code in process**
Work in Elixir much more easy if we understand how it works. From sharing variables (mutable variables) a lit of bit feel hard to bring algorithms (also real loop/while for Elixir). Just imagine you live alone on an island in the ocean and just to one way to communicate with outside by put message to a bottle then ocean will care anything else.
(Actually, we can share state by `:ets`, `:persistent_term`or another database like :mnesia).
To start new a process we use `spawn`, `spawn_link` or `spawn_monitor` function. An other way to start a process is use Supervisor I will talk about this in other post.
Create a process:
```Elixir
spawn(fn ->
sum = Enum.reduce(1..100, 0, fn n, acc -> acc + n end)
IO.puts "sum: #{inspect sum}"
end)
```
After spawn (created) process will have a `PID` to identify for communicate or control. We can `register` a name (an atom) for process.
Register a name for process:
```Elixir
# Register name for current process
Process.register(self(), :my_name)
# Register name for other process.
Process.register(pid, :my_friend)
```
When you want to send a message you put message with address to bottle then go to beach and throw the bottle to the ocean. With a little bit of time your friend you will receive a message.
And when you want to get a message from other islands you go to the beach and see if has any bottle in the beach, check then get only message you needed (by use pattern matching), other messages stills on the beach.
For action like server/client, you send a message and stay at the beach with time (or forever) to get a feedback (send from island that received your message).
To send in code we use `send/2` function:
```Elixir
send(pid, {:get, :user_info, self()})
```
To receive message (already in mailbox or wait new one) we use `receive do` syntax just like `case do`:
```Elixir
receive do
{:user_info, data} ->
IO.puts "user data: #{inspect data}"
other ->
IO.puts "other data: #{inspect other}"
end
```
You can put `receive do` to a function to go to loop again if you want to make process like a server.
In case you want to wait with time, you can use `after N` with `N` is:
0 - Just check existed messages in mailbox, doesn't wait.
> 0 - Wait in N miliseconds.
`:infinity` - Wait forever.
Example:
```Elixir
receive do
{:user_info, data} ->
IO.puts "user data: #{inspect data}"
after 3_000 ->
IO.puts "timeout, nothing for me :("
end
```
In case message doesn't match any pattern in `receive do` it still stay in mailbox of process. You can get it in the future but need sure do not push a lot un matched message to process because it can make a OMM.
**link processes**
This is very powerful feature of Elixir. We can control a group of processes for do group tasks, chain of tasks and if any of process failed, other processes will die. We don't need take time for clean up that.
Example:
Process A --linked--> B --linked--> C
```Elixir
IO.puts "I'm A"
fun = fn ->
receive do
:shutdown ->
IO.puts "exited"
{:ping, from} ->
IO.puts "got a ping from #{inspect from}"
send(from, :pong)
message ->
IO.puts "Got a message: #{inspect message}"
end
end
# spawn and link process B
spawn_link(fn ->
IO.puts "I'm B"
spawn_link(fn ->
IO.puts "I'm C"
fun.()
end)
fun.()
end)
```
From this code we link processes in chain task. If any process failed all other processes will die also.
We also make can group like:
Process leader --linked--> worker1, worker2, ..., workerN
And any process is failed all other processes will die follow.
**trap_exit**
In case we don't want a process go to die follow failed process we can turn `trap_exit` on (set flag to true) and process will receive a failed message instead die follow other processes.
```Elixir
Process.flag(:trap_exit, true)
```
Your process will receive a message like below when linked to your process failed.
```Elixir
{:EXIT, #PID<0.192.0>, {%RuntimeError{message: "#PID<0.192.0>, raise a RuntimeError :D"}, []}}
```
**monitor process**
In other case, we just want to now why other process is crashed we can use `monitor` process.
Have some function for monitor process: `spawn_monitor`, `Process.monitor` for make a monitor to other process.
For remove monitor we can use `Process.demonitor`.
If monitored process is failed a process make monitor to that process will receive a message like:
```Elixir
{:DOWN, #Reference<...>, :process, #PID<...>, reason}
```
From link/monitor process we can make a lot of things for our system and we can sleep well! We can make a our specific supervisor, our custom pool workers, chain task, fast fail task,...
In this time I just a explain in basic, I will explain more detail in the future.
I have LiveBook for similar this you can check a and see content + source demo on [our Github repo](https://github.com/ohhi-vn/sharing_elixir_sg_elixir_dec_6)
I will go to details in other posts.
Thank for reading! | manhvanvu | |
1,886,311 | Let’s Build Small AI Buzz, Offer ‘Claim Processing’ to Mid/Big Companies | Discover How AI Can Transform Businesses, Every Details Spelled Out. Full Article Artificial... | 0 | 2024-06-13T00:18:25 | https://dev.to/exploredataaiml/lets-build-small-ai-buzz-offer-claim-processing-to-midbig-companies-3dkn | llm, rag, machinelearning, genai | Discover How AI Can Transform Businesses, Every Details Spelled Out.
[Full Article] (https://medium.com/@learn-simplified/lets-build-small-ai-buzz-offer-claim-processing-to-mid-big-companies-d589f008d724)
Artificial Intelligence (AI) is rapidly reshaping business landscapes, promising unprecedented efficiency and accuracy across industries. In this article, we delve into how Aniket Insurance Inc. (Imaginary) leverages AI to revolutionize its claim processing operations, offering insights into the transformative power of AI in modern business environments.
➡️ What’s This Article About?
* The article explores how Aniket Insurance Inc. uses AI to transform its claim processing.
* It details the three main workflows: User claim submission, Admin + AI claim processing, and Executive + AI claim analysis.
➡️ Why Read This Article
* Readers can see practical ways AI boosts efficiency in business, using Aniket Insurance as an example.
* AI speeds up routine tasks, like data entry, freeing up humans for more strategic work.
It shows how AI-driven data analysis can lead to smarter business decisions.
➡️Let’s Design:
Aniket Insurance Inc. has implemented AI architecture that encompasses three pivotal workflows: User Claim Submission Flow, Admin + AI Claim Processing Flow, and Executive + AI Claim Analysis Flow. Powered by AI models and integrated with store, this architecture ensures seamless automation and optimization of the entire claim processing lifecycle. By leveraging AI technologies like machine learning models and data visualization tools, Aniket Insurance how business can enhance operational efficiency, and strategic decision-making capabilities.
➡️Closing Thoughts:
Looking ahead, the prospects of AI adoption across various industries are incredibly exciting. Imagine manufacturing plants where AI optimizes production lines, predicts maintenance needs, and ensures quality control. Envision healthcare facilities where AI assists in diagnosis, treatment planning, and drug discovery. Picture retail operations where AI personalizes product recommendations, streamlines inventory management, and enhances customer service. The possibilities are endless, as AI’s capabilities in pattern recognition, predictive modeling, and automation can be leveraged to tackle complex challenges and uncover valuable insights in virtually any domain. | exploredataaiml |
1,886,307 | Simple way to obtain largest Number in an array or slice in golang | 🚀 Step-by-Step Guide to Find the Largest Number in an Array in Go Finding the largest... | 0 | 2024-06-13T00:09:08 | https://dev.to/toluwasethomas/simple-way-to-obtain-largest-number-in-an-array-or-slice-in-golang-2o06 | webdev, beginners, go, arrays | # 🚀 Step-by-Step Guide to Find the Largest Number in an Array in Go
Finding the largest number in an array is a common task in programming. Let's walk through a simple yet effective approach to accomplish this in Go.
## 📝 Steps to Follow
### 1️⃣ Loop through Each Value
Iterate through each element of the array or slice.
### 2️⃣ Declare the Initial Largest Value
Initialize a variable `largest` with the first element of the array:
largest := array[0]
### 3️⃣ Compare the Current Largest Value with Other Numbers
Compare the current `largest` value with each element in the array.
### 4️⃣ Update the Largest Value
Whenever you find a number greater than the current `largest` value, update `largest` to this new number.
### 5️⃣ Return the Largest Value
After completing the loop, return the `largest` number.
```
func findLargestNumber(nums []int) int {
if len(nums) == 0 {
return 0 // handle empty slice case
}
largest := nums[0] // Step 2
for i := 1; i < len(nums); i++ { // Step 1
if nums[i] > largest { // Step 3
largest = nums[i] // Step 4
}
}
return largest // Step 5
}
```
Testing the function
```
func TestFindLargestNumber(t *testing.T) {
tests := []struct {
name string
numbers []int
expected int
}{
{
name: "Mixed positive numbers",
numbers: []int{45, 22, 68, 90, 12},
expected: 90,
},
{
name: "All negative numbers",
numbers: []int{-5, -23, -1, -55},
expected: -1,
},
{
name: "All zeros",
numbers: []int{0, 0, 0, 0, 0},
expected: 0,
},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
got := findLargestNumber(tt.numbers)
if got != tt.expected {
t.Errorf("findLargestNumber(%v) = %v, want %v", tt.numbers, got, tt.expected)
}
})
}
}
```
Main Function
```
func main() {
arr := []int{45, 22, 68, 90, 12}
fmt.Println(findLargestNumber(arr)) // Output: 90
}
```
Thanks for reading.
Kindly like and share other methods you know of in the comments below. | toluwasethomas |
1,886,306 | CODER CYBER SERVICES // RECOVER STOLEN CRYPTOCURRENCY | In cyberspace, where promises gleam like diamonds but often lead to deceptive traps, one can easily... | 0 | 2024-06-12T23:56:36 | https://dev.to/christine_kradolfer_891e5/coder-cyber-services-recover-stolen-cryptocurrency-5p5 | In cyberspace, where promises gleam like diamonds but often lead to deceptive traps, one can easily lose themselves. I found myself ensnared in this digital maze when a seemingly promising investment opportunity turned into a nightmare. It all began innocuously enough with an invitation to join a Telegram group promising untold riches through cryptocurrency trading. Intrigued, I dipped my toes into the world of digital assets, unaware of the peril lurking beneath the surface. As I delved deeper, enticed by the allure of quick profits, I stumbled upon a trading platform promising unparalleled returns. Entranced by the prospect of financial freedom, I invested a substantial sum, hoping to secure a better future. Yet, what started as a journey toward prosperity soon spiraled into a harrowing ordeal. The initial euphoria of successful trades soon gave way to apprehension as the platform's promises began to unravel. Withdrawals, once smooth and effortless, became increasingly difficult, with excuses and delays becoming the norm. Panic set in as I realized the gravity of my situation – I had fallen victim to a sophisticated scam, orchestrated by individuals adept at exploiting the vulnerabilities of unsuspecting investors. Desperate for a lifeline amidst the chaos, I turned to Coder Cyber Services, recovery experts. From the moment I reached out to them, their unwavering commitment to my cause was palpable. They listened attentively to my story, offering solace and reassurance in equal measure. Their empathy and unparalleled expertise in digital asset recovery instilled in me a renewed sense of hope. With meticulous precision, Coder Cyber Services embarked on the arduous journey of reclaiming what was rightfully mine. Their team of experts navigated the complexities of blockchain technology and digital transactions with finesse, leaving no stone unturned in their quest for justice. Despite the formidable challenges posed by the elusive nature of cryptocurrency scams, they remained undeterred, driven by a steadfast determination to right the wrongs inflicted upon me. As the days turned into weeks, and the weeks into months, Coder Cyber Services kept me informed every step of the way. Their transparent communication and regular updates reassured me during the tumultuous recovery process. Their unwavering dedication to my case was nothing short of commendable, serving as a beacon of hope in an otherwise bleak landscape. Finally, after what seemed like an eternity of waiting and uncertainty, the moment of triumph arrived – Coder Cyber Services succeeded in reclaiming my lost assets in their entirety. The joy and relief I felt were indescribable, akin to emerging from the depths of despair into the warm embrace of sunlight. Their victory was not just a testament to their expertise but also a testament to the power of perseverance and resilience in the face of adversity. Coder Cyber Services serves as a testament to the indomitable human spirit and the unwavering pursuit of justice. Their unwavering commitment, empathetic approach, and exceptional expertise make them the ultimate ally in the battle against digital fraud. If you find yourself entangled in the web of deception, do not despair – Seek refuge from Coder Cyber Services via the below data information.
Homepage:https://codercyberservices.info
E-Mail:codercyberservices@tech-center.com
Email: enquiry@codercyberservices.info
Best wishes | christine_kradolfer_891e5 | |
1,886,305 | Anyone who likes games | I have a fun game for everyone to play eaglercraft.com its unblocked and free | 0 | 2024-06-12T23:55:18 | https://dev.to/scarlett_exe/anyone-who-likes-games-25pc | I have a fun game for everyone to play eaglercraft.com its unblocked and free | scarlett_exe | |
1,886,304 | Day 969 : keep | liner notes: Professional : So...no code was written today. haha I was in meetings, responding to... | 0 | 2024-06-12T23:55:04 | https://dev.to/dwane/day-696-keep-5c5h | hiphop, code, coding, lifelongdev | _liner notes_:
- Professional : So...no code was written today. haha I was in meetings, responding to community questions, booking a hotel room and filling out a visa. But got it all done.
- Personal : Went through some tracks for the radio show. Played around with the settings of the highlight video creator and I think I got to a good place with speed, quality and file size. Definitely went down multiple rabbit holes.
Going to go through more tracks for the radio show. I want to refactor the code for my highlight video creator to clean it up. I'll keep the settings I have now and see how they work in an actual application. I also want to work on a logo for a side project and subscribed to a drawing app that I thought would allow me to be able to sync files between all my devices. I purchased a yearly subscription to only find out that I misread the info and the files stay on the device and are not synced. Good thing there was a 7 day trial before the charge, so I cancelled. It was then that I realized that I had a drawing program that I was already paying for that syncs across devices. So yeah, hoping to get the logo done. I have a sketch, but want to clean it up. Got a late start to my evening. Going to get to work.
Have a great night!
peace piece
Dwane / conshus
https://dwane.io / https://HIPHOPandCODE.com
{% youtube MGpaitAgVgI %} | dwane |
1,886,302 | How to Prepare for Driving School in Vienna | Preparing for driving school is a crucial step toward becoming a confident and responsible driver.... | 0 | 2024-06-12T23:44:00 | https://dev.to/novadriving_school_eaa910/how-to-prepare-for-driving-school-in-vienna-3fg4 | Preparing for driving school is a crucial step toward becoming a confident and responsible driver. Whether you're gearing up for your first driving lesson or refreshing your skills, adequate preparation is key to success. In this guide, we'll delve into the essential steps to prepare for [driving school in Vienna](https://www.novadrivingschoolva.com/driving-school-vienna-va/
) and Fairfax. From understanding the requirements to mastering driving techniques, let's ensure you're fully equipped to embark on this exciting journey.
Understanding the Requirements: Before diving into driving school, it's essential to understand the requirements set forth by the Vienna and Fairfax authorities. Typically, aspiring drivers must meet certain criteria to enroll in driving school. These may include age restrictions, residency requirements, and prerequisites for learner's permits or driver's licenses. Familiarize yourself with these prerequisites to ensure you're eligible to begin your driving education journey.
Subheading 1: Obtaining Necessary Documentation To kickstart your journey toward obtaining a driver's license, you'll need to gather necessary documentation. This often includes proof of identity, residency, and, in some cases, parental consent for minors. Additionally, ensure you have any required medical certifications or vision tests completed as per local regulations. By organizing these documents beforehand, you'll streamline the enrollment process and avoid unnecessary delays.
Subheading 2: Choosing the Right Driving School Selecting the right driving school is paramount to your success as a driver. In Vienna and Fairfax, numerous driving schools offer varying programs and teaching styles. Research different schools in your area, read reviews, and consider factors such as instructor experience, lesson schedules, and pricing. Opt for a reputable school that aligns with your learning preferences and budget.
Subheading 3: Familiarizing Yourself with Traffic Laws A solid understanding of traffic laws lays the foundation for safe and legal driving. Take the time to familiarize yourself with Vienna and Fairfax's traffic regulations, including speed limits, right-of-way rules, and signage meanings. You can access comprehensive resources online, including official government websites and driving manuals. Additionally, consider taking practice tests to assess your knowledge and identify areas for improvement.
Subheading 4: Practicing Basic Driving Skills While formal driving lessons are invaluable, practicing basic driving skills beforehand can boost your confidence behind the wheel. Find a safe and empty parking lot to practice fundamental maneuvers such as steering, braking, and parking. Familiarize yourself with operating the vehicle's controls, including turn signals, headlights, and windshield wipers. By honing these skills early on, you'll feel more comfortable during your driving lessons.
Subheading 5: Understanding Vehicle Mechanics A basic understanding of vehicle mechanics can enhance your driving experience and troubleshoot potential issues on the road. Learn how to perform routine maintenance tasks such as checking tire pressure, fluid levels, and brake functionality. Familiarize yourself with dashboard indicators and their meanings to promptly address any warning signs. Additionally, know how to handle common roadside emergencies such as flat tires or dead batteries.
Subheading 6: Cultivating a Defensive Driving Mindset Defensive driving is a cornerstone of safe and responsible motoring. Embrace a defensive driving mindset by staying alert, anticipating potential hazards, and maintaining a safe following distance. Practice scanning your surroundings, including checking blind spots and mirrors frequently. Stay vigilant for erratic drivers, pedestrians, and adverse weather conditions. By prioritizing safety and awareness, you'll mitigate risks and navigate roads with confidence.
Subheading 7: Setting Realistic Goals As you prepare for driving school, set realistic goals to gauge your progress and track your achievements. Establish milestones such as mastering parallel parking, navigating busy intersections, or driving in diverse weather conditions. Break down larger goals into manageable tasks and celebrate each milestone along the way. By setting clear objectives, you'll stay motivated and focused throughout your driving education journey.
Conclusion: Preparing for Driving School in Fairfax and Fairfax requires dedication, preparation, and a commitment to safety. By understanding the requirements, choosing the right school, and honing your driving skills, you'll embark on this journey with confidence and competence. Remember to prioritize safety, stay patient with yourself, and embrace the learning process wholeheartedly. With the right mindset and preparation, you'll soon be on the road to becoming a skilled and responsible driver.
Driving School in Vienna | novadriving_school_eaa910 | |
1,407,116 | Why batch jobs are so difficult? | The detail data produced in the business system usually needs to be processed and calculated to our... | 0 | 2023-03-19T23:54:33 | https://dev.to/jbx1279/why-batch-jobs-are-so-difficult-155e | database, bigdata, sql, programming | The detail data produced in the business system usually needs to be processed and calculated to our desired result according to a certain logic so as to support the business activities of enterprise. In general, such data processing will involves many tasks, and it needs to calculate in batches. In the bank and insurance industries, this process is often referred to as “batch job”, and batch jobs are often needed in other industries like oil and power.
Most business statistics require taking a certain day as termination day, and in order not to affect the normal business of the production system, batch jobs are generally executed at night, only then can the new detail data produced in production system that day be exported and transferred to a specialized database or data warehouse to perform operations of the batch jobs. The next morning, the result of batch job can be provided to business staff.
Unlike on-line query, batch job is an off-line task that is automatically carried out on a regular basis, and hence the situation that multiple users access one task at the same time will never occur, so there is no concurrency problem and no need to return the result in real time. However, the batch job must be accomplished within a specified time period. For example, the specified time period for batch job of a bank is from 8:00 pm the first day to 7:00 am the next day, if the batch job is not accomplished by 7:00 am, it will cause serious consequence that the business staff cannot work normally.
The data volume involved in a batch job is very large, and it is likely to use all historical data. Moreover, since the computing logic is complex and involves many computing steps, the time of batch jobs is often measured in hours. It is very common to take two or three hours for one batch job, and it is not surprising to take ten hours. As business grows, the data volume increases. The rapid increase of computational load on database that handles batch job will lead to a situation where the batch job cannot be accomplished after the whole night, and this will seriously affect the business, which is unacceptable.
# Problem analysis
To solve the prolonged time of batch job, we must carefully analyze the problem existed in the existing system architecture.
The relatively typical architecture of batch job system is roughly as follows:
As can be seen from the figure that the data needs to be exported from the production database and imported into the database handling batch jobs. The latter database is usually an RDB, you need to write stored procedure code to perform calculation of the batch jobs. The result of batch jobs will not be used directly in general, but will be exported from RDB to other systems in the form of intermediate files or imported into the database of other systems. This is a typical architecture, and the production database in the figure may be a centralized data warehouse or Hadoop, etc. Generally, the two databases in the figure are not the same database, and the data transferred between them is often in the form of file, which is conducive to reducing the degree of coupling. After the batch jobs are accomplished, the result is to be used in multiple applications, and transferred also in the form of file.
The first reason for slow batch jobs is that the data import/export speed of RDB for batch jobs is too slow. Due to closed storage and computing capacities of RDB, too many constraint verifications and security processing at data import/export are required. When the data volume is large, the data read/write efficiency will be very low, and it will take a very long time. Therefore, for the database that handles batch jobs, both the process of importing file data and the process of exporting calculation result as file will be very slow.
The second reason for slow batch jobs is that the performance of stored procedure is poor. Since the syntax system of SQL is too old, and there are many limitations, resulting in a failure in the implementation of many efficient algorithms, the computing performance of SQL statements in stored procedure is not unsatisfactory. Moreover, when the business logic is relatively complex, it is difficult to achieve within one SQL statement, and instead divide into multiple steps and use a dozen or even tens of SQL statements to implement. The intermediate result of each SQL statement needs to be stored as a temporary table for use in the SQL statements of subsequent steps. When the temporary table stores a large amount of data, the data must be stored, which will cause a large amount of data to be written. However, the performance of writing data is much worse than that of reading data, it will seriously slow down the entire stored procedure.
For more complex calculations, it is even difficult to implement directly in SQL statements. Instead, it needs to use a database cursor to traverse and fetch the data, and perform loop computing. However, the performance of database cursor traversal computing is much worse than that of SQL statements, and this method generally does not directly support the multi-thread parallel computing, and is difficult to use the computing capacity of multiple CPU cores, as a result, it will make computing performance become worse.
Then, how about using a distributed database (increase the number of nodes) to replace traditional RDB to speed up batch jobs?
No, we can't. The main reason is that the batch job logic is quite complex, and it often needs thousands or even tens of thousands of lines of code to achieve even using the stored procedures of traditional database, yet the computing capacity of stored procedures of distributed database is still relatively weak, making it difficult to implement such complex batch operations.
In addition, the distributed database also faces the problem of storing the intermediate result when a complex computing task has to be divided into multiple steps. Since the data may be stored on different nodes, it will result in heavy cross-network reads/writes whether storing intermediate result in previous steps or re-reading in subsequent steps, leading to uncontrollable performance.
In this case, using a distributed database to speed up query via data redundancy does not work as well. The reason is that although multiple copies of redundant data can be prepared in advance before querying, the intermediate results of batch job are generated temporarily, and it needs to temporarily generate multiple copies of data if the data are redundant, which will make overall performance become slower.
Therefore, the real-world batch job is usually executed within a large single database. When the computational intensity is too high, an all-in-one machine like ExaData will be used (ExaData is a multiple-database platform, and can be regarded as a super large single database as it is specially optimized in Oracle). Although this method is very slow, there is no better choice for the time being, and only such large databases have enough computing capacity for batch jobs.
# Using SPL to perform batch jobs
SPL, an open-source professional computing engine, offers the computing capacity that does not depend on database, and directly uses the file system to compute, and can solve the problem of extremely slow data import and export of RDB. Moreover, SPL achieves more optimized algorithms, and far surpasses stored procedure in performance, and has the ability to significantly improve computing efficiency of one machine, which is very suitable for batch jobs.
The new architecture that uses SPL to implement batch jobs is shown as below:
In this new architecture, SPL solves two bottlenecks that cause slow batch jobs.
Let’s start with the first bottleneck, i.e., data import and export. SPL can perform calculation directly based on file exported from production database, and there is no need to import data into an RDB. Having finished batch jobs, SPL can directly store final result as general format such as text file and transfer it to other applications, avoiding the data export from original database that handles batch jobs. In this way, slow RDB read/write is omitted.
Now let's look at the second bottleneck, that is, the computing process. SPL provides better algorithms (many of which are pioneered in the industry), and the computing performance far outperforms that of stored procedure and SQL statement. SPL’s high-performance algorithms include:
These high-performance algorithms can be used for common calculations in batch job such as JOIN calculation, traversing, grouping and aggregating, which can effectively improve the computational speed. For example, the batch jobs often involve traversing the entire history table, and in some cases, a history table needs to be traversed many times so as to accomplish the calculations of multiple business logics. Generally, the data amount of history table is very large and each traversal will consume a lot of time. To solve this problem, we can use SPL’s **multi-purpose traversal** mechanism. This mechanism can accomplish multiple computations during one round of traverse on a large table, and can save a lot of time.
SPL’s **multi-cursor** can achieve parallel reading and computing of data. Even for complex batch job logic, the use of multiple CPU cores can implement multi-thread parallel computing. On the contrary, it is difficult for database cursor to process in parallel. Thus, the computing speed of SPL can often be several times faster than that of stored procedure.
The **delayed cursor** mechanism of SPL has the ability to define multiple computation steps on one cursor, and then let the data stream perform these steps in sequence to achieve **chain calculation**. This mechanism can effectively reduce the number of times of storing intermediate result. In situations where data must be stored, SPL can store intermediate result as its built-in high-performance format for use in the next step. SPL’s high-performance storage is based on file, and adopts many technologies such as **ordered and compression storage, free columnar storage, double increment segmentation, self-owned compression code**. As a result, the disk space occupation is reduced, and the read and write speed is much faster than database.
# Application effect
In this new architecture, SPL breaks RDB’s two bottlenecks for batch jobs, and obtains very good effect in practice. Let's take three cases to illustrate.
Case 1: Bank L adopts traditional architecture for its batch jobs, and takes RDB as the database handing batch jobs, and uses stored procedure to program to achieve batch job logic. It takes 2 hours to carry out the stored procedure of the batch job of loan agreements, yet this is merely a preparation job for many other batch jobs. Taking so long time seriously affects all batch jobs.
When using SPL, due to its high-performance algorithms and storage mechanisms such as the **high-performance columnar storage, file cursor, multi-thread parallel processing, small result in-memory grouping, and multi-purpose cursor**, the computing time is reduced from 2 hours to 10 minutes, **the performance is improved by 12 times**.
Moreover, SPL code is more concise. For the original stored procedure, there are more than 3300 lines of code, yet it only needs 500 cells of statements in SPL, **reducing the code amount by more than 6 times** and greatly improving development efficiency.
Visit: http://c.raqsoft.com/article/1644215913288
Case 2: In the car insurance business of insurance company P, it needs to associate historical policies of previous years with new policies, which is called the historical policies association batch job. When RDB is used for this batch job, and using the stored procedure to associate historical policies with 10-day new policies, it will take 47 minutes, and take 112 minutes to associate 30-day new policies; if the time span increases, the computation time will be unbearably long, and it will basically become an impossible task.
When SPL is used for the calculation task, after exploiting SPL’s technologies such as **high-performance file storage, file cursor, ordered merging & segmented data-fetching, in-memory association and multi-purpose traversal**, it only takes 13 minutes to associate 10-day new policies, and takes 17 minutes to associate 30-day new policies, the speed is **increased by nearly 7 times**. Moreover, the computation time of new algorithms slightly increases as new policies grow, and does not increase in direct proportion to the number of days of new policies just like stored procedure.
Viewing from the total code volume, there are 2000 lines of code in original stored procedure, and are still more than 1800 lines after removing the comments. In contrast, SPL codes are less than 500 cells, which is **less than 1/3 of original code volume**.
For details, visit: http://c.raqsoft.com/article/1644827119694
Case 3: For the detail data of granted loans of Bank T through Internet, it requires running a batch job on a daily basis to count and aggregate all historical data as of a specified date. If this batch job is implemented in SQL statements of RDB, the total running time is 7.8 hours, which is too long, and even affects other batch jobs, and hence it is necessary to optimize.
When SPL is used, and after exploiting SPL’s technologies like **the high-performance file, file cursor, ordered grouping, ordered association, delayed cursor and binary search**, the running time can be reduced from 7.8 hours to 180 seconds in the case of single thread, and to 137 seconds in 2-thread, the speed is **increased by 204 times**.
Origin: https://blog.scudata.com/why-batch-jobs-are-so-difficult/
SPL Source code: https://github.com/SPLWare/esProc | jbx1279 |
1,886,301 | Recursion | Recursion can be referred to as a function in programming that calls itself to solve some part of the... | 0 | 2024-06-12T23:40:51 | https://dev.to/ismailajat14162/recursion-4jnh | devchallenge, cschallenge, computerscience, beginners | Recursion can be referred to as a function in programming that calls itself to solve some part of the problem or task in a repeated manner until its reach optimal solution. Example sorting random numbers in descending order by comprising each number at a time.
| ismailajat14162 |
1,886,299 | [JavaScript] Generate Unique Code | Script que genera código único. El script se basa en las siguientes condiciones: Debe tener una... | 0 | 2024-06-12T23:30:06 | https://dev.to/jkdevarg/javascript-generate-unique-code-2jlj | javascript, beginners, programming, github | Script que genera código único.
El script se basa en las siguientes condiciones:
- Debe tener una longitud de 6 caracteres
- Debe empezar con las siguientes letras "M", "B", "L"
- Debe ser todo en mayuscula
- No debe contener el número 1
- No se pueden repetir
- Se deben generar 10,000 códigs en 20 archivos de texto
Ejemplo de salida:
```
B3HFHF
L8HMBA
BVQYPM
BG8L4S
B524DA
```
Repositorio: [https://github.com/JkDevArg/generate_unique_codes](https://github.com/JkDevArg/generate_unique_codes) | jkdevarg |
1,886,298 | What is Data Governance? | Introduction Image Credit: Spiceworks In an era where data is considered the new oil,... | 0 | 2024-06-12T23:25:03 | https://dev.to/kellyblaire/what-is-data-governance-54fo | sql, database, datascience, sqlserver | #### Introduction
_Image Credit: [Spiceworks](https://www.spiceworks.com/tech/big-data/articles/what-is-data-governance-definition-importance-and-best-practices/)_
In an era where data is considered the new oil, effective data governance has become essential for organizations to harness the true value of their data assets. Data governance refers to the overall management of the availability, usability, integrity, and security of the data employed in an enterprise. It involves a set of processes, roles, policies, standards, and metrics that ensure the efficient and effective use of information to help an organization achieve its goals.
According to [Spiceworks](https://www.spiceworks.com/tech/big-data/articles/what-is-data-governance-definition-importance-and-best-practices/),
> Data governance is the collection of data management processes and procedures that help an organization manage its internal and external data flows. It aligns people, processes, and technology, to help them understand data to transform it into an enterprise asset.
And [Fortinet](https://www.fortinet.com/resources/cyberglossary/data-governance) has this to say about Data Governance:
> Data governance refers to a system that makes sure only authorized people can interact with specific data—while controlling what they can do, in which situation, and the methods they can use. An effective data governance framework maintains data integrity.
#### Understanding the concept as a 5-year old
I am sure you still do not understand what Data Governance mean.
How about I explain it to you as if you're a 5-year old?
Image credit: Image generated with Meta AI.
Alright, imagine you have a big box of LEGO bricks. You love building different things like houses, cars, and animals. But to make sure your LEGO creations are the best they can be, you need some rules.
1. **Keep them sorted**: You have to keep all the red bricks in one box, all the blue ones in another, and so on. This way, you can find the pieces you need quickly.
2. **Share nicely**: If your friend comes over to play, you both have to agree on which bricks to use so that you can build something together without fighting.
3. **Don't lose pieces**: You have to make sure none of your LEGO bricks get lost under the couch or in the garden because you need all of them to build your creations.
4. **Clean up after playing**: When you're done playing, you have to put all the bricks back in their boxes so that next time, everything is ready for you to play again.
Data governance is like these rules but for grown-ups who work with lots of information. They make sure everything is organized, shared nicely, kept safe, and cleaned up after using it, so everyone can use it to make good decisions and build great things.
I'm sure you understand it now!
#### The Importance of Data Governance
1. **Enhanced Decision Making**: With robust data governance, organizations can ensure the accuracy, completeness, and reliability of their data, leading to better business decisions.
2. **Regulatory Compliance**: Many industries are subject to stringent regulations regarding data privacy and security. Effective data governance helps organizations comply with laws such as GDPR, HIPAA, and CCPA.
3. **Risk Management**: By ensuring data integrity and security, data governance minimizes the risks associated with data breaches and loss, protecting the organization from potential legal and financial repercussions.
4. **Operational Efficiency**: Standardized data processes and policies streamline operations, reducing redundancy and improving efficiency across various departments.
#### Core Components of Data Governance
1. **Data Governance Framework**: This includes the organizational structure, roles, and responsibilities for data management. Key roles typically include data owners, data stewards, and data custodians.
2. **Policies and Standards**: Clear policies and standards guide how data is managed, including data quality standards, data lifecycle management, and data access policies.
3. **Data Quality Management**: Ensuring data is accurate, complete, and consistent is fundamental. This involves data cleansing, data profiling, and ongoing monitoring to maintain high data quality.
4. **Data Security and Privacy**: Safeguarding data from unauthorized access and breaches through encryption, access controls, and anonymization techniques.
5. **Metadata Management**: Effective metadata management provides context and meaning to data, facilitating better understanding and use.
6. **Data Architecture**: Designing and implementing a data architecture that supports the organization’s data strategy and governance policies.
#### Implementing Data Governance
1. **Assessment and Planning**: Begin with a thorough assessment of the current data landscape, identifying gaps and opportunities. Develop a strategic plan that aligns with the organization’s goals and regulatory requirements.
2. **Establish a Governance Framework**: Define the data governance framework, including roles, responsibilities, and decision-making processes. Engage stakeholders across the organization to ensure buy-in and collaboration.
3. **Develop Policies and Standards**: Create comprehensive policies and standards for data management. Ensure these are communicated and enforced across the organization.
4. **Implement Data Quality Management**: Invest in tools and processes for data quality management. Regularly monitor and report on data quality metrics.
5. **Enhance Data Security and Privacy**: Implement robust data security measures and ensure compliance with privacy regulations. Conduct regular audits and assessments to identify and mitigate risks.
6. **Leverage Technology**: Utilize data governance tools and technologies to automate and streamline governance processes. Tools may include data cataloging, data lineage, and data stewardship platforms.
7. **Training and Awareness**: Educate employees on the importance of data governance and their roles in maintaining data integrity. Continuous training and awareness programs are essential.
#### Challenges in Data Governance
1. **Cultural Resistance**: Implementing data governance often requires a cultural shift within the organization. Overcoming resistance to change is a significant challenge.
2. **Complex Data Environments**: Modern organizations deal with vast amounts of data from diverse sources. Managing this complexity requires robust and scalable data governance solutions.
3. **Evolving Regulatory Landscape**: Keeping up with changing data privacy and security regulations can be challenging. Organizations must remain agile to adapt their governance strategies accordingly.
4. **Resource Constraints**: Implementing effective data governance requires significant investment in terms of time, technology, and human resources. Balancing these resources can be difficult.
#### Future of Data Governance
As data continues to grow exponentially, the future of data governance will likely see increased automation and the use of artificial intelligence and machine learning to manage and protect data. Predictive analytics and real-time data governance will become more prevalent, enabling organizations to anticipate and mitigate data issues before they arise.
Moreover, as organizations increasingly recognize data as a strategic asset, data governance will become an integral part of overall corporate governance, with a stronger focus on ethical considerations and data stewardship.
#### Conclusion
Data governance is no longer a luxury but a necessity for modern organizations aiming to leverage their data assets effectively. By implementing a comprehensive data governance framework, organizations can ensure data accuracy, enhance decision-making, comply with regulations, and protect their data from risks. As the data landscape continues to evolve, staying ahead of the curve with robust data governance practices will be crucial for sustained success and competitive advantage. | kellyblaire |
1,886,297 | Vscode Android | if you are looking for visual studio code for android for free, just download VHEditor. its available... | 0 | 2024-06-12T23:23:43 | https://dev.to/collinsomega/vscode-android-45le | if you are looking for visual studio code for android for free, just download VHEditor. its available on playstore. | collinsomega | |
1,886,256 | Certificate at codsoft 🚀 | A post by Alyan Sheikh | 0 | 2024-06-12T22:54:03 | https://dev.to/alyan_sheikh_e1f7c955a630/certificate-at-codsoft-100a |
 | alyan_sheikh_e1f7c955a630 | |
1,886,296 | Api Architecture Styles using GraphQL | Applications need data to function, these are in a database within a server They have a client which... | 0 | 2024-06-12T23:22:06 | https://dev.to/marioflores7/api-architecture-styles-using-graphql-efi | Applications need data to function, these are in a database within a server
They have a client which is the view and a server where the data logic is.
both communicate through an API, the best known is REST
Graphql allow queries to be made on the client side, not on the server side, it is like doing sql on the frontend.
It can be integrated with multiple Backend programming languages such as Javascript (Nodejs), Python, etc.
1.On the client it is a SQL-type query language.
2.The server is an execution environment, it processes the query.
THIS IS EXAMPLE
| marioflores7 | |
1,886,259 | Neural Networks | A neural network is like a lasagna. Each layer (like noodles, cheese, sauce) adds something special.... | 0 | 2024-06-12T23:07:19 | https://dev.to/architjoshi/neural-networks-2862 | cschallenge, neuralnetworks, lasagna, machinelearning | A neural network is like a lasagna. Each layer (like noodles, cheese, sauce) adds something special. The first layer takes in info (ingredients), middle layers mix and change it (cooking), and the last layer gives the final result (a yummy lasagna).
| architjoshi |
1,884,536 | 🎯 Unlock the Magic of Popover Toggletips & Anchor Positioning! | Hey 👋 I hope you're having a great week so far! Here's a quick look at this weeks digest: 🛠️ CSS Gap... | 0 | 2024-06-12T23:00:00 | https://dev.to/adam/unlock-the-magic-of-popover-toggletips-anchor-positioning-2olf | css, ux, portfolio, webdev |
**Hey** 👋 I hope you're having a great week so far! Here's a quick look at this weeks digest:
🛠️ CSS Gap – A game-changer!
🤔 Why is front-end so complicated?
🚀 UX portfolio tips – Make the first cut!
Enjoy & stay inspired 👋 - Adam at Unicorn Club.
---
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The CSS Anchor Positioning specification enables us to position elements relative to an anchor, wherever they are in our web page.
[**The Gap**](https://ishadeed.com/article/the-gap/?utm_source=unicornclub.dev&utm_medium=newsletter&utm_campaign=unicornclub.dev&ref=unicornclub.dev)
An exploration of the pain points that CSS gap solves.
[**Why is front-end development so complicated?**](https://dev.to/shehzadhussain/why-is-front-end-development-so-complicated-3g8o?utm_source=unicornclub.dev&utm_medium=newsletter&utm_campaign=unicornclub.dev&ref=unicornclub.dev)
Many developers find modern front-end frameworks hard to use. This is because technologies change quickly, and web apps need to be: fast, interactive, easy to maintain
[**Masonry and reading order**](https://rachelandrew.co.uk/archives/2024/05/26/masonry-and-reading-order/?utm_source=unicornclub.dev&utm_medium=newsletter&utm_campaign=unicornclub.dev&ref=unicornclub.dev)
CSS masonry is an example of an automatic layout method, where the developer of the site doesn’t have control over where the items end up
[**A rare use case for em units**](https://bradfrost.com/blog/post/a-rare-use-case-for-em-units/?utm_source=unicornclub.dev&utm_medium=newsletter&utm_campaign=unicornclub.dev&ref=unicornclub.dev)
text-decoration-offset is a good use case for em units. Most of the time we favor rems over ems.
### **💭 Fun Fact**
******The "em" Unit's Typographic Roots****** - The `em` unit in CSS has its origins in typography, where it was traditionally used to measure the width of the letter "M" in typesetting. This unit has evolved in web design to represent the size of the font in a given context, making it a relative unit that adjusts based on the font size of its parent element.
## 🎨 Design
[**Only 30 seconds to reject your portfolio?**](https://uxdesign.cc/only-30-seconds-to-reject-your-portfolio-8cb14ac70674?utm_source=unicornclub.dev&utm_medium=newsletter&utm_campaign=unicornclub.dev&ref=unicornclub.dev)
Common mistakes designers should avoid to make the first cut in UX hiring.
[**Is Canva Getting Good?**](https://johannesippen.com/2024/canva-goes-professional/?utm_source=unicornclub.dev&utm_medium=newsletter&utm_campaign=unicornclub.dev&ref=unicornclub.dev)
Canva. if you talk to a professional designer about Canva, the first reaction is usually an eye roll, followed by a joke about Word Art (Anyone remember Office 2000?).
[**Presenting UX Research And Design To Stakeholders: The Power Of Persuasion**](https://www.smashingmagazine.com/2024/06/presenting-ux-research-design-stakeholders/?utm_source=unicornclub.dev&utm_medium=newsletter&utm_campaign=unicornclub.dev&ref=unicornclub.dev)
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1,886,257 | Who Can Benefit from Driving Training in Prince William County? | riving is a critical skill in today's fast-paced world, offering independence and convenience.... | 0 | 2024-06-12T22:57:16 | https://dev.to/ezdrivingschool_onlineeva/who-can-benefit-from-driving-training-in-prince-william-county-2c7i | riving is a critical skill in today's fast-paced world, offering independence and convenience. Whether you're a teenager eager to hit the road for the first time or an adult looking to enhance your driving skills, driving training is essential. Prince William County offers excellent opportunities for driving training, catering to various needs and skill levels. This article explores who can benefit from **[driving training in Prince William County](https://ezdrivingschoolonlineva.com/area/online-driving-courses-prince-william-county-va/)** and highlights the easy way to learn driving in Bedford City.
Teenagers and First-Time Drivers
For teenagers and first-time drivers, driving training is a crucial step toward gaining independence and ensuring safety on the road. In Prince William County, driving schools provide comprehensive courses that cover everything from basic vehicle operation to advanced driving techniques. These programs are designed to equip new drivers with the knowledge and skills necessary to navigate the roads confidently and safely.
Building a Strong Foundation
Driving training in Prince William County offers a structured curriculum that helps teenagers build a strong foundation in driving. The courses typically include both classroom instruction and practical, behind-the-wheel experience. This combination ensures that new drivers understand the rules of the road, traffic signs, and safe driving practices before they get behind the wheel.
Enhancing Confidence
One of the significant benefits of driving training for teenagers is the boost in confidence. Driving instructors in Prince William County are trained to be patient and supportive, creating a positive learning environment. This support helps new drivers overcome their initial fears and anxieties, making the learning process smoother and more enjoyable.
Adults Seeking Skill Improvement
Driving is a skill that requires continuous improvement and adaptation to changing road conditions and vehicle technologies. For adults in Prince William County, driving training offers an opportunity to enhance their existing skills and learn new ones. Whether you want to refresh your knowledge after a long break from driving or need to adapt to new driving environments, professional training can make a significant difference.
Adapting to Modern Vehicles
Modern vehicles come with advanced technologies that can be overwhelming for some drivers. Driving training in Prince William County includes instruction on using these new features, such as advanced driver-assistance systems (ADAS), parking sensors, and navigation systems. Understanding how to use these technologies effectively can improve driving safety and convenience.
Addressing Bad Habits
Many experienced drivers develop bad habits over time, such as improper lane usage, not signaling, or distracted driving. Professional driving instructors can help identify and correct these habits, promoting safer driving practices. By enrolling in a driving training program, adults can refine their skills and become more responsible drivers.
Seniors Aiming to Maintain Independence
For senior citizens, maintaining the ability to drive is often linked to independence and quality of life. Driving training in Prince William County is tailored to meet the unique needs of older adults, helping them stay safe on the road while preserving their independence.
Refreshing Knowledge
As driving regulations and road conditions change, it’s essential for seniors to stay updated. Driving training programs offer refresher courses that cover the latest traffic laws and safe driving practices. These courses are designed to be accessible and considerate of the physical and cognitive changes that may come with aging.
Improving Reaction Time
Reaction time can slow down with age, impacting driving performance. Driving training in Prince William County includes exercises and techniques to improve reaction time and overall driving skills. By focusing on these areas, seniors can continue to drive safely and confidently.
New Residents Adapting to Local Roads
Moving to a new area can present challenges for drivers who are unfamiliar with local roadways and traffic patterns. For new residents in Prince William County, driving training offers an opportunity to get acquainted with the local driving environment and ensure a smooth transition.
Understanding Local Traffic Patterns
Every region has its unique traffic patterns and road layouts. Driving training in Prince William County provides new residents with the knowledge and experience needed to navigate these local nuances. Instructors familiarize learners with common routes, busy intersections, and any region-specific driving rules.
Building Local Driving Confidence
New residents often feel anxious about driving in an unfamiliar place. Professional driving training helps build confidence by providing guided practice and expert insights into the local driving scene. This support is crucial for developing a sense of comfort and assurance on the road.
Commercial Drivers Seeking Certification
For individuals aspiring to become commercial drivers, obtaining proper certification is a mandatory step. Driving training in Prince William County includes specialized programs for commercial driving, ensuring that candidates meet the required standards and are well-prepared for their roles.
Meeting Certification Requirements
Commercial driving involves stringent certification requirements, including written exams and practical tests. Driving training programs in Prince William County are designed to help candidates meet these requirements through comprehensive preparation. The curriculum covers all necessary topics, from vehicle operation to safety protocols.
Enhancing Professional Skills
Beyond certification, professional driving training focuses on enhancing the skills needed for a successful career in commercial driving. This includes advanced driving techniques, defensive driving, and proper vehicle maintenance. By completing these programs, aspiring commercial drivers can improve their employability and job performance.
Parents Preparing to Teach Their Teens
Parents play a crucial role in teaching their teens how to drive. However, many parents feel unprepared for this responsibility. Driving training in Prince William County offers programs specifically designed for parents, providing them with the tools and knowledge needed to effectively teach their teens.
Understanding Instruction Techniques
Teaching a teenager to drive requires more than just knowledge of driving; it involves understanding effective instruction techniques. Driving training programs for parents cover these techniques, ensuring that parents can communicate clearly and provide constructive feedback to their teens.
Staying Informed About Current Practices
Driving regulations and practices evolve over time. Parents who learned to drive many years ago may not be familiar with current standards. By participating in a driving training program, parents can stay informed about the latest practices and ensure they are teaching their teens the most up-to-date information.
Drivers with Anxiety or Phobia
Driving anxiety or phobia can significantly impact a person's ability to drive safely. For those in Prince William County dealing with such challenges, specialized driving training programs offer support and strategies to overcome these issues.
Building Gradual Exposure
Overcoming driving anxiety often requires gradual exposure to driving situations. Professional driving instructors are trained to work with anxious learners, starting with low-stress environments and progressively moving to more challenging scenarios. This approach helps build confidence and reduce anxiety over time.
Providing Coping Strategies
In addition to practical driving skills, these specialized programs offer coping strategies to manage anxiety while driving. Techniques such as deep breathing, positive visualization, and mindfulness can make a significant difference in helping anxious drivers feel more comfortable behind the wheel.
Easy Way to Learn Driving in Bedford City
While Prince William County offers extensive driving training programs, those in Bedford City also have access to convenient and effective driving instruction. Learning to drive in Bedford City is made easier through well-structured courses and experienced instructors.
Comprehensive Learning Programs
Driving schools in Bedford City provide comprehensive learning programs that cover all aspects of driving. From theoretical knowledge to practical driving experience, these courses are designed to equip learners with the necessary skills to drive safely and confidently.
Experienced and Supportive Instructors
The key to an easy way to learn driving in Bedford City lies in the quality of the instructors. Experienced and supportive instructors create a positive learning environment, helping learners overcome challenges and gain confidence. Their guidance ensures that learners are well-prepared for both the driving test and real-world driving scenarios.
Flexible Scheduling
Driving training programs in Bedford City offer flexible scheduling options to accommodate learners' busy lives. Whether you prefer evening classes, weekend sessions, or intensive courses, there are options available to suit your needs. This flexibility makes it easier for everyone to find time for driving training.
Conclusion
Driving training in Prince William County is beneficial for a wide range of individuals, from teenagers and first-time drivers to seniors and commercial driving aspirants. The comprehensive programs offered cater to various needs, ensuring that all participants can improve their driving skills and confidence. Additionally, for those in Bedford City, learning to drive is made easier through structured programs and supportive instructors. Whether you're looking to start driving, refresh your skills, or adapt to new driving environments, professional driving training is an invaluable resource.
| ezdrivingschool_onlineeva | |
1,898,028 | Two Ideas from the Lean Movement | It’s been 10 years since I first started learning about DevOps. I was in some airport waiting to go... | 0 | 2024-06-23T18:31:18 | https://burnskp.dev/2024/06/12/two-ideas-from-the-lean-movement/ | devops | ---
title: Two Ideas from the Lean Movement
published: true
date: 2024-06-12 20:10:03 UTC
tags: devops
canonical_url: https://burnskp.dev/2024/06/12/two-ideas-from-the-lean-movement/
---
It’s been 10 years since I first started learning about DevOps. I was in some airport waiting to go home from a pentest and I was looking through ruby and chef videos on youtube when I came across [Jez Humble’s ChefConf 2015 Keynote](https://www.youtube.com/watch?v=L1w2_AY82WY) and it blew me away.
I started my career as a Linux and Solaris sysadmin and moved into security consulting about a decade later. I must have heard some mention of DevOps before then. I had a copy of [The Phoenix Project](https://itrevolution.com/product/the-phoenix-project/), but didn’t get that far into it. It reminded me too much of my old jobs and I didn’t want to read a book that mirrored my past experiences.
I’ve since watched countless hours of conference talks, attended multiple DevOps Days cons, and read multiple books on DevOps. This led me to the lean manufacturing movement and books by Demming and Goldratt. There’s two ideas that have stayed with me since I first heard them.
# Taking Advantage of Technology Requires Change
[Beyond the Goal](https://www.audible.com/pd/Beyond-the-Goal-Audiobook/B002V1LYO2) is an amazing set of lectures from Eliyahu M. Goldratt. While there’s a few topics he goes over, the first one is the most applicable to my job. Dan North also did a talk on it in 2017 called [How to Break the Rules](https://www.youtube.com/watch?v=hZFShSjAhlQ), which provides more modern examples.
_“Technology can bring benefit if, and only if, it diminishes a limitation” – Eliyahu M. Goldratt_
Eliyahu starts off with this quote, then provides four questions we can ask ourselves relating to this.
1. What is the power of the technology?
2. What limitation does the technology diminish?
3. What rules enabled us to manage this limitation?
4. What new rules will we need?
The idea is that when we start working we find a set of limitations that we have. In order to deal with these limitations we create rules. These rules help us cope with the limitations and provide a framework we can use to handle them. Before teleworking became common we were limited to getting jobs that we could reasonable get to every workday. If there was a job in another state we normally had to move if we wanted to work there. With the rise of high speed internet and the numerous communication methods that we now have this limitation has diminished. Some jobs no longer require being there in person to complete. This allows us to change the rules to allow people the ability to work from home.
This also means that we should take a look at anything we implement and determine what it provides and what limitations does it diminish. Let’s say your team did integration testing once a month due to issues with the tech stack and the amount of hardware and cooperation required. It’s then decided that they want to bring in a platform team and develop a build pipeline that can do an end to end integration test every night. You’ve gone from being able to do this task 12 times a year, to 365 times. This is great news!
However, there are some questions you should ask yourself in this situation:
- Did anyone look at what rules were in place due to only being able to do this once a month?
- Did someone take a look at all the meetings and change approvals that were implemented to deal with the difficulty with the old way?
- Were you able to change those rules to take better advantage of the technology?
- If you don’t change how you perform your work to take advantage of the new technology, then what benefit did the new technology actually give you? It may not be needed for your day to day feature implementation side, but any time you change your teams workflow you should ask yourself Eliyahu’s four questions listed at the start of this section.
# Provide Context, Not Solutions
_“It is not enough to do your best; you must know what to do and then do your best” – W. Edwards Demming_
There’s a common pattern I see all over. A system gets designed by managers and architects and then the solutions are handed down to the workers to implement. The people doing the implementation aren’t given the time or leeway to learn what they’re doing or how to do it. They’re not even given much context beyond the solution. Maybe they’ve never even been taught that they should have more than this. The solutions are created based on previous experiences and grand idea conference room designing. The design is implemented. Tested based on the prescribed solution. It goes into production and breaks. It isn’t designed to handle the scale, or it has a bad data model. Maybe the solution provided had nothing to do with what the problem actually was.
I’m not sure how anyone can expect someone to succeed if they don’t know what they’re doing. While this does relate to people needing to hone their skills outside of work, I’m mostly looking at it from the perspective of providing context and the ability to learn and experiment. People are not mindless machines designed to perform a singular task. They need to know why they’re doing a task. Management needs to provide context. Demming talks about this in [one of his interviews](https://youtu.be/tsF-8u-V4j4?t=211).
Provide context, not solutions. By giving your employees the ability to grow and the opportunity to have their say in the work they perform, you’ll find greatness. They will generally be able to make better decisions because they are closer to the problem and have more hands-on information than the people who white boarded it 4 months prior to the start of the project. | burnskp |
1,886,254 | ☁️Cloud Computing☁️😺 | This is a submission for DEV Computer Science Challenge v24.06.12: One Byte Explainer. ... | 0 | 2024-06-12T22:45:54 | https://dev.to/banega00/cloud-computing-2op7 | devchallenge, cschallenge, computerscience, beginners | _This is a submission for DEV Computer Science Challenge v24.06.12: One Byte Explainer._
## Explainer
No more memory space on your phone to download cat memes?😿 Send your cats to Cloud! Thanks to Cloud Computing you can use someone else's resources to do so, your cat memes will be waiting for you to access them over the network anytime and anywhere. ☁️🐈
## Additional Context
Real problems call for real solutions. Jokes aside, I think this is a funny but pretty memorable analogy for explaining the concept of cloud computing. | banega00 |
1,886,158 | Understanding Terraform: A Guide to Effective IaC Practices | What is Terraform? Terraform is an infrastructure as code (IaC) tool that allows you to... | 0 | 2024-06-12T22:38:45 | https://dev.to/hassan_aftab/understanding-terraform-a-guide-to-effective-iac-practices-28pn | programming, devops, terraform, infrastructureascode | ## What is Terraform?
<br>
Terraform is an infrastructure as code (IaC) tool that allows you to build, change, and version cloud and on-premises resources safely and efficiently.
With Terraform, you define your infrastructure using human-readable configuration files, which can be **versioned, reused, and shared**.
It works with a wide range of platforms and services through their APIs, enabling you to manage both low-level components (such as compute instances, storage, and networking) in a consistent manner.
<br>
### The 3 Stage Workflow:
<br>
#### **The Coding Stage**:
Define resources across one or multiple cloud providers and services in your configuration files, depending on your requirements.
Here is a sample project structure:
```bash
.
├── bicep
│ ├── deploy.ps1
│ ├── init.bicep
│ ├── params
│ │ ├── dev.bicepparam
│ │ └── test.bicepparam
│ └── storage.bicep
├── LICENSE
├── Makefile
├── README.md
└── terraform
├── modules
│ ├── container_app
│ │ ├── main.tf
│ │ ├── outputs.tf
│ │ └── variables.tf
│ ├── container_app_environment
│ │ ├── main.tf
│ │ ├── outputs.tf
│ │ └── variables.tf
│ ├── container_registry
│ │ ├── main.tf
│ │ ├── outputs.tf
│ │ └── variables.tf
│ ├── resource_group
│ │ ├── main.tf
│ │ ├── outputs.tf
│ │ └── variables.tf
│ ├── subnet
│ │ ├── main.tf
│ │ ├── outputs.tf
│ │ └── variables.tf
│ ├── subnet_network_security_group_association
│ │ ├── main.tf
│ │ ├── outputs.tf
│ │ └── variables.tf
│ └── virtual_network
│ ├── main.tf
│ ├── outputs.tf
│ └── variables.tf
└── resources
├── backend.tf
├── data.tf
├── main.tf
├── outputs.tf
├── provider.tf
├── tfvars
│ ├── dev.tfvars
│ ├── eun_region.tfvars
│ └── tags.tfvars
└── variables.tf
```
<br>
You can however, code the entire thing in a single file if you want, but as we all know, it is considered as a best practice, to adhere to separation of concerns
Lets breakdown the <a href="https://github.com/hassanaftab93/terraform-example">project</a> structure:
<br>
- directories:
- bicep
- terraform
- terraform/module
- terraform/resources
<br>
- files:
- all files in directories inside terraform/modules/ contain modules for individual resources
<br>
```terraform
# backend.tf
# Here we define the provider to use for this directory
terraform {
backend "azurerm" {
storage_account_name = "storageAccountName"
container_name = "tfstates"
resource_group_name = "resourceGroupName"
key = "resources.tfstate"
}
}
```
```terraform
# data.tf
# Here we define the data sources to use for this directory
data "terraform_remote_state" "resources" {
backend = "azurerm"
config = {
storage_account_name = "storageAccountName"
container_name = "tfstates"
resource_group_name = "resourceGroupName"
key = "resources.tfstate"
}
}
# In this case, we use the data source to get the existing resource group
data "azurerm_resource_group" "existing" {
name = "resourceGroupName"
}
```
As shown above, in the directory structure, the modules are defined in the `terraform/modules` directory and the resources are defined in the `terraform/resources` directory. The main codebase of this project resides in the `terraform/resources/main.tf` file.
<br>
Main things to note in the `terraform/resources/main.tf` file:
<br>source - defines the module to use
<br>module - defines the resources to create
<br>The use of `data.azurerm_resource_group.existing.location` as well as `data.azurerm_resource_group.existing.name` to get the location and name of the resource group
<br>The use of depend_on to ensure that the resources are created before the module is executed
<br>Notice the use of $(acrServer) and $(acrUsername) and $(acrPassword) in the container_registry_server, container_registry_username and container_registry_password respectively.
These variables are defined in Pipelines. Since this information is sensitive, we are hiding it in the codebase and storing these secrets in pipeline variable groups/secrets
Let's take a look at the contents below:
```terraform
# main.tf
# Here we define the resources to use for this project
# Defining the network security group
module "network_security_group" {
source = "../modules/network_security_group"
name = "project${var.environment}nsg"
location = data.azurerm_resource_group.existing.location
resource_group_name = data.azurerm_resource_group.existing.name
rules = [
{
name = "nsg-rule-1"
priority = 100
direction = "Inbound"
access = "Allow"
protocol = "*"
source_port_range = "*"
destination_port_range = "*"
source_address_prefix = "*"
destination_address_prefix = "*"
},
{
name = "nsg-rule-2"
priority = 101
direction = "Outbound"
access = "Allow"
protocol = "*"
source_port_range = "*"
destination_port_range = "*"
source_address_prefix = "*"
destination_address_prefix = "*"
}
]
depends_on = [data.azurerm_resource_group.existing]
tags = merge(var.tags)
}
# Defining the virtual network to use in resources
module "virtual_network" {
source = "../modules/virtual_network"
name = "project${var.environment}vnet"
location = data.azurerm_resource_group.existing.location
resource_group_name = data.azurerm_resource_group.existing.name
address_space = ["10.0.0.0/16"]
depends_on = [data.azurerm_resource_group.existing, module.network_security_group.this]
tags = merge(var.tags)
}
# Defining the subnet that will be used to create resources under, later on.
module "subnet" {
source = "../modules/subnet"
name = "project${var.environment}subnet"
resource_group_name = data.azurerm_resource_group.existing.name
virtual_network_name = module.virtual_network.virtual_network_name
subnet_address_prefix = ["10.0.1.0/24"]
service_endpoints = ["Microsoft.Storage", "Microsoft.Web"]
delegation_name = "delegation"
service_delegation_name = "Microsoft.App/environments"
service_delegation_actions = ["Microsoft.Network/virtualNetworks/subnets/join/action", "Microsoft.Network/virtualNetworks/subnets/prepareNetworkPolicies/action"]
depends_on = [data.azurerm_resource_group.existing, module.virtual_network.this, module.network_security_group.this]
}
# Defining the container app environment, notice the use of module.subnet.subnet_id , this is how we can reference the subnet_id from the subnet module.
module "container_app_environment" {
source = "../modules/container_app_environment"
resource_group_name = data.azurerm_resource_group.existing.name
location = data.azurerm_resource_group.existing.location
name = "project-${var.environment}-cntr-env"
log_analytics_workspace_id = module.log_analytics_workspace.log_analytics_workspace_id
infrastructure_subnet_id = module.subnet.subnet_id
internal_load_balancer_enabled = false
depends_on = [data.azurerm_resource_group.existing, module.subnet.this]
tags = merge(var.tags)
}
# Defining the container registry
module "container_registry" {
source = "../modules/container_registry"
resource_group_name = data.azurerm_resource_group.existing.name
location = data.azurerm_resource_group.existing.location
name = "project${var.environment}cr"
sku = "Standard"
is_admin_enabled = true
is_public_network_access_enabled = true
depends_on = [data.azurerm_resource_group.existing, module.key_vault.this]
tags = merge(var.tags)
}
# Defining the container apps that will be created under the container app environment created earlier
module "container_app" {
source = "../modules/container_app"
resource_group_name = data.azurerm_resource_group.existing.name
container_app_environment_id = module.container_app_environment.Environment_ID
container_registry_server = "$(acrServer)"
container_registry_username = "$(acrUsername)"
container_registry_password = "$(acrPassword)"
container_apps = [
# Notice the use of $(containerAppSecretKey) and $(containerAppSecretValue) in the secret_name and secret_value respectively
{
name = "containerapp1-${var.environment}"
image = "mcr.microsoft.com/azuredocs/containerapps-helloworld:latest"
cpu = 0.25
memory = "0.5Gi"
target_port = 8080
transport = "http2"
external_enabled = true
allow_insecure_connections = false
secret_name = "$(containerAppSecretKey)"
secret_value = "$(containerAppSecretValue)"
},
{
name = "containerapp2-${var.environment}"
image = "mcr.microsoft.com/azuredocs/containerapps-helloworld:latest"
cpu = 0.25
memory = "0.5Gi"
target_port = 8080
transport = "auto"
external_enabled = true
allow_insecure_connections = false
secret_name = "$(containerAppSecretKey)"
secret_value = "$(containerAppSecretValue)"
}
]
depends_on = [data.azurerm_resource_group.existing, module.container_app_environment.this, module.container_registry.this]
tags = merge(var.tags)
}
# Defining the network security group association
module "subnet_nsg_association" {
source = "../modules/subnet_network_security_group_association"
subnet_id = module.subnet.subnet_id
network_security_group_id = module.network_security_group.id
depends_on = [data.azurerm_resource_group.existing, module.subnet.this, module.network_security_group.this]
}
```
In the block below, are the contents of output.tf, which contains all the outputs we want to get when the terraform code is run in the terminal / pipeline.
This can include details such as IPs of services being created, fqdns, etc.
One thing to keep in mind is, since we are using a modular based approach, these outputs must first be exported from an output.tf file inside the module itself, before the implementation of the module that actually outputs it during the run.
```terraform
# outputs.tf
# Here we define the outputs to use for this directory
# Container App Environment
output "container_app_environment_default_domain" {
value = module.container_app_environment.Default_Domain
}
output "container_app_environment_docker_bridge" {
value = module.container_app_environment.Docker_Bridge_CIDR
}
output "container_app_environment_environment_id" {
value = module.container_app_environment.Environment_ID
}
output "container_app_environment_static_ip_address" {
value = module.container_app_environment.Static_IP_Address
}
# Container Apps
output "container_app_latest_fqdn" {
value = module.container_app.Latest_Revision_Fqdn
}
output "container_app_outbound_ips" {
value = module.container_app.Outbound_Ip_Addresses
}
# Container Registry
output "container_registry_id" {
value = module.container_registry.id
}
output "container_registry_sku" {
value = module.container_registry.sku
}
output "container_registry_registry_server" {
value = module.container_registry.registry_server
}
output "container_registry_admin_enabled" {
value = module.container_registry.admin_enabled
}
output "container_registry_admin_username" {
value = module.container_registry.admin_username
sensitive = true
}
output "container_registry_admin_password" {
value = module.container_registry.admin_password
sensitive = true
}
```
In the next block, are the contents of provider.tf
We have used `skip_provider_registration = true` to skip the provider registration, as sometimes during a Pipeline run, it can causes issues if terraform checks for registered providers.
Furthermore, here we define the minimum version of the provider we are using as well as the required version of the Terraform CLI.
```terraform
# provider.tf
# Here we define the providers to use for this directory
provider "azurerm" {
features {}
skip_provider_registration = true
}
terraform {
required_version = ">= 1.7.5"
required_providers {
azurerm = {
source = "hashicorp/azurerm"
version = ">=3.96.0"
}
}
}
```
In the next block, are the contents of tfvars/dev.tf
As discussed before, sensitive values are stored in pipeline variable groups/secrets. In this case `sql_administrator_login` and `sql_administrator_login_password`.
```terraform
# tfvars/dev.tf
# This file defines the variables to use for this project for the dev environment
project_name = "Project"
environment = "dev"
administrator_login = "$(sql_administrator_login)"
administrator_login_password = "$(sql_administrator_login_password)"
```
Similarly:
```terraform
# tfvars/eun_region.tf
region_name = "northeurope"
region_short = "eun"
```
In the last variables file, are the contents of tfvars/tags.tf, which defines the tags to be applied to the resources. Back in the main.tf file, we used this `tags = merge(var.tags)` key-value pair approach to define the tags.
```terraform
# tfvars/tags.tf
tags = {
ServiceName = ""
Department = "Cloud"
Environment = "dev"
SubEnvironment = "nonProd"
SystemName = ""
}
```
And finally the variables file that contains the variables and their types
```terraform
# variables.tf
variable "region_short" {
type = string
description = "Short name of region used in project"
}
variable "region_name" {
type = string
description = "Long name of region used in project"
}
variable "project_name" {
description = "Project name"
}
variable "environment" {
type = string
description = "Environment name"
}
variable "tags" {
type = map(string)
default = {
ServiceName = ""
Department = ""
Environment = ""
SubEnvironment = ""
SystemName = ""
}
}
variable "administrator_login" {
type = string
description = "Administrator login"
sensitive = true
}
variable "administrator_login_password" {
type = string
description = "Administrator login password"
sensitive = true
}
```
<br>
#### **The Plan Stage**
In this stage, we are done with defining Infrastructure as Code configurations, now we need Terraform to generate an execution plan based on these configurations and existing infrastructure, describing the changes it will make.
Before we go ahead and generate a plan, it is considered a good practice to make sure your code is valid and there are no syntax errors, or referencing errors.
This can be done by switching to your trusty CLI.. again, and running:
```terraform
# This command validates your code and makes sure it's good to go
terraform validate
# And it's just as easy to make your code look much more cleaner with just one command again
terraform fmt --recursive
```
This `terraform fmt --recursive` command formats the current directory as well the child directories and all .tf and .tfvars files, and properly indents all code.
<br>
Below we can see our code is valid!
<br>
<br>
Finally we can generate a plan by running a simple command
```terraform
# Command to generate plan
terraform plan -o dev.tfplan
# In our case, we are using tfvars file in a directory called tfvars/, now we will need to modify the command a little bit to get the same result
terraform plan -var-file=tfvars/dev.tfvars -var-file=tfvars/eun_region.tfvars -var-file=tfvars/tags.tfvars -out=dev.tfplan
```
<br>
Sample output can such as:
```terraform
# module.subnet.azurerm_subnet.this will be updated in-place
~ resource "azurerm_subnet" "this" {
id = "/subscriptions/GUID_HERE/resourceGroups/project-dev/providers/Microsoft.Network/virtualNetworks/project-vnet-dev/subnets/project-subnet-dev"
name = "project-subnet-dev"
# (10 unchanged attributes hidden)
~ delegation {
name = "project-subnet-delegation-dev"
~ service_delegation {
~ actions = [
"Microsoft.Network/virtualNetworks/subnets/join/action",
+ "Microsoft.Network/virtualNetworks/subnets/prepareNetworkPolicies/action",
]
name = "Microsoft.App/environments"
}
}
}
Plan: 1 to add, 1 to change, 0 to destroy.
Changes to Outputs:
~ storage_account_name = "projectblobdev" -> "project1blobdev"
+ storage_account_primary_key = (sensitive value)
```
These changes are basically compared with a .tfstate file that can exist in your local machine or on the cloud, hosted in a s3 bucket or blob storage.
In our example above, we used a blob storage service to host the tfstate file.
<br>
#### **The Apply Stage**
Upon approval of the plan generated in the last step, Terraform applies the proposed changes in the correct order, respecting resource dependencies.
```terraform
# Apply command for deploying the infrastructure
terraform apply dev.tfplan
```
<br>
This will then finally, deploy your infrastructure to the cloud. You can however, if needed, destroy the infrastructure when done with your usecase.
```terraform
# Destroy it all by:
terraform destroy -var-file=tfvars/dev.tfvars -var-file=tfvars/eun_region.tfvars -var-file=tfvars/tags.tfvars
```
All in all, It’s a powerful tool for managing infrastructure, allowing you to track changes, maintain consistency, and avoid manual errors.
And that's not all, at the same time it also ensures, controlled costs in cloud infrastructure, since you can easily create and destroy infrastructure with simple commands.
This automation can be taken further with Pipelines and gitflow that triggers based on branch that reflects a certain environment.. but that's a topic for another day :D
You can find the source code by clicking <a href="https://github.com/hassanaftab93/terraform-example/tree/main">Here</a>
I hope this article was a fun read and helped you gain some deeper insights into terraform modules and best practices.
Thankyou for the read! | hassan_aftab |
1,886,252 | The Ultimate Guide to Professional Legal Translation Services | Welcome to our comprehensive guide on professional legal translation services. At our agency, we... | 0 | 2024-06-12T22:37:48 | https://dev.to/alexaandrew/the-ultimate-guide-to-professional-legal-translation-services-jkb | Welcome to our comprehensive guide on professional legal translation services. At our agency, we understand the critical importance of accurate and reliable translations in the legal field. Whether you’re a law firm, corporate entity, or government agency, we are here to meet your legal translation needs with precision and expertise.
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1,886,251 | Clean Code With AI | Mastering Clean Code with ChatGPT and Gemini TL;DR: This is my talk a at Tech Excellence on... | 18,654 | 2024-06-12T22:36:57 | https://dev.to/mcsee/clean-code-with-ai-4kck | cleancode, ai, chatgpt, refactoring | *Mastering Clean Code with ChatGPT and Gemini*
> TL;DR: This is my talk a at Tech Excellence on combining Artificial Intelligence and Clean Code
# Summary
How can you leverage ChatGPT, Gemini, Copilot and other assistants to write clean code? What instructions should you provide them? How do you configure them to assist you?
Code assistants were trained on datasets that were not so well curated. You often ask them for solutions that meet requirements but do not reflect good designs. However, with some instructions, you can indicate how we want them to assist you. In this way, their solutions will comply with good development practices and be customized according to your rules.
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{% youtube 99GuXTIW0R4 %} | mcsee |
1,886,204 | shadcn-ui/ui codebase analysis: Dashboard example explained. | In this article, we will learn about Dashboard example in shadcn-ui/ui. This article consists of the... | 0 | 2024-06-12T20:51:12 | https://dev.to/ramunarasinga/shadcn-uiui-codebase-analysis-dashboard-example-explained-42a1 | javascript, nextjs, opensource, shadcnui | In this article, we will learn about [Dashboard](https://ui.shadcn.com/examples/dashboard) example in shadcn-ui/ui. This article consists of the following sections:
1. Where is dashboard folder located?
2. What is in dashboard folder?
3. Components used in dashboard example.
Where is dashboard folder located?
----------------------------------
Shadcn-ui/ui uses app router and [dashboard folder](https://github.com/shadcn-ui/ui/tree/main/apps/www/app/(app)/examples/dashboard) is located in [examples](https://github.com/shadcn-ui/ui/tree/main/apps/www/app/(app)/examples) folder, which is located in [(app)](https://github.com/shadcn-ui/ui/tree/main/apps/www/app/(app)), [a route group in Next.js](https://medium.com/@ramu.narasinga_61050/app-app-route-group-in-shadcn-ui-ui-098a5a594e0c).
What is in dashboard folder?
----------------------------
As you can see from the above image, we have components folder, page.tsx.
[page.tsx](https://github.com/shadcn-ui/ui/blob/main/apps/www/app/(app)/examples/dashboard/page.tsx) is loaded in place of [{children} in examples/layout.tsx](https://github.com/shadcn-ui/ui/blob/main/apps/www/app/(app)/examples/layout.tsx#L55).
Below is the code picked from mail/page.tsx
```js
import { Metadata } from "next"
import Image from "next/image"
import { Button } from "@/registry/new-york/ui/button"
import {
Card,
CardContent,
CardDescription,
CardHeader,
CardTitle,
} from "@/registry/new-york/ui/card"
import {
Tabs,
TabsContent,
TabsList,
TabsTrigger,
} from "@/registry/new-york/ui/tabs"
import { CalendarDateRangePicker } from "@/app/(app)/examples/dashboard/components/date-range-picker"
import { MainNav } from "@/app/(app)/examples/dashboard/components/main-nav"
import { Overview } from "@/app/(app)/examples/dashboard/components/overview"
import { RecentSales } from "@/app/(app)/examples/dashboard/components/recent-sales"
import { Search } from "@/app/(app)/examples/dashboard/components/search"
import TeamSwitcher from "@/app/(app)/examples/dashboard/components/team-switcher"
import { UserNav } from "@/app/(app)/examples/dashboard/components/user-nav"
export const metadata: Metadata = {
title: "Dashboard",
description: "Example dashboard app built using the components.",
}
export default function DashboardPage() {
return (
<>
<div className="md:hidden">
<Image
src="/examples/dashboard-light.png"
width={1280}
height={866}
alt="Dashboard"
className="block dark:hidden"
/>
<Image
src="/examples/dashboard-dark.png"
width={1280}
height={866}
alt="Dashboard"
className="hidden dark:block"
/>
</div>
<div className="hidden flex-col md:flex">
<div className="border-b">
<div className="flex h-16 items-center px-4">
<TeamSwitcher />
<MainNav className="mx-6" />
<div className="ml-auto flex items-center space-x-4">
<Search />
<UserNav />
</div>
</div>
</div>
<div className="flex-1 space-y-4 p-8 pt-6">
<div className="flex items-center justify-between space-y-2">
<h2 className="text-3xl font-bold tracking-tight">Dashboard</h2>
<div className="flex items-center space-x-2">
<CalendarDateRangePicker />
<Button>Download</Button>
</div>
</div>
<Tabs defaultValue="overview" className="space-y-4">
<TabsList>
<TabsTrigger value="overview">Overview</TabsTrigger>
<TabsTrigger value="analytics" disabled>
Analytics
</TabsTrigger>
<TabsTrigger value="reports" disabled>
Reports
</TabsTrigger>
<TabsTrigger value="notifications" disabled>
Notifications
</TabsTrigger>
</TabsList>
<TabsContent value="overview" className="space-y-4">
<div className="grid gap-4 md:grid-cols-2 lg:grid-cols-4">
<Card>
<CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
<CardTitle className="text-sm font-medium">
Total Revenue
</CardTitle>
<svg
xmlns="http://www.w3.org/2000/svg"
viewBox="0 0 24 24"
fill="none"
stroke="currentColor"
strokeLinecap="round"
strokeLinejoin="round"
strokeWidth="2"
className="h-4 w-4 text-muted-foreground"
>
<path d="M12 2v20M17 5H9.5a3.5 3.5 0 0 0 0 7h5a3.5 3.5 0 0 1 0 7H6" />
</svg>
</CardHeader>
<CardContent>
<div className="text-2xl font-bold">$45,231.89</div>
<p className="text-xs text-muted-foreground">
+20.1% from last month
</p>
</CardContent>
</Card>
<Card>
<CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
<CardTitle className="text-sm font-medium">
Subscriptions
</CardTitle>
<svg
xmlns="http://www.w3.org/2000/svg"
viewBox="0 0 24 24"
fill="none"
stroke="currentColor"
strokeLinecap="round"
strokeLinejoin="round"
strokeWidth="2"
className="h-4 w-4 text-muted-foreground"
>
<path d="M16 21v-2a4 4 0 0 0-4-4H6a4 4 0 0 0-4 4v2" />
<circle cx="9" cy="7" r="4" />
<path d="M22 21v-2a4 4 0 0 0-3-3.87M16 3.13a4 4 0 0 1 0 7.75" />
</svg>
</CardHeader>
<CardContent>
<div className="text-2xl font-bold">+2350</div>
<p className="text-xs text-muted-foreground">
+180.1% from last month
</p>
</CardContent>
</Card>
<Card>
<CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
<CardTitle className="text-sm font-medium">Sales</CardTitle>
<svg
xmlns="http://www.w3.org/2000/svg"
viewBox="0 0 24 24"
fill="none"
stroke="currentColor"
strokeLinecap="round"
strokeLinejoin="round"
strokeWidth="2"
className="h-4 w-4 text-muted-foreground"
>
<rect width="20" height="14" x="2" y="5" rx="2" />
<path d="M2 10h20" />
</svg>
</CardHeader>
<CardContent>
<div className="text-2xl font-bold">+12,234</div>
<p className="text-xs text-muted-foreground">
+19% from last month
</p>
</CardContent>
</Card>
<Card>
<CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
<CardTitle className="text-sm font-medium">
Active Now
</CardTitle>
<svg
xmlns="http://www.w3.org/2000/svg"
viewBox="0 0 24 24"
fill="none"
stroke="currentColor"
strokeLinecap="round"
strokeLinejoin="round"
strokeWidth="2"
className="h-4 w-4 text-muted-foreground"
>
<path d="M22 12h-4l-3 9L9 3l-3 9H2" />
</svg>
</CardHeader>
<CardContent>
<div className="text-2xl font-bold">+573</div>
<p className="text-xs text-muted-foreground">
+201 since last hour
</p>
</CardContent>
</Card>
</div>
<div className="grid gap-4 md:grid-cols-2 lg:grid-cols-7">
<Card className="col-span-4">
<CardHeader>
<CardTitle>Overview</CardTitle>
</CardHeader>
<CardContent className="pl-2">
<Overview />
</CardContent>
</Card>
<Card className="col-span-3">
<CardHeader>
<CardTitle>Recent Sales</CardTitle>
<CardDescription>
You made 265 sales this month.
</CardDescription>
</CardHeader>
<CardContent>
<RecentSales />
</CardContent>
</Card>
</div>
</TabsContent>
</Tabs>
</div>
</div>
</>
)
}
```
Components used in dashboard example.
-------------------------------------
To find out the components used in this dashboard example, we can simply look at the imports used at the top of page.
```js
import { Button } from "@/registry/new-york/ui/button"
import {
Card,
CardContent,
CardDescription,
CardHeader,
CardTitle,
} from "@/registry/new-york/ui/card"
import {
Tabs,
TabsContent,
TabsList,
TabsTrigger,
} from "@/registry/new-york/ui/tabs"
import { CalendarDateRangePicker } from "@/app/(app)/examples/dashboard/components/date-range-picker"
import { MainNav } from "@/app/(app)/examples/dashboard/components/main-nav"
import { Overview } from "@/app/(app)/examples/dashboard/components/overview"
import { RecentSales } from "@/app/(app)/examples/dashboard/components/recent-sales"
import { Search } from "@/app/(app)/examples/dashboard/components/search"
import TeamSwitcher from "@/app/(app)/examples/dashboard/components/team-switcher"
import { UserNav } from "@/app/(app)/examples/dashboard/components/user-nav"
```
Do not forget the [modular components](https://github.com/shadcn-ui/ui/tree/main/apps/www/app/(app)/examples/dashboard/components) inside dashboard folder.
> _Want to learn how to build shadcn-ui/ui from scratch? Check out_ [_build-from-scratch_](https://github.com/Ramu-Narasinga/build-from-scratch) _and give it a star if you like it._ [_Solve challenges_](https://tthroo.com/) _to build shadcn-ui/ui from scratch. If you are stuck or need help?_ [_solution is available_](https://tthroo.com/build-from-scratch)_._
About me:
---------
Website: [https://ramunarasinga.com/](https://ramunarasinga.com/)
Linkedin: [https://www.linkedin.com/in/ramu-narasinga-189361128/](https://www.linkedin.com/in/ramu-narasinga-189361128/)
Github: [https://github.com/Ramu-Narasinga](https://github.com/Ramu-Narasinga)
Email: [ramu.narasinga@gmail.com](mailto:ramu.narasinga@gmail.com)
References:
-----------
1. [https://github.com/shadcn-ui/ui/tree/main/apps/www/app/(app)/examples/dashboard](https://github.com/shadcn-ui/ui/tree/main/apps/www/app/(app)/examples/dashboard)
2. [https://github.com/shadcn-ui/ui/tree/main/apps/www/app/(app)/examples/dashboard/components](https://github.com/shadcn-ui/ui/tree/main/apps/www/app/(app)/examples/dashboard/components)
3. [https://github.com/shadcn-ui/ui/blob/main/apps/www/app/(app)/examples/dashboard/page.tsx](https://github.com/shadcn-ui/ui/blob/main/apps/www/app/(app)/examples/dashboard/page.tsx) | ramunarasinga |
1,886,250 | [Game of Purpose] Day 25 | Today I managed to animate all of the propellers and can control them all with a single variable.... | 27,434 | 2024-06-12T22:36:37 | https://dev.to/humberd/game-of-purpose-day-25-3kk9 | gamedev | Today I managed to animate all of the propellers and can control them all with a single variable. Yay!
I thought I managed how to get actors of class, but it turns out I query actors in the whole world, and not in my current Blueprint. I need to make more research about it.
Until now when drone spawned the propellers all had the same rotation. Not anymore. Now, when the Drone instance is created I set a random rotation to all of them.
{% embed https://youtu.be/nDoTwItMYso %} | humberd |
1,886,249 | How to make Apache's CloseableHttpAsyncClient explicitly use HTTP/1 or HTTP/2 | In this tutorial, we'll demonstrate how to explicitly use HTTP/1 or HTTP/2 in Apache's... | 0 | 2024-06-12T22:33:06 | https://dev.to/jonathan-dev/how-to-make-apaches-closeablehttpasyncclient-explicitly-use-http1-or-http2-2l2g | java, networking | In this tutorial, we'll demonstrate how to explicitly use HTTP/1 or HTTP/2 in Apache's [CloseableHttpAsyncClient](https://hc.apache.org/httpcomponents-client-5.2.x/current/httpclient5/apidocs/org/apache/hc/client5/http/impl/async/CloseableHttpAsyncClient.html), a base implementation of `HttpAsyncClient` that also implements `ModalClosable`.
You'll need to have this dependency to your `pom.xml`:
```XML
<dependency>
<groupId>org.apache.httpcomponents.client5</groupId>
<artifactId>httpclient5</artifactId>
<version>5.3.1</version>
</dependency>
```
## Deprecated Way
In earlier versions of `httpclient5`, the [HttpAsyncClientBuilder](https://hc.apache.org/httpcomponents-client-5.2.x/current/httpclient5/apidocs/org/apache/hc/client5/http/impl/async/HttpAsyncClientBuilder.html#HttpAsyncClientBuilder--) allowed you to use `setVersionPolicy(org.apache.hc.core5.http2.HttpVersionPolicy versionPolicy)`, where you could pass in `HttpVersionPolicy.FORCE_HTTP_1` or `HttpVersionPolicy.FORCE_HTTP_2`. For example:
```Java
final CloseableHttpAsyncClient client = HttpAsyncClients
.custom()
.useSystemProperties()
.setVersionPolicy(HttpVersionPolicy.FORCE_HTTP_1) //Deprecated
.build();
```
However, in recent versions of `httpclient5`, `setVersionPolicy` is deprecated.
## Best Practice Way
Now, their documentation says that we should use [TlsConfig](https://hc.apache.org/httpcomponents-client-5.2.x/current/httpclient5/apidocs/org/apache/hc/client5/http/config/TlsConfig.html) and connection manager methods instead.
Here's an example:
```Java
TlsConfig tlsHttp1Config = TlsConfig.copy(TlsConfig.DEFAULT).setVersionPolicy(HttpVersionPolicy.FORCE_HTTP_1).build();
//Create a default connection manager
PoolingAsyncClientConnectionManager connectionManager = new PoolingAsyncClientConnectionManager();
connectionManager.setDefaultTlsConfig(tlsHttp1Config);
final CloseableHttpAsyncClient client = HttpAsyncClients
.custom()
.useSystemProperties()
.setConnectionManager(connectionManager)
.build();
```
I hope these examples help if you ever need to use an explicit version of HTTP for your AsyncHttpClients.
| jonathan-dev |
1,886,228 | run.bash & migrate.bash - Pimpe deine .bashrc auf 🔝🔥 | Deine .bashrc Deine .bashrc Datei ist ein Skript, das jedes mal bei deinem Shellzugriff... | 0 | 2024-06-12T21:56:40 | https://dev.to/rubenvoss/runbash-migratebash-pimpe-deine-bashrc-auf-307h | ## Deine .bashrc
Deine .bashrc Datei ist ein Skript, das jedes mal bei deinem Shellzugriff aufgerufen wird. Hier kannst du verschiedene Werte setzen & Dein Leben dadurch leichter machen. Wir werden am Beispiel django jetzt Skripte für dein Projekt entwickeln, die dir den Start deines Projekts erleichtern. Außerdem werden wir deinen `python manage.py migrate` Befehl in einem Container absetzen, das erleichtert dir das Leben bei einem ganz schön langen Befehl.
## Skripte anlegen
Lege bei dir in der Repository auf dem Level deines `docker-compose.yml` folgende Dateien an:
```
touch run.bash migrate.bash
chmod +x run.bash migrate.bash
```
Folgenden Inhalt brauchen deine Skripte:
`run.bash`
Hier kannst du deinen Start-Befehl mit allen Optionen einfügenIch nutze -f, wegen dem speziellen Dateinamen mit --build Baue Ich die images neu vor Containerstart
```
#!/bin/bash
docker compose -f docker-compose.development.yml up --build
```
`migrate.bash`
Mit `exec -it container_name sh -c` können wir unseren migrate Befehl absetzen. Alles in Anführungszeichen wird direkt im Container ausgeführt.
```
docker exec -it meine_app sh -c "python manage.py makemigrations && python manage.py migrate"
```
Weil wir den container namen in der `migrate.bash` nutzen, muss du jetzt noch deine docker-compose Datei anpassen:
```
services:
meine_app:
# wir nutzen den Container Namen in migrate.bash
container_name: meine_app
```
## Skripte in der .bashrc hinzufügen
Füge deine Skripte deiner .bashrc (oder bei mac .zshrc) Hinzu. Die .bashrc / .zshrc befinden sich in deinem home - Verzeichnis.
```
code ~/.bashrc
vi ~/.bashrc
```
Wenn du nun "run" als App-Startbefehl nutzen willst und "migrate" als migrierbefehl, kannst du Folgendes hinzufügen:
```
# selfmade build and run scripts
alias run="./run.bash"
alias migrate="./migrate.bash"
```
Du kannst natürlich deine Skripte anders nennen, und den Befehl zum ausführen der Skripte auch... Es macht aber Sinn, wenn du mehrere Projekte starten / migrieren musst, den Befehl einheitlich zu halten.
Jetzt kannst du nämlich in jedem Projekt ein run.bash hinzufügen. Solange der name des Skriptes "run.bash" bleibt, reicht es jetzt `run` auszuführen - Deine App startet.
Du kannst den Skriptinhalt auch verändern, wenn du bei unterschiedlichen Projekten deine App verschieden Starten willst.
Happy Coden!
Dein Ruben
[Mein Blog](rubenvoss.de)
| rubenvoss | |
1,886,226 | Navigating the Cross-Platform App Development Landscape: What You Need to Succeed in 2024 | Cross-platform app development has become increasingly popular in recent years as businesses seek to... | 0 | 2024-06-12T21:36:11 | https://dev.to/ritesh12/navigating-the-cross-platform-app-development-landscape-what-you-need-to-succeed-in-2024-5365 | Cross-platform app development has become increasingly popular in recent years as businesses seek to reach a wider audience with their mobile applications. This approach allows developers to create apps that can run on multiple operating systems, such as iOS, Android, and Windows, using a single codebase. By doing so, companies can save time and resources while still delivering a high-quality user experience across different devices.
The rise of cross-platform app development can be attributed to the growing demand for mobile applications in various industries, including e-commerce, healthcare, finance, and entertainment. With the increasing diversity of mobile devices and operating systems, businesses are looking for ways to streamline their app development process and reach a larger user base. Cross-platform app development offers a solution to this challenge by enabling developers to write code once and deploy it across multiple platforms, reducing the need for separate development teams and resources for each operating system.
Benefits of Cross-Platform App Development Services
There are several benefits to using cross platform app development services for businesses looking to create mobile applications. One of the main advantages is cost savings, as companies can avoid the need to hire separate development teams for each platform. By using a single codebase, businesses can also save time and resources on maintenance and updates, as changes can be made once and applied across all platforms simultaneously.
Another benefit of cross-platform app development is the ability to reach a wider audience. With apps that can run on multiple operating systems, businesses can tap into different user bases and expand their market reach. This can lead to increased brand visibility and revenue opportunities, as companies can cater to a diverse range of users without having to invest in separate app development for each platform.
Top Cross-Platform App Development Tools and Frameworks
There are several tools and frameworks available for cross-platform app development, each with its own set of features and capabilities. One popular option is Xamarin, which allows developers to write code in C# and deploy it across multiple platforms, including iOS, Android, and Windows. Xamarin offers a range of tools and libraries for building native user interfaces and accessing device-specific features, making it a versatile choice for cross-platform app development.
Another popular framework is React Native, which is based on the JavaScript library React and allows developers to create native mobile apps using a single codebase. With React Native, developers can build high-performance apps with a native look and feel, while still benefiting from the efficiency of cross-platform development. The framework also offers a wide range of pre-built components and a strong community of developers, making it a popular choice for businesses looking to create cross-platform apps.
Factors to Consider When Choosing a Cross-Platform App Development Service
When choosing a cross-platform app development service, businesses should consider several factors to ensure they select the right solution for their needs. One important consideration is the level of support and resources offered by the service provider. Businesses should look for a provider that offers comprehensive support for different platforms and devices, as well as ongoing maintenance and updates to ensure their app remains compatible with the latest operating systems.
Another factor to consider is the performance and user experience of the apps created using the service. Businesses should look for a solution that allows them to build high-quality, native-like apps that deliver a seamless user experience across different devices. This may involve evaluating the tools and frameworks offered by the service provider, as well as considering factors such as speed, responsiveness, and access to device-specific features.
Case Studies of Successful Cross-Platform App Development Projects
There are several examples of successful cross-platform app development projects that demonstrate the benefits of this approach for businesses. One notable case study is that of Airbnb, which used React Native to create its mobile app. By using this framework, Airbnb was able to build a high-quality app with a native look and feel, while still benefiting from the efficiency of cross-platform development. This allowed the company to reach a wider audience and deliver a consistent user experience across different devices.
Another example is that of Walmart, which used Xamarin to create its mobile app for both iOS and Android. By using this framework, Walmart was able to save time and resources on app development, while still delivering a high-performance app with access to device-specific features. This allowed the company to cater to a diverse range of users and provide a seamless shopping experience across different platforms.
Future Trends in Cross-Platform App Development Services
Looking ahead, there are several trends shaping the future of cross-platform app development services. One key trend is the increasing focus on performance and user experience, as businesses seek to deliver high-quality apps that rival native applications. This may involve advancements in tools and frameworks that enable developers to create apps with faster load times, smoother animations, and better access to device-specific features.
Another trend is the growing demand for cross-platform app development in emerging markets, where businesses are looking to reach a diverse range of users with limited resources. This may lead to increased innovation in tools and frameworks that cater to the specific needs of these markets, such as support for low-end devices or limited internet connectivity. As businesses continue to expand their global reach, cross-platform app development services will play an increasingly important role in reaching new audiences.
Conclusion and Recommendations for Cross-Platform App Development Services in 2024
In conclusion, cross-platform app development services offer several benefits for businesses looking to create mobile applications that can run on multiple operating systems. By using a single codebase, companies can save time and resources while still delivering high-quality apps that cater to a diverse range of users. When choosing a cross-platform app development service, businesses should consider factors such as support, performance, and user experience to ensure they select the right solution for their needs.
Looking ahead to 2024, businesses should keep an eye on future trends in cross-platform app development services, such as advancements in performance and user experience, as well as the growing demand for cross-platform apps in emerging markets. By staying informed about these trends and selecting the right service provider, businesses can position themselves for success in the increasingly competitive mobile app market. With the right approach to cross-platform app development, businesses can reach new audiences, save time and resources, and deliver high-quality apps that drive growth and success in 2024 and beyond.
https://nimapinfotech.com/cross-platform-app-development-services/ | ritesh12 | |
1,886,225 | Workflow and Internal Mechanics of CSS with PostCSS and Vite | In modern web development, tools such as Vite and PostCSS are essential for optimizing CSS,... | 0 | 2024-06-12T21:31:46 | https://dev.to/dev_raghvendra/workflow-and-internal-mechanics-of-css-with-postcss-and-vite-9o1 | javascript, beginners, css, vite |
In modern web development, tools such as Vite and `PostCSS` are essential for optimizing CSS, particularly within frameworks like React. This article explores the setup and optimization of CSS using PostCSS plugins like Tailwind CSS and AutoPrefixer within a project powered by Vite.
#### Setting Up Your Project
To begin, setting up your project involves installing necessary packages such as `Tailwind CSS` and `AutoPrefixer`, alongside configuring Vite. Vite, known for its rapid build speed, utilizes configuration files (`vite.config.js`) where you specify how CSS should be processed and bundled.
```
npm install vite tailwindcss autoprefixer postcss
```
#### Writing CSS in JSX Components
Once configured, CSS is integrated directly into `JSX` components. You can import CSS files either module-by-module for each component or globally within the main component of your codebase. The method of importation determines whether these files are processed during Vite's build process.
#### Understanding Vite's Build Process
Commands such as npm run dev or npm run build initiate Vite's build process. Vite scans JSX files for imported CSS files; only those explicitly imported are processed. This underscores the importance of import statements in managing CSS dependencies.
#### PostCSS and Its Role
PostCSS acts as a framework that processes CSS using plugins. When encountering imported CSS, PostCSS creates an Abstract Syntax Tree (AST) of the CSS file, analyzing its structure based on configurations specified in its own `postcss.config.js` file.
```
// postcss.config.js
module.exports = {
plugins: {
tailwindcss: {},
autoprefixer: {},
},
};
```
#### Leveraging PostCSS Plugins
PostCSS executes plugins via `child_process` modules in `Node.js`. For instance, when processing Tailwind CSS, PostCSS directs the AST to Tailwind's entry point. This entry point allows Tailwind to analyze the AST, specifically targeting the classes utilized within JSX components.
#### The Distinction Between Scripts and Commands
In web development workflows using tools like Vite and PostCSS, it’s crucial to distinguish between scripts and commands:
**Scripts:** Defined within the package.json file under the "scripts" field, scripts are executable commands written in JavaScript. They are run using `npm` or `yarn` commands (`npm run script-name`). Examples include `npm run dev` or `npm run build`, which trigger predefined tasks such as starting a development server or bundling the application for production.
```
// package.json
{
"scripts": {
"dev": "vite",
"build": "vite build"
}
}
```
**Commands:** Commands are direct executable instructions often used in the terminal or command prompt. Unlike scripts in `package.json`, commands like `npx tailwindcss init` is executed directly in the terminal where `init` is actual standalone command of the tailwindcss package which can be executed without any prefix like `npm` locally when installed locally. They perform specific operations associated with the corresponding tool or package without requiring npm or yarn prefixes.
Understanding this distinction is crucial for managing dependencies effectively and optimizing the build process in web development projects.
#### Configuring CSS Bundling with Vite
```
import { defineConfig } from 'vite';
import react from '@vitejs/plugin-react';
export default defineConfig({
plugins: [react()],
css: {
postcss: './postcss.config.js'
}
});
```
The `vite.config.js` file in Vite plays a pivotal role in determining how CSS is bundled and served. Options include:
- **Extract** (`extract` set to true): Bundles CSS separately and includes it in the markup via `<link>` tags, reducing runtime overhead but increasing network requests.
```
// vite.config.js
css: {
devSourcemap: true,
postcss: './postcss.config.js',
preprocessorOptions: {
css: {
extract: true
}
}
}
```
- **Inject** (`inject` set to true): Dynamically injects CSS into the `<head>` of the document during build time using `<style>` tags, reducing network requests but increasing runtime processing.
```
// vite.config.js
css: {
devSourcemap: true,
postcss: './postcss.config.js',
preprocessorOptions: {
css: {
inject: true
}
}
}
```
- **Code Split** (`codeSplit` set to true): Dynamically loads CSS when its corresponding component is rendered, optimizing performance by reducing server and browser overhead.
```
// vite.config.js
css: {
devSourcemap: true,
postcss: './postcss.config.js',
preprocessorOptions: {
css: {
codeSplit: true
}
}
}
```
#### Conclusion
Understanding these processes empowers us developers to optimize CSS bundling effectively using Vite and PostCSS. By integrating these tools, we developers streamline CSS management, enhance application performance, and ensure efficient delivery of styles across different frameworks.
In upcoming articles, we'll delve into JavaScript bundling and provide a comprehensive overview of how applications built on modern frameworks are bundled and shipped. Stay tuned for further insights into optimizing your web development workflow!
| dev_raghvendra |
1,886,222 | Essentials Fear of GOd Hoodies | Essentials Hoodies are your go-to for comfort and style. We have versatile, cozy, and perfect... | 0 | 2024-06-12T21:21:51 | https://dev.to/essentialsclothing11/essentials-fear-of-god-hoodies-53jo | essentails, hoodie, trackcsuit | [Essentials Hoodies](https://essentialsukclothing.com/essentials-hoodie/) are your go-to for comfort and style. We have versatile, cozy, and perfect hoodiess for any occasion. You can upgrade your wardrobe effortlessly with your premium collection. | essentialsclothing11 |
1,886,210 | Seeking for A SKILLED Golang Developer (URGENT HIRING *) | Job Title: Principal Software Engineer (Golang Developer) Location: Fully Remote Job Type:... | 0 | 2024-06-12T21:19:19 | https://dev.to/andrew_king_cd5fbd2e15d08/seeking-for-a-skilled-golang-developer-urgent-hiring--3il4 | go | **Job Title:** Principal Software Engineer (Golang Developer)
**Location:** Fully Remote
**Job Type:** Full-time
**Department:** Engineering/Technology
**Salary:** Negotiable
**Job Summary**
We are in search of a distinguished Principal Software Engineer with a minimum of 15 years of extensive experience in software development, specializing in Golang. The ideal candidate will possess a mastery of modern software engineering practices, a profound understanding of Agile methodologies, and a demonstrated ability to lead and mentor high-performing teams. This role demands exceptional proficiency in API integration, cloud computing, and architectural design.
**Key Responsibilities**
- Architect, design, and implement sophisticated software systems and applications using Golang.
- Lead and drive technical strategy and vision, ensuring alignment with business goals.
- Mentor and provide technical leadership to senior and junior developers, fostering a culture of excellence.
- Conduct in-depth code reviews to maintain the highest standards of code quality.
- Solve complex technical problems and guide the team through technical challenges.
- Optimize and enhance software development processes, leveraging industry best practices.
- Stay ahead of industry trends and emerging technologies to drive continuous innovation.
**Required Qualifications**
- Bachelor’s or Master’s degree in Computer Science, Engineering, or a related field; PhD preferred.
- At least 15 years of hands-on experience in software development with a deep focus on Agile methodologies.
- Extensive experience with Golang and a deep understanding of its paradigms and ecosystem.
- Expertise in API integration and development across diverse platforms, with proven experience in architecting large-scale, distributed systems.
- Extensive experience with cloud platforms including Azure, Google Cloud Platform (GCP), and Amazon Web Services (AWS), with advanced certifications preferred.
- Proficient in CI/CD pipelines, with hands-on experience in implementing and optimizing DevOps practices at an enterprise scale.
- Proven track record of leading and mentoring development teams in high-pressure environments, with at least 5 years of experience in a leadership role.
- Superior verbal and written English communication skills.
- Mastery of NoSQL and SQL databases, with the ability to design, optimize, and manage complex data architectures.
- Exceptional coding skills with a commitment to writing clean, efficient, and maintainable code, evidenced by a portfolio of work or open-source contributions.
- Deep understanding of version control systems, particularly Git, and best practices in code management, including advanced branching and merging strategies.
- Advanced expertise in microservices architecture and system design, with experience in transitioning monolithic systems to microservices.
- Availability for live coding tests and technical assessments as part of the rigorous selection process.
**Preferred Qualifications**
- Experience in leading large-scale, high-impact projects with significant business outcomes.
- Advanced knowledge of containerization and orchestration tools (e.g., Docker, Kubernetes) and serverless architectures, with hands-on experience in deploying and managing large container clusters.
- Proficiency in front-end frameworks and modern web technologies (e.g., React, Angular, Vue.js).
- Comprehensive understanding of security best practices in software development and deployment, with experience in securing complex applications and infrastructure.
- Experience in data science, machine learning, or artificial intelligence applications.
- Published work in reputable journals or conferences in the field of software engineering or related areas.
**Skills**
- Exceptional analytical and problem-solving skills.
- Strong leadership and interpersonal skills with the ability to inspire and motivate teams.
- Excellent organizational and project management abilities.
- Ability to thrive in a fast-paced, dynamic environment.
- Commitment to continuous learning and staying updated with the latest technological advancements.
**How to apply
To apply for the role, please start by submitting your updated resume and a brief 1 or 2-minute introductory video. These materials will give us insight into your experience, qualifications, and interest in the position.**
James King
Contact +1 617 446 3658
**Kindly find attached the LinkedIn profile link of our CTO. I kindly request that you send him a connection request as the initial step in our communication.**
LinkedIn: linkedin.com/in/andrew-king-54926a310 | andrew_king_cd5fbd2e15d08 |
1,886,207 | Exploring Destructuring in JS | Hello, my name is Daniel and I'm a beginner at coding. I am an active student at Flatiron School. In... | 0 | 2024-06-12T21:15:32 | https://dev.to/daniel_trejo14/exploring-destructuring-in-js-114j | Hello, my name is Daniel and I'm a beginner at coding. I am an active student at Flatiron School. In phase-2 we delve heavily into react and all the amazing things it can do. Today I decided to talk about Destructuring a little because it is a super simple yet amazing piece of code. Destructuring allows for a more concise and cleaner code. If I were to have code like this;
```
function EmojiButton(props) {
return (
<button>
<span role="img">{props.emoji}</span>
{props.label}
</button>
)
}
```
If you take a look at the code block, you will see that in some brackets there are some react components that lets us access that information we are grabbing from the `props.emoji` and the `props.label`. Destructuring can be used to clean up some of the the unnecessary words. We can do this a couple ways. One way to do it is doing a const and assigning them as variable that equal the word "props". That will allow us to go without the word props within the components.
```
function EmojiButton(props) {
const { emoji, label } = props
return (
<button>
<span role="img">{emoji}</span>
{label}
</button>
)
}
```
As you can see, it looks a little nicer not having the props all over the place. Now I know it doesn't look like it's doing to much here but I promise when you start coding bigger and longer projects. It will start looking all over the place. Props will be literally everywhere. This way you can see exactly what is it's talking about in a specific piece of code instead of looking through "props" over and over again.
Now, I prefer a different way of desctructuring and it looks like this;
```
function EmojiButton({emoji, label}) {
return (
<button>
<span role="img">{emoji}</span>
{label}
</button>
)
}
```
It does the same thing as the code block before however I really like the fact that it is integrated into the function itself instead of creating a const variable. It looks a lot nicer and cleaner. Now there will be use cases for both and obviously go with whichever one you feel more comfortable with. A lot of coding is preferences with how you want to go about it. Anyway, destructuring is super useful later one when you coding more than a few lines. | daniel_trejo14 | |
1,886,206 | Singleton Design Pattern, TypeScript example | What is Singleton Pattern, use cases and critics. Example of Singleton Pattern in TypeScript. | 0 | 2024-06-12T21:13:07 | https://dev.to/artem/singleton-design-pattern-typescript-example-443e | designpatterns, typescript | ---
title: Singleton Design Pattern, TypeScript example
published: true
description: What is Singleton Pattern, use cases and critics. Example of Singleton Pattern in TypeScript.
tags: #designpatterns #typescript
# cover_image: https://direct_url_to_image.jpg
# Use a ratio of 100:42 for best results.
# published_at: 2024-06-12 19:52 +0000
---
## What is Singleton?
**Context:** Singleton is one of the Creational design patterns
The Singleton Pattern is a design pattern used in programming to ensure that a class has only one instance and provides a global point of access to that instance. This is useful when exactly one object is needed to coordinate actions across a system.
The pattern typically involves:
- Private Constructor: Prevents direct instantiation of the class from outside.
- Static Instance: Holds the single instance of the class.
- Static Method: Provides a way to access the instance, creating it if it doesn't already exist.
This ensures that no matter how many times you request the instance, you always get the same object.
## Good Use Cases for the Singleton Pattern
**1. Configuration Settings:**
Applications often need a single, centralized place to manage configuration settings. A singleton ensures that all parts of the application access the same configuration.
**2. Logging:**
A logging system should be centralized so that all parts of an application write to the same log. Using a singleton ensures that there is only one instance of the logger.
**3. Database Connection:**
Managing a single database connection instance ensures efficient use of resources and avoids the overhead of opening and closing connections repeatedly.
**4. Caching:**
A cache should be globally accessible and consistent across the application. Using a singleton ensures there is a single cache instance.
## Example of Singleton Pattern in TypeScript
Here is the code to implement a simple singleton:
```typescript
class Singleton {
private static instance: Singleton;
private constructor() { }
public static getInstance(): Singleton {
if (!Singleton.instance) {
Singleton.instance = new Singleton();
}
return Singleton.instance;
}
public doAction() {
console.log("action");
}
}
```
Here is how to use this class:
```typescript
const singleton1 = Singleton.getInstance();
const singleton2 = Singleton.getInstance();
// Outputs: true
console.log(singleton1 === singleton2);
// Outputs: 'action'
singleton1.doAction();
```
**Explanation:**
- **Static getInstance Method:** This static method is the key to controlling the access to the Singleton instance. If the instance doesn't already exist, it creates one. If it does exist, it returns the existing instance.
- **Private Constructor:** The constructor is designed to throw an error if it is called directly after the instance is created. This ensures that the Singleton instance is created only through the getInstance method.
- **Instance Variable:** The static property Singleton.instance is used to store the singleton instance. This variable is checked and modified only within the getInstance method.
- **Usage:** When Singleton.getInstance() is called, it either creates a new instance or returns the existing one. Attempting to directly instantiate the class using new Singleton() will throw an error, enforcing the Singleton pattern.
## Criticism, or what are drawbacks of singleton pattern?
**1. Global State.** They are generally used as a global instance, why is that so bad? Because you hide the dependencies of your application in your code, instead of exposing them through the interfaces. It's making the system less transparent.
**2. They violate the single responsibility principle:** by virtue of the fact that they control their own creation and lifecycle.
**3. Can lead to tighter coupling.** Singletons hide dependencies within the class itself, making the system less transparent. This can lead to tighter coupling between classes and reduce modularity. They inherently cause code to be tightly coupled. This makes faking them out under test rather difficult in many cases.
**4. Hard testing.** Singletons can make unit testing more difficult. Since they control their instantiation, it can be hard to substitute them with mock objects or to reset their state between tests, leading to inter-test dependencies.
**5. In multi-threaded applications**, singletons can cause concurrency issues if not implemented correctly, as multiple threads might access and modify the singleton instance simultaneously.
**6. Inflexibility:** Once a singleton is implemented, changing its behavior or replacing it with a different implementation can be difficult. This inflexibility can hinder future development and adaptation.
### Conclusion:
While the Singleton pattern can be useful in specific scenarios where a single instance is truly necessary, it should be used cautiously. Alternatives such as dependency injection can often provide more flexible and testable designs. When considering the Singleton pattern, weigh the pros and cons carefully to determine if it is the best fit for your specific use case.
And here is a meme that perfectly explains my evolution while gather this article :D
---
### Links
- [refactoring.guru | singleton](https://refactoring.guru/design-patterns/singleton)
- [Wikipedia: Singleton Pattern](https://en.wikipedia.org/wiki/Singleton_pattern)
- [What are drawbacks or disadvantages of singleton pattern?](https://stackoverflow.com/questions/137975/what-are-drawbacks-or-disadvantages-of-singleton-pattern)
- [Creational Design Patterns in Golang](https://blog.stackademic.com/creational-design-patterns-b4090683c577) | artem |
1,886,205 | Learn GO: Creating Variables in GO Lang | I just started learning Go and I want myself to be fully committed to it. So, I thought may be should... | 0 | 2024-06-12T20:55:27 | https://dev.to/ivewor/learn-go-creating-variables-in-go-lang-5dim | go, beginners, tutorial, programming | I just started learning Go and I want myself to be fully committed to it. So, I thought may be should start writing about it. It will help me to basically learn each part in some more details and will also help me to track the progress.
I won't be talking about why you should or should not use this language. I just finds this very beautiful and as I always wanted to learn a low level language.
So, let's get started with our first tutorial on how to create variables in GO.
Go is an statically typed language. Basically, we need to assign a the variable type in order to create one like we in other languages such as TypeScript and C++.
For creating a variable in GO the syntax looks like this:
`_var_ variableName type = "value"`
For example, if I have to create a variable of string then I'd do something like this:
`_var_ myVariable string = "hola hola!!"`
However, type is not always necessary as we can also specify the type in value, like this:
`_var_ myVariable = "hola hola!!"`
As strings are in quotes which is used to define strings in a language.
Another version of creating variable is the below one. Which is quite fancy and short, and will probably makes you look like an expert.
`myVariable := "hola hola!"`
This is short declaration of a variable which is pretty useful and great.
Next we can also make creating variables more cooler 😎. By assinging several variables at once. Like this:
`var me, myGF, myWife := "programmer", "programmer", "scientist"`
Now, there are various data types in GO such as string, float, int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64, uintptr, and so on. You read more about [GO Data Types here](https://go.dev/tour/basics/11).
There are other things in GO variables as well. Which I will be talking about in the next post, for now that's it.
If you have questions of suggestions for me to improve do let me know.!! | ivewor |
1,886,203 | Build Your Own Chatbot in Kotlin with GPT: A Step-by-Step Guide | In this post, I'll guide you through a practical example of how to integrate GPT (Generative... | 0 | 2024-06-12T20:47:34 | https://dev.to/josmel/build-your-own-chatbot-in-kotlin-with-gpt-a-step-by-step-guide-27fd | ai, gpt3, kotlin | In this post, I'll guide you through a practical example of how to integrate GPT (Generative Pre-trained Transformer) into a Kotlin application to create a basic chatbot. This chatbot will be able to respond to user queries naturally and efficiently.
### Setting Up the Project
**Step 1: Set Up Dependencies**
First, make sure you have the necessary dependencies in your project. We'll use OkHttp to handle HTTP requests and org.json to work with JSON.
Add the following dependencies to your build.gradle.kts file:
```
dependencies {
implementation("org.jetbrains.kotlin:kotlin-stdlib")
implementation("com.squareup.okhttp3:okhttp:4.9.1")
implementation("org.json:json:20210307")
implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.5.2")
}
```
### Folder structure:
```
ChatbotKotlinGPT/
├── build.gradle.kts
├── gradle/
│ └── wrapper/
│ ├── gradle-wrapper.jar
│ └── gradle-wrapper.properties
├── gradlew
├── gradlew.bat
├── settings.gradle.kts
└── src/
├── main/
│ ├── kotlin/
│ │ ├── Chatbot.kt
│ │ ├── GPTClient.kt
│ │ └── ConversationHandler.kt
│ └── resources/
└── test/
├── kotlin/
└── resources/
```
**Step 2: Configure the GPT Request**
Create a class `GPTClient.kt` to handle requests to the GPT API:
function to send requests to the GPT API and receive responses. You'll need an API key from OpenAI, which you can obtain by signing up on their platform.
```
import okhttp3.*
import okhttp3.MediaType.Companion.toMediaTypeOrNull
import org.json.JSONObject
class GPTClient(private val apiKey: String) {
private val client = OkHttpClient()
fun getResponse(prompt: String): String? {
val requestBody = JSONObject()
.put("model", "gpt-3.5-turbo")
.put("messages", listOf(
mapOf("role" to "user", "content" to prompt)
))
.put("max_tokens", 100)
.toString()
val request = Request.Builder()
.url("https://api.openai.com/v1/chat/completions")
.post(RequestBody.create("application/json".toMediaTypeOrNull(), requestBody))
.addHeader("Authorization", "Bearer $apiKey")
.build()
client.newCall(request).execute().use { response ->
if (!response.isSuccessful) {
println("Error: ${response.code}")
println("Error Body: ${response.body?.string()}")
return null
} else {
val responseBody = response.body?.string()
return JSONObject(responseBody)
.getJSONArray("choices")
.getJSONObject(0)
.getJSONObject("message")
.getString("content")
}
}
}
fun getResponseSafely(prompt: String): String {
return try {
val response = getResponse(prompt)
response ?: "Error: No response from GPT."
} catch (e: Exception) {
"Exception: ${e.message}"
}
}
}
```
**Step 3: Handle Exceptions**
It's important to handle exceptions properly to ensure your application is robust.
```
fun getResponseSafely(prompt: String): String {
return try {
val response = getResponse(prompt)
response ?: "Error: No response from GPT."
} catch (e: Exception) {
"Exception: ${e.message}"
}
}
```
### Using Coroutines for Asynchronous Calls
To improve the efficiency and responsiveness of your application, use Kotlin coroutines to handle GPT API calls asynchronously, Create a class to handle the conversation: `ConversationHandler.kt`, To improve the user experience, you can store the conversation history and provide it to GPT to maintain context.
```
import kotlinx.coroutines.*
class ConversationHandler(private val gptClient: GPTClient) {
private val conversationHistory = mutableListOf<String>()
fun start() = runBlocking {
while (true) {
print("You: ")
val userInput = readLine()
if (userInput.isNullOrEmpty()) break
conversationHistory.add("You: $userInput")
val context = conversationHistory.joinToString("\n")
val gptResponse = async { gptClient.getResponseSafely("Context: $context\nResponse:") }
val response = gptResponse.await()
println("Chatbot: $response")
conversationHistory.add("Chatbot: $response")
}
}
}
```
###Implementing the Chatbot
**Step 1: Create a Simple Interface**
For this example, we'll use a basic console interface to demonstrate interaction with the chatbot. `Chatbot.kt`.
```
fun main() {
val apiKey = "YOUR_API_KEY" // replace with you API_KEY
val gptClient = GPTClient(apiKey)
val conversationHandler = ConversationHandler(gptClient)
conversationHandler.start()
}
```
### Repository
https://github.com/josmel/ChatbotKotlinGPT
### Conclusion
Integrating GPT into a Kotlin application to create a basic chatbot is an excellent way to enhance user interaction. This example provides a solid foundation upon which you can build and add more features as needed. Explore and experiment with these tools to discover their full potential!
| josmel |
1,886,202 | css girl | pure CSS image of a girl with blue eyes and blue hair | 0 | 2024-06-12T20:31:44 | https://dev.to/kemiowoyele1/css-girl-adc | codepen | pure CSS image of a girl with blue eyes and blue hair
{% codepen https://codepen.io/frontend-magic/pen/pojYRjB %} | kemiowoyele1 |
1,609,168 | Building RESTful APIs with Express.js | Welcome to a journey into the world of web architecture! Whether you're a seasoned developer or... | 0 | 2024-06-12T20:29:18 | https://dev.to/labank_/building-restful-apis-with-expressjs-he1 |
Welcome to a journey into the world of web architecture! Whether you're a seasoned developer or just dipping your toes into the vast sea of software development, understanding the core concepts and tools that power the web is essential. In this article, we'll embark on an exploration of two fundamental components that underpin modern web services: REST and Express.js.
## 1. What is REST?
In the realm of web interactions, there exists a crucial architectural style known as REST, which stands for Representational State Transfer. REST is like the conductor of a symphony, bringing harmony and structure to the chaos of web communication between computer systems.
This article is your ticket to exploring the world of RESTful systems, where concepts like statelessness and the segregation of client and server responsibilities reign supreme. But before we dive in, let's demystify REST and understand why it plays such a vital role in the web's infrastructure.
RESTful systems adhere to six fundamental constraints, as initially articulated by Roy Fielding in his doctoral dissertation. These constraints serve as the building blocks of the RESTful style:
- **Uniform Interface:** Creating a common language for both clients and servers.
- **Stateless:** No storage of session information on the server between requests.
- **Cacheable:** Explicitly stating whether responses can be cached.
- **Client-Server:** Keeping client and server concerns separate.
- **Layered System:** Composing systems with multiple layers.
- **Code on Demand:** Providing the option to extend a client's functionality by transferring logic.
REST's appeal lies in its use of HTTP requests for CRUD operations (Create, Read, Update, Delete), making it a straightforward and standardized approach to interact with web services.
## 2. What is Express.js?
Express is a fast, assertive, essential and moderate web framework of Node.js. You can assume express as a layer built on the top of the Node.js that helps manage a server and routes. It provides a robust set of features to develop web and mobile applications.
Let’s see some of the core features of Express framework:
- It can be used to design single-page, multi-page and hybrid web applications.
- It allows to setup middleware to respond to HTTP Requests.
- It defines a routing table which is used to perform different actions based on HTTP method and URL.
- It allows to dynamically render HTML Pages based on passing arguments to templates.
## 3. Express.js Architecture
## 3 Why Choose Express.js?
- Speedy I/O Operations: It handles data quickly.
- Works Smoothly with Asynchronous Tasks: It handles multiple tasks without getting stuck.
- Organized Like MVC: Makes your code neat and organized.
- Easy Routing with a Strong API: Helps you guide your web traffic effortlessly.
## 4 Tools and Tech You Need
- Node.js
- MongoDB
- A Text Editor (like Notepad++, Sublime, Atom, or VSCode)
- Postman (for testing your work)
## What You Need Before We Start
Before we dive in, make sure you have these two essentials installed:
[Node.js](https://nodejs.org/en/download/package-manager)
[MongoDB](https://www.mongodb.com/docs/manual/installation/)
| labank_ | |
1,884,848 | GDSC at Mbeya University of Science and Technology: A Community History | Overview of the GDSC Chapter Introduction to GDSC and Its Mission Google Developer Student... | 0 | 2024-06-12T20:26:22 | https://dev.to/fareedcodez/gdsc-at-mbeya-university-of-science-and-technology-a-community-history-44cd | gdsc, career, community | ## Overview of the GDSC Chapter
**Introduction to GDSC and Its Mission**
Google Developer Student Clubs are university based community groups for students interested in Google developer technologies. Students from all undergraduate or graduate programs with an interest in growing as a developer are welcome. By joining a GDSC, students grow their knowledge in a peer-to-peer learning environment and build solutions for local businesses and their community.
Google Developer Student Clubs (GDSC) aim to empower students to bridge the gap between theory and practice by providing hands-on experiences and fostering a community of learners. Our mission at the [Mbeya University of Science and Technology (MUST)](https://must.ac.tz/) is to inspire and educate students in various tech domains, equipping them with the skills to solve real-world problems and contribute positively to society.
**Formation and Inception**
The [GDSC chapter](https://gdsc.community.dev/mbeya-university-of-science-and-technology-mbeya-tanzania/) at Mbeya University of Science and Technology was founded in 2023, marking a significant milestone in our institution’s journey towards promoting technological innovation and collaboration. Led by [Sitta Ngwesa](https://x.com/fareedcodez), the club began as a small group of tech enthusiasts and quickly grew into a vibrant community committed to learning and development.
**Growth and Development**
Over the year, our chapter grew from a handful of members to a thriving community of over 215 members. We organized numerous events, workshops, and projects that catered to the diverse interests and needs of our members, fostering a culture of learning, innovation, and community engagement.
## Event Highlights
The GDSC community at Mbeya University of Science and Technology has organized numerous impactful events. Here, we highlight some of the most significant ones:
**1. Info Session**
Our introductory [Info Session](https://gdsc.community.dev/events/details/developer-student-clubs-mbeya-university-of-science-and-technology-presents-discover-gdsc/) held on September 15, 2023, served as a welcoming event for new and existing members. We discussed the goals and benefits of being part of GDSC, outlined the year’s planned activities, and introduced our leadership team. This session was crucial for setting the tone for the academic year and encouraging students to actively participate in upcoming events.
**2. Hacktoberfest 2023 in Mbeya**
In collaboration with DigitalOcean, we hosted [Hacktoberfest 2023](https://gdsc.community.dev/events/details/developer-student-clubs-mbeya-university-of-science-and-technology-presents-hacktoberfest-2023-in-mbeya/) in Mbeya on October 28, 2023. This event was part of a global initiative encouraging contributions to open-source projects. Participants learned about open-source development and made their first contributions to various projects, which not only enhanced their coding skills but also fostered a spirit of community and collaboration within the open-source ecosystem.
**3. Exploring the Future of Technology**
Held on March 16, 2024, [Exploring the Future of Technology](https://gdsc.community.dev/events/details/developer-student-clubs-mbeya-university-of-science-and-technology-presents-exploring-the-future-of-technology/) focused on the latest trends and advancements in technology, including artificial intelligence, blockchain, and quantum computing. Guest speakers from leading tech firms provided insights into how these technologies are shaping the future, and students engaged in discussions about their implications and opportunities.
**4. Build with AI**
On April 26, 2024, we conducted the "[Build with AI](https://gdsc.community.dev/events/details/developer-student-clubs-mbeya-university-of-science-and-technology-mbeya-tanzania-presents-build-with-ai/)" workshop, which offered participants hands-on experience with Google’s latest AI tools like Gemini, Vertex AI, and Duet AI. This event aimed to equip students with practical skills in AI/ML and fostered an environment where ideas and projects could be shared and developed collaboratively.
**5. AI/ML Bootcamp: Advanced AI/ML Concepts and Applications**
From May 3-4, 2024, we hosted an intensive [bootcamp ](https://gdsc.community.dev/events/details/developer-student-clubs-mbeya-university-of-science-and-technology-mbeya-tanzania-presents-aiml-bootcamp-introduction-to-aiml-essentials/)on advanced AI and machine learning concepts. Participants were introduced to complex topics such as deep learning, neural networks, and natural language processing. The bootcamp included practical sessions where students built their own AI models using tools like TensorFlow, providing a deep dive into the technical aspects of AI/ML development.
## GDSC Experience
**1. Leadership and Team Dynamics**
As the GDSC Lead, I had the privilege of working with an incredible team of core members who were dedicated to the success of our club. Our teamwork and shared vision were key to overcoming challenges such as organizing events, and these experiences greatly enhanced our leadership and project management skills.
**2. Learning and Skill Development**
Through organizing and participating in various events, our members gained hands-on experience in a range of technologies, including cloud computing, mobile development, and AI, offering members numerous opportunities to learn and apply new technologies. The GDSC platform has been a catalyst for both personal and professional growth, demonstrating the effectiveness of the GDSC model in facilitating career growth.
**3. Community Impact and Legacy**
Our GDSC chapter made a lasting impact at Mbeya University of Science and Technology. Through our events and initiatives, we provided students with valuable opportunities to learn, innovate, and collaborate.
**4. Personal Reflections**
Leading the GDSC chapter at MUST has been one of the most rewarding experiences of my academic career. It has been a journey of growth, learning, and community building. The memories of seeing our members achieve their goals and the impact we made together are ones I will cherish forever. I am confident that the next generation of GDSC leaders will continue to uphold and advance our legacy of innovation and community engagement.
## A Call to Action: Join the GDSC Community and Transform Your Future!
Are you ready to embark on a journey that will shape your future and elevate your skills to new heights? The Google Developer Student Clubs (GDSC) community is the gateway to a world of innovation, learning, and endless opportunities. Here’s why you should pay attention to the GDSC and tech communities and how they can transform your life.
**Why Join the GDSC Community?**
**1. Unleash Your Potential with GDSC**
The GDSC is not just a club; it’s a movement that empowers students to become the tech leaders of tomorrow. Imagine being part of a community where your ideas are nurtured, your skills are honed, and your potential is unleashed. As a member, you gain access to exclusive resources, cutting-edge technology, and a network of like-minded peers who share your passion for innovation.
_"Joining GDSC has been a turning point in my life. The knowledge and connections I've gained are priceless. It’s not just about learning; it’s about growing and leading the way to a brighter future."_
**2. Hands-On Experience with Real Projects**
At GDSC, you’re not just a spectator; you’re a creator. Engage in hands-on projects that address real-world challenges. From AI to mobile development, the projects you work on here will equip you with the skills to tackle the technological demands of the future. Whether it’s building an app, participating in hackathons, or developing AI models, the experience you gain is practical and impactful.
_"The best way to predict the future is to create it."_ – Abraham Lincoln
**3. Network with Industry Leaders**
Becoming a part of GDSC means joining a network of professionals and experts from Google and other leading tech companies. These connections can open doors to internships, jobs, and collaborative projects. The relationships you build here will serve as a foundation for your professional journey.
_"Your network is your net worth."_ – Porter Gale
**4. Develop In-Demand Skills**
The tech industry is ever-evolving, and staying ahead means constantly learning and adapting. GDSC provides workshops and training sessions on the latest technologies, such as cloud computing, machine learning, and mobile app development. The skills you develop here are not only in demand but are also critical for future-proofing your career.
_"Learning never exhausts the mind."_ – Leonardo da Vinci
**5. Make a Difference**
GDSC is not just about personal growth; it’s about making a positive impact. By participating in our Tech for Good initiatives, you can use your skills to solve real-world problems and contribute to the community. Be a part of projects that make a difference and leave a lasting legacy.
_"The best way to find yourself is to lose yourself in the service of others."_ – Mahatma Gandhi
**Why Embrace the Tech Community?**
**1. A World of Opportunities**
The tech industry is booming, and there has never been a better time to dive in. From startups to tech giants, opportunities abound for those with the right skills and a passion for innovation. The tech community is a place where creativity meets opportunity, and every day presents a chance to learn something new and exciting.
_"Technology is best when it brings people together."_ – Matt Mullenweg, Co-founder of WordPress
**2. Be at the Forefront of Innovation**
By joining the tech community, you place yourself at the cutting edge of technology. Be part of the revolution that is shaping the future, whether it’s through AI, blockchain, or IoT. The innovations you work on today will be the foundations of tomorrow’s world.
_"The future belongs to those who believe in the beauty of their dreams."_– Eleanor Roosevelt
**3. Access to a Wealth of Knowledge**
The tech community is rich with knowledge and resources. From online courses and webinars to conferences and meetups, there are endless ways to learn and grow. The community is a melting pot of ideas and experiences, providing a fertile ground for personal and professional development.
_"Knowledge is power. Information is liberating. Education is the premise of progress, in every society, in every family."_– Kofi Annan
**4. Collaborate and Innovate**
One of the greatest benefits of the tech community is the opportunity to collaborate. Work with talented individuals from diverse backgrounds and bring your ideas to life. The collaborative spirit in the tech world fosters creativity and innovation, leading to groundbreaking solutions.
_"Alone we can do so little; together we can do so much."_– Helen Keller
**5. Drive Change**
Technology is a powerful tool for change. By being a part of the tech community, you have the power to create solutions that can address global challenges and improve lives. Whether it’s through coding, design, or strategy, your contributions can make a significant impact.
_"The only way to do great work is to love what you do."_ – Steve Jobs
## Join Us at GDSC and Beyond
At GDSC, we believe in the power of community, learning, and innovation. By joining us, you are taking the first step towards a future filled with possibilities and success. Don’t just witness the change; be a part of it. Embrace the journey, seize the opportunities, and let your passion for technology lead the way.
Be a part of the GDSC at Mbeya University of Science and Technology and embark on a journey of learning, innovation, and impact. Visit our [GDSC community page](https://gdsc.community.dev/mbeya-university-of-science-and-technology-mbeya-tanzania/) for more details on how to join and participate in our events. Your future in tech starts here!
_"The future is not something we enter. The future is something we create."_– Leonard I. Sweet.
| fareedcodez |
1,886,201 | Debugging 101 - How to Fix Software Errors Efficiently | If debugging is the process of removing software bugs, then programming must be the process of... | 0 | 2024-06-12T20:22:48 | https://dev.to/alexindevs/debugging-101-how-to-fix-software-errors-efficiently-5hm2 | webdev, debugging, javascript, programming | > If debugging is the process of removing software bugs, then programming must be the process of putting them in.
You’re sitting at your desk, staring (glaring, rather) at your laptop. It’s 2 am. Your code just isn’t working and you’re not sure why. You’ve tried everything you can think of, but the bug is still there, taunting you. You feel like giving up and going to bed. You feel like throwing your laptop at the wall. You feel like crying. You start to doubt your abilities and wonder if you’ll ever be a great software engineer. In the depths of despair and frustration, you take a deep breath and decide to give it one more shot. You go through your code line by line, trying to find where you went wrong. And then, after what feels like an eternity, you see it.
- A repeated function call.
- A line without proper indentation.
- A dang semicolon.
Bugs are the bane of every developer's existence. They come in all shapes and sizes and can be a real headache to deal with. That’s why in this article, I’ll be teaching you the classic steps to solve any kind of bug in as little time as possible.
## What is a bug?
> A software bug is an error, flaw, or fault in the design, development, or operation of computer software that causes it to produce an incorrect or unexpected result, or to behave in unintended ways. The process of finding and correcting bugs is termed "debugging" and often uses formal techniques or tools to pinpoint bugs. Since the 1950s, some computer systems have been designed to detect or auto-correct various software errors during operations. - Wikipedia
Simply put, a bug is a software error. It’s when your code doesn’t produce the expected results. For example, when you write a function to increment the number 1 till it reaches 10, but you end up with a 10-character string of 1’s instead, that’s a bug. Debugging, on the other hand, is just what it sounds like: removing or fixing bugs.
Now, bugs typically have more disastrous consequences in everyday applications. Imagine a scenario where a bug in a banking application causes a user's balance to be incorrectly displayed or a payment to be processed twice. That could lead to serious financial problems for the user.
## Different types of bugs
Different types of bugs can occur while writing software. Some of the most common types of bugs include:
Syntax errors: Typos, missing punctuation, or incorrect formatting – these basic code mistakes prevent the program from even running.
Logic errors: The code runs smoothly, but the output is wrong due to flaws in the underlying logic, like the banking app example.
Runtime errors: Unexpected situations during execution, like memory issues or accessing invalid data, cause the program to crash or behave erratically.
Misinterpreted requirements: Even with seemingly correct code, the program might not achieve its intended purpose if the developer misunderstood the requirements.
## How to Debug Code
In the following paragraphs, I'll walk you through an efficient bug-solving process step-by-step, using an example to help you understand how to use it effectively.
- Reproduce the error: When you first encounter a bug, you need to reproduce the error to understand its root cause. This involves identifying the specific steps or conditions that trigger the issue and then attempting to replicate them in a non-production environment.
- Isolate the bug: To identify faulty code, the error message needs to be examined meticulously and then traced back to the specific line or lines of code that caused the issue. This may involve debugging tools, print statements, or code reviews.
- Understand the Code: Go through every line of code in the program. Make sure you comprehend what each line is supposed to do.
- Test Inputs and Outputs: Test your code with different inputs to see if the bug occurs consistently or only under certain conditions.
- Fix the bug: At this point, you’ve probably identified the error in your code. Check for syntax errors, faulty logic, and issues with external dependencies. Brainstorm the solution to the bug, then refine it.
- Do research: If you can’t come up with a solution on your own, it’s best to do some research online. Debug with your favorite AI tool. Look for forums like Stack Overflow where people may have experienced a similar issue and have found a solution. You can also search for tutorials or guides on how to fix the problem. If no solution is found, reach out to colleagues and senior engineers for assistance.
- Test your solution: Once you have found a solution, test it. Make sure that the bug is completely fixed and that it doesn't cause any new issues or side effects. It's always a good idea to get a second opinion from a colleague or mentor before deploying the code to a production environment.
In conclusion, debugging is an essential skill for any developer. It can be a frustrating and time-consuming process, but with the right approach, it doesn't have to be. By following the steps outlined in this article, you can systematically identify and fix bugs in your code, saving yourself countless hours of hair-pulling and frustration. Remember, bugs are inevitable, but with practice and patience, you can become a proficient debugger. Thanks for reading! | alexindevs |
1,873,358 | Advanced JavaScript | Introduction JavaScript has evolved significantly since its inception, becoming one of the... | 27,559 | 2024-06-12T20:21:00 | https://dev.to/suhaspalani/advanced-javascript-f4l | webdev, javascript, programming, beginners | #### Introduction
JavaScript has evolved significantly since its inception, becoming one of the most powerful and flexible programming languages for web development. Understanding advanced JavaScript concepts is crucial for building complex and efficient applications. This week, we'll dive into some of these advanced topics, including closures, promises, async/await, ES6 modules, and design patterns.
#### Importance of Advanced JavaScript Concepts
Advanced JavaScript concepts allow developers to write more efficient, maintainable, and scalable code. Mastering these topics is essential for tackling complex real-world applications and enhancing your problem-solving skills.
#### Closures
**Understanding Closures:**
- **Definition**: A closure is a function that retains access to its lexical scope even when the function is executed outside that scope.
- **Why Use Closures?**: Closures are useful for data privacy, creating function factories, and maintaining state between function calls.
**Practical Examples of Closures:**
- **Example 1**: Basic Closure
```javascript
function outerFunction() {
let outerVariable = 'I am outside!';
function innerFunction() {
console.log(outerVariable);
}
return innerFunction;
}
const closureExample = outerFunction();
closureExample(); // Output: 'I am outside!'
```
- **Example 2**: Data Privacy
```javascript
function createCounter() {
let count = 0;
return function() {
count++;
return count;
}
}
const counter = createCounter();
console.log(counter()); // Output: 1
console.log(counter()); // Output: 2
```
#### Promises
**Introduction to Promises:**
- **Definition**: A promise is an object representing the eventual completion (or failure) of an asynchronous operation and its resulting value.
- **Why Use Promises?**: Promises simplify handling asynchronous operations, making code easier to read and maintain.
**Creating and Using Promises:**
- **Creating a Promise**:
```javascript
const myPromise = new Promise((resolve, reject) => {
// Asynchronous operation
setTimeout(() => {
resolve('Promise resolved!');
}, 2000);
});
```
- **Using a Promise**:
```javascript
myPromise.then((value) => {
console.log(value); // Output: 'Promise resolved!'
}).catch((error) => {
console.error(error);
});
```
**Handling Asynchronous Operations with Promises:**
- **Example**: Fetching Data
```javascript
fetch('https://api.example.com/data')
.then(response => response.json())
.then(data => console.log(data))
.catch(error => console.error('Error:', error));
```
#### Async/Await
**Introduction to Async/Await:**
- **Definition**: `async` and `await` are syntactic sugar built on promises, allowing for more readable and synchronous-looking asynchronous code.
- **Why Use Async/Await?**: Simplifies writing and reading asynchronous code by avoiding chaining multiple `then` calls.
**Converting Promises to Async/Await:**
- **Example**:
```javascript
async function fetchData() {
try {
const response = await fetch('https://api.example.com/data');
const data = await response.json();
console.log(data);
} catch (error) {
console.error('Error:', error);
}
}
fetchData();
```
**Error Handling with Async/Await:**
- **Example**:
```javascript
async function getData() {
try {
let response = await fetch('https://api.example.com/data');
let data = await response.json();
console.log(data);
} catch (error) {
console.error('Fetch error:', error);
}
}
getData();
```
#### JavaScript Modules
**ES6 Modules:**
- **Introduction**: ES6 introduced a standardized module system for JavaScript.
- **Why Use Modules?**: Modules help organize code, make it reusable, and avoid naming conflicts.
**Importing and Exporting Modules:**
- **Exporting**:
```javascript
// math.js
export function add(a, b) {
return a + b;
}
export const PI = 3.14;
```
- **Importing**:
```javascript
// main.js
import { add, PI } from './math.js';
console.log(add(2, 3)); // Output: 5
console.log(PI); // Output: 3.14
```
#### JavaScript Design Patterns
**Common Design Patterns in JavaScript:**
- **Singleton Pattern**: Ensures a class has only one instance and provides a global point of access to it.
- **Module Pattern**: Encapsulates private variables and functions using closures and exposes public APIs.
- **Observer Pattern**: Defines a subscription mechanism to notify multiple objects about state changes.
**Practical Examples:**
- **Singleton Pattern**:
```javascript
const Singleton = (function() {
let instance;
function createInstance() {
return new Object('I am the instance');
}
return {
getInstance: function() {
if (!instance) {
instance = createInstance();
}
return instance;
}
};
})();
const instance1 = Singleton.getInstance();
const instance2 = Singleton.getInstance();
console.log(instance1 === instance2); // Output: true
```
- **Module Pattern**:
```javascript
const Module = (function() {
let privateVariable = 'I am private';
function privateMethod() {
console.log(privateVariable);
}
return {
publicMethod: function() {
privateMethod();
}
};
})();
Module.publicMethod(); // Output: 'I am private'
```
#### Conclusion
Mastering advanced JavaScript concepts is essential for building complex applications efficiently and effectively. These concepts allow you to write more maintainable and robust code, ultimately making you a better developer.
#### Resources for Further Learning
- **Online Courses**: Websites like Udemy, Pluralsight, and freeCodeCamp offer courses on advanced JavaScript topics.
- **Books**: "JavaScript: The Definitive Guide" by David Flanagan, "You Don't Know JS" series by Kyle Simpson.
- **Documentation and References**: MDN Web Docs (Mozilla Developer Network) provides comprehensive documentation and examples for advanced JavaScript concepts.
- **Communities**: Join developer communities on platforms like Stack Overflow, Reddit, and GitHub for support and networking.
| suhaspalani |
1,886,188 | L1SLOAD el nuevo opcode para Keystores seguras y escalables | Las funciones de abstracción de cuentas cross-chain serán posibles gracias a los Keystores. Los... | 0 | 2024-06-12T20:18:56 | https://dev.to/turupawn/l1sload-el-nuevo-opcode-para-keystores-seguras-y-escalables-50of | ---
title: L1SLOAD el nuevo opcode para Keystores seguras y escalables
published: true
description:
tags:
# cover_image: https://direct_url_to_image.jpg
# Use a ratio of 100:42 for best results.
# published_at: 2024-06-06 15:00 +0000
---
Las funciones de abstracción de cuentas cross-chain serán posibles gracias a los [Keystores](https://notes.ethereum.org/@vbuterin/minimal_keystore_rollup). Los usuarios podrán controlar varias smart contracts wallets, en múltiples chains, con una sola llave. Esto puede traer la tan esperada buena experiencia de usuario para los usuarios finales en [los rollups de Ethereum](https://ethereum-magicians.org/t/a-rollup-centric-ethereum-roadmap/4698).
Para que esto suceda, necesitamos poder leer los datos de L1 desde los rollups en L2, lo cual actualmente es un proceso muy costoso. Es por eso que Scroll introdujo recientemente el precompile `L1SLOAD` que es capaz de leer el estado de L1 de manera rápida y económica. Safe wallet ha creado un demo presentado en Safecon Berlín 2024. Pienso que esto es solo el comienzo, esto podrá mejorar aplicaciones cross-chain en DeFi, juegos, redes sociales y muchos más.
Vamos ahora a aprender, con ejemplos prácticos, los conceptos básicos de esta nueva primitiva que está abre la puerta a una nueva forma de interactuar con Ethereum.
## 1. Conecta tu wallet al Scroll Devnet
Actualmente, `L1SLOAD` está disponible únicamente en la Scroll Devnet. Toma nota y no la confundas con la Scroll Sepolia Testnet. Aunque ambos están desplegados sobre el Sepolia Testnet, son cadenas separadas.
Comenzamos conectando nuestra wallet a la Scroll Devnet:
* Name: `Scroll Devnet`
* RPC: `https://l1sload-rpc.scroll.io`
* Chain id: `222222`
* Symbol: `Sepolia ETH`
* Explorer: `https://l1sload-blockscout.scroll.io`
## 2. Obtener fondos en Scroll Devnet
Existen dos métodos de obtener fondos en la Scroll Devnet. Elige el que prefieras.
{% collapsible Bot de Faucet en Telegram (recomendado) %}
Únete a [este grupo de telegram](https://t.me/scroll_l1sload_devnet_bot) y escribe `/drop TUADDRESS` (e.g. `/drop 0xd8da6bf26964af9d7eed9e03e53415d37aa96045`) para recibir fondos directo a tu cuenta.
{% endcollapsible %}
{% collapsible Bridge de Sepolia %}
Puedes enviar fondos de Sepolia a la Scroll Devnet a través del bridge. Existen dos maneras de lograr esto pero en este caso usaremos Remix.
Conectemos ahora tu wallet con Sepolia ETH a Sepolia Testnet. Recuerda que puedes obtener Sepolia ETH grátis en [un faucet](https://sepoliafaucet.com/),
Ahora compila la siguiente interfaz.
```js
// SPDX-License-Identifier: MIT
pragma solidity >=0.7.0 <0.9.0;
interface ScrollMessanger {
function sendMessage(address to, uint value, bytes memory message, uint gasLimit) external payable;
}
```
A continuación, en la tab de "Deploy & Run" conecta el contrato siguiente: `0x561894a813b7632B9880BB127199750e93aD2cd5`.
Ahora puedes enviar ETH llamando la función `sendMessage` como se detalla a continación:
* to: La dirección de tu cuenta EOA. El address que recibirá fondos en L2.
* value: La cantidad de ether que deseas recibir en L2, en formato wei. Por ejemplo, si envías `0.01` ETH debes pasar como parámetro `10000000000000000`
* message: Déjalo en blanco, simplemente envía `0x00`
* gasLimit: `1000000` debería ser suficiente
Also remember to pass some value to your transaction. And add some extra ETH to pay for fees on L2, `0.001` should be more than enough. So if for example you sent `0.01` ETH on the bridge, send a transaction with `0.011` ETH to cover the fees.
También recuerda pasar un extra `value` en tu transacción. Es decir, agrega un poco de ETH extra para pagar las comisiones en L2, `0.001` debería ser más que suficiente. Así que, por ejemplo, si enviaste 0.01 ETH en el bridge, envía una transacción con `0.011` ETH para cubrir las comisiones.
{% endcollapsible %}
Haz click en el botón `transact` y tus fondos deberían llegar en 15 mins aproximadamente.
## 2. Lanza tu contrato en L2
Tal y como mencionamos anteriormente, `L1SLOAD` lee el estado de contratos en L1 desde L2. Lancemos ahora un contrato simple en L1 que luego leeremos el valor de la variable `number` desde L2.
```js
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.20;
/**
* @title Storage
* @dev Store & retrieve value in a variable
*/
contract L1Storage {
uint256 public number;
/**
* @dev Store value in variable
* @param num value to store
*/
function store(uint256 num) public {
number = num;
}
/**
* @dev Return value
* @return value of 'number'
*/
function retrieve() public view returns (uint256){
return number;
}
}
```
Ahora llamamos `store(uint256 num)` pasándole un nuevo valor para la variable `number`. Por ejemplo, le podemos pasar `42`.
## 3. Obtener una slot desde L2
Lanzamos el siguiente contrato en L2 pasando el address del contrato que recién lanzamos en L1 como parámetro en el constructor.
```js
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.20;
interface IL1Blocks {
function latestBlockNumber() external view returns (uint256);
}
contract L2Storage {
address constant L1_BLOCKS_ADDRESS = 0x5300000000000000000000000000000000000001;
address constant L1_SLOAD_ADDRESS = 0x0000000000000000000000000000000000000101;
uint256 constant NUMBER_SLOT = 0;
address immutable l1StorageAddr;
uint public l1Number;
constructor(address _l1Storage) {
l1StorageAddr = _l1Storage;
}
function latestL1BlockNumber() public view returns (uint256) {
uint256 l1BlockNum = IL1Blocks(L1_BLOCKS_ADDRESS).latestBlockNumber();
return l1BlockNum;
}
function retrieveFromL1() public {
uint256 l1BlockNum = IL1Blocks(L1_BLOCKS_ADDRESS).latestBlockNumber();
bytes memory input = abi.encodePacked(l1BlockNum, l1StorageAddr, NUMBER_SLOT);
bool success;
bytes memory ret;
(success, ret) = L1_SLOAD_ADDRESS.call(input);
if (success) {
(l1Number) = abi.decode(ret, (uint256));
} else {
revert("L1SLOAD failed");
}
}
}
```
Observa que este contrato primero llama `latestL1BlockNumber()` para obtener el más reciente bloque en L1 que está disponible para lectura en L2. Luego, llamamos `L1SLOAD` (opcode `0x101`) pasando el address del contrato en L1 como parámetro y la slot 9 que es donde la variable `number` está ubicada dentro de ese contrato.
Ahora podemos llamar `retrieveFromL1()` para obtener el valor almacenado previamente.
## Ejemplo #2: Leer otros tipos de variables
Solidity guarda las slots de las variables en el mismo orden en la que fueron declaradas. Esto es bastante conveniente para nosotros. Por ejemplo, en el siguiente contrato, `account` se almacena en la slot #0, `number` en la #1 y `text` en la #2.
```js
// SPDX-License-Identifier: MIT
pragma solidity >=0.7.0 <0.9.0;
contract AdvancedL1Storage {
address public account;
uint public number;
string public text;
}
```
Podemos observar que cómo podemos obtener los valores de diferentes tipos: uint256, address, etc... Las strings son un poco diferente por la naturaleza variable de su tamaño.
```js
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.20;
interface IL1Blocks {
function latestBlockNumber() external view returns (uint256);
}
contract L2Storage {
address constant L1_BLOCKS_ADDRESS = 0x5300000000000000000000000000000000000001;
address constant L1_SLOAD_ADDRESS = 0x0000000000000000000000000000000000000101;
address immutable l1ContractAddress;
address public account;
uint public number;
string public test;
constructor(address _l1ContractAddress) { //0x5555158Ea3aB5537Aa0012AdB93B055584355aF3
l1ContractAddress = _l1ContractAddress;
}
// Internal functions
function latestL1BlockNumber() internal view returns (uint256) {
uint256 l1BlockNum = IL1Blocks(L1_BLOCKS_ADDRESS).latestBlockNumber();
return l1BlockNum;
}
function retrieveSlotFromL1(uint blockNumber, address l1StorageAddress, uint slot) internal returns (bytes memory) {
bool success;
bytes memory returnValue;
(success, returnValue) = L1_SLOAD_ADDRESS.call(abi.encodePacked(blockNumber, l1StorageAddress, slot));
if(!success)
{
revert("L1SLOAD failed");
}
return returnValue;
}
function decodeStringSlot(bytes memory encodedString) internal pure returns (string memory) {
uint length = 0;
while (length < encodedString.length && encodedString[length] != 0x00) {
length++;
}
bytes memory data = new bytes(length);
for (uint i = 0; i < length; i++) {
data[i] = encodedString[i];
}
return string(data);
}
// Public functions
function retrieveAddress() public {
uint256 l1BlockNum = IL1Blocks(L1_BLOCKS_ADDRESS).latestBlockNumber();
account = abi.decode(retrieveSlotFromL1(l1BlockNum, l1ContractAddress, 0), (address));
}
function retrieveNumber() public {
uint256 l1BlockNum = IL1Blocks(L1_BLOCKS_ADDRESS).latestBlockNumber();
number = abi.decode(retrieveSlotFromL1(l1BlockNum, l1ContractAddress, 1), (uint));
}
function retrieveString() public {
uint256 l1BlockNum = IL1Blocks(L1_BLOCKS_ADDRESS).latestBlockNumber();
test = decodeStringSlot(retrieveSlotFromL1(l1BlockNum, l1ContractAddress, 2));
}
function retrieveAll() public {
uint256 l1BlockNum = IL1Blocks(L1_BLOCKS_ADDRESS).latestBlockNumber();
account = abi.decode(retrieveSlotFromL1(l1BlockNum, l1ContractAddress, 0), (address));
number = abi.decode(retrieveSlotFromL1(l1BlockNum, l1ContractAddress, 1), (uint));
test = decodeStringSlot(retrieveSlotFromL1(l1BlockNum, l1ContractAddress, 2));
}
}
```
## Ejemplo #3: Leer el balance de un token ERC20 en L1
Comenzamos lanzando un token ERC20 bastante sencillo.
```js
// SPDX-License-Identifier: MIT
pragma solidity 0.8.17;
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
contract SimpleToken is ERC20 {
constructor(
string memory name,
string memory symbol,
uint256 initialSupply
) ERC20(name, symbol) {
_mint(msg.sender, initialSupply * 1 ether);
}
}
```
A continuación, lanzamos el siguiente contrato en L2 pasando como parámetros el address del token que recién lanzamos en L1.
```js
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.20;
interface IL1Blocks {
function latestBlockNumber() external view returns (uint256);
}
contract L2Storage {
address constant L1_BLOCKS_ADDRESS = 0x5300000000000000000000000000000000000001;
address constant L1_SLOAD_ADDRESS = 0x0000000000000000000000000000000000000101;
address immutable l1ContractAddress;
uint public l1Balance;
constructor(address _l1ContractAddress) {
l1ContractAddress = _l1ContractAddress;
}
// Internal functions
function latestL1BlockNumber() public view returns (uint256) {
uint256 l1BlockNum = IL1Blocks(L1_BLOCKS_ADDRESS).latestBlockNumber();
return l1BlockNum;
}
function retrieveSlotFromL1(uint blockNumber, address l1StorageAddress, uint slot) internal returns (bytes memory) {
bool success;
bytes memory returnValue;
(success, returnValue) = L1_SLOAD_ADDRESS.call(abi.encodePacked(blockNumber, l1StorageAddress, slot));
if(!success)
{
revert("L1SLOAD failed");
}
return returnValue;
}
// Public functions
function retrieveL1Balance(address account) public {
uint slotNumber = 0;
uint256 l1BlockNum = IL1Blocks(L1_BLOCKS_ADDRESS).latestBlockNumber();
l1Balance = abi.decode(retrieveSlotFromL1(
l1BlockNum,
l1ContractAddress,
uint(keccak256(
abi.encodePacked(uint160(account),slotNumber)
)
)
), (uint));
}
}
```
Los contratos de OpenZeppelin colocan convenientemente el mapping de [los balances del token en el Slot 0](https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/ERC20.sol#L30). Así que puedes llamar a `retrieveL1Balance()` pasando el address del holder como parámetro y el balance del token se almacenará en la variable `l1Balance`. Como puedes ver en el código, el proceso es primer convertir el address a uint160 y luego lo hasheamos con el slot del mapping, que es 0. Esto se debe a que es así como Solidity implementa los mappings.
**¡Gracias por leer esta guía!**
Sígueme en dev.to y en [Youtube](https://www.youtube.com/channel/UCNRB4tgwp09z4391JRjEsRA) para todo lo relacionado al desarrollo en Blockchain en Español. | turupawn | |
1,879,464 | How to use L1SLOAD, the Keystore backbone | Seamless cross-chain account abstraction features will be possible thanks to Keystores. Were users... | 0 | 2024-06-12T20:18:44 | https://dev.to/filosofiacodigoen/how-to-use-l1sload-the-keystores-backbone-25ah | ---
title: How to use L1SLOAD, the Keystore backbone
published: true
description:
tags:
# cover_image: https://direct_url_to_image.jpg
# Use a ratio of 100:42 for best results.
# published_at: 2024-06-06 15:00 +0000
---
Seamless cross-chain account abstraction features will be possible thanks to [Keystores](https://notes.ethereum.org/@vbuterin/minimal_keystore_rollup). Were users will be able to control multiple smart contract accounts, on multiple chains, with a single key. This will bring rollups closer and provide the so long waited good UX for end users in a [rollup centric Ethereum](https://ethereum-magicians.org/t/a-rollup-centric-ethereum-roadmap/4698).
In order to make this happen, we need to be able to read the L1 data from L2 rollups which is currently a very expensive process. That's why Scroll [recently introduced](https://scroll.io/blog/towards-the-wallet-endgame-with-keystore) the `L1SLOAD` precompile that is able to read the L1 State fast and cheap. Safe wallet is already creating [a proof of concept](https://github.com/5afe/safe-scroll-keystore) [introduced at Safecon Berlin 2024](https://www.youtube.com/watch?v=hHmOo7A3vNU) of this work and I think this is just the begining: DeFi, gamming, social and many more types of corss-chain applications are possible with this.
Let's now learn, with examples, the basics of this new primitive that is set to open the door to a new way of interacting with Ethereum.
## 1. Connect your wallet to the devnet
Currently, `L1SLOAD` is available only on the Scroll Devnet. Please don't confuse it with the Scroll Sepolia Testnet. Although both are deployed on top of Sepolia Testnet, they are separate chains.
Let's start by connecting our wallet to Scroll Devnet:
* Name: `Scroll Devnet`
* RPC: `https://l1sload-rpc.scroll.io`
* Chain id: `2227728`
* Symbol: `Sepolia ETH`
* Explorer: `https://l1sload-blockscout.scroll.io`
## 2. Get some funds on the L2 devnet
There are two methods for obtaining funds on the Scroll Devnet. Choose whichever option you prefer.
{% collapsible Telegram faucet bot (recommended) %}
Join [this telegram group](https://t.me/scroll_l1sload_devnet_bot) and type `/drop YOURADDRESS` (e.g. `/drop 0xd8da6bf26964af9d7eed9e03e53415d37aa96045`) to receive funds directly to your account.
{% endcollapsible %}
{% collapsible Sepolia Bridge %}
You can bridge Sepolia ETH from Sepolia Testnet to Sepolia Devnet through the Scroll Messenger. There are different ways of achieving this but in this case we're going to use Remix.
Let's start by connecting your wallet with Sepolia ETH to Sepolia Testnet. Remember you can get some Sepolia ETH for free [from a faucet](https://sepoliafaucet.com/).
Now compile the following interface.
```js
// SPDX-License-Identifier: MIT
pragma solidity >=0.7.0 <0.9.0;
interface ScrollMessanger {
function sendMessage(address to, uint value, bytes memory message, uint gasLimit) external payable;
}
```
Next, on the Deploy & Run tab connect the following contract address: `0x9810147b43D7Fa7B9a480c8867906391744071b3`.
You can now send ETH by calling the `sendMessage` function. As explained below:
* to: Your EOA wallet address. The the ETH recipient on L2
* value: The amount you wish to receive on L2 in wei. For example, if you want to send `0.01` ETH you should pass `10000000000000000`
* message: Leave this empty, just pass `0x00`
* gasLimit: `1000000` should be fine
Also remember to pass some value to your transaction. And add some extra ETH to pay for fees on L2, `0.001` should be more than enough. So if for example you sent `0.01` ETH on the bridge, send a transaction with `0.011` ETH to cover the fees.
Click the transact button and your funds should be available in around 15 mins.
{% endcollapsible %}
## 2. Deploy a contract on L1
As mentioned earlier, `L1SLOAD` reads L1 contract state from L2. Let's deploy a simple L1 contract with a `number` variable and later access it from L2.
```js
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.20;
/**
* @title Storage
* @dev Store & retrieve value in a variable
*/
contract L1Storage {
uint256 public number;
/**
* @dev Store value in variable
* @param num value to store
*/
function store(uint256 num) public {
number = num;
}
/**
* @dev Return value
* @return value of 'number'
*/
function retrieve() public view returns (uint256){
return number;
}
}
```
Now call the `store(uint256 num)` function and pass a new value. For example let's pass `42`.
## 3. Retrieve a Slot from L2
Now let's deploy the following contract on L2 by passing the L1 contract address we just deployed as constructor param.
```js
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.20;
interface IL1Blocks {
function latestBlockNumber() external view returns (uint256);
}
contract L2Storage {
address constant L1_BLOCKS_ADDRESS = 0x5300000000000000000000000000000000000001;
address constant L1_SLOAD_ADDRESS = 0x0000000000000000000000000000000000000101;
uint256 constant NUMBER_SLOT = 0;
address immutable l1StorageAddr;
constructor(address _l1Storage) {
l1StorageAddr = _l1Storage;
}
function latestL1BlockNumber() public view returns (uint256) {
uint256 l1BlockNum = IL1Blocks(L1_BLOCKS_ADDRESS).latestBlockNumber();
return l1BlockNum;
}
function retrieveFromL1() public view returns(uint) {
bytes memory input = abi.encodePacked(l1StorageAddr, NUMBER_SLOT);
bool success;
bytes memory ret;
(success, ret) = L1_SLOAD_ADDRESS.staticcall(input);
if (!success) {
revert("L1SLOAD failed");
}
return abi.decode(ret, (uint256));
}
}
```
Notice this contract first calls `latestL1BlockNumber()` to get the latest L1 block that L2 has visibility on. And then calls `L1SLOAD` (opcode `0x101`) by passing the L1 contract address and the slot 0 where the `uint number` is stored.
Now we can call `retrieveFromL1()` to get the value we previously stored.
## Example #2: Reading other variable types
Luckily for us, Solidity stores the slots in the same order as they were declared. For example, in the following contract `account` will be stored on slot #0, `number` slot #1 and `text` on slot #2.
```js
// SPDX-License-Identifier: MIT
pragma solidity >=0.7.0 <0.9.0;
contract AdvancedL1Storage {
address public account = msg.sender;
uint public number = 42;
string public str = "Hello world!";
}
```
So, you can notice on the following example how you can query the different slots and decode accordingly to uint256, address, etc... The only different native type that needs special decoding is the `string` type.
```js
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.20;
contract L2Storage {
address constant L1_BLOCKS_ADDRESS = 0x5300000000000000000000000000000000000001;
address constant L1_SLOAD_ADDRESS = 0x0000000000000000000000000000000000000101;
address immutable l1ContractAddress;
constructor(address _l1ContractAddress) {
l1ContractAddress = _l1ContractAddress;
}
// Internal functions
function bytes32ToString(bytes32 _bytes32) public pure returns (string memory) {
bytes memory bytesArray = new bytes(32);
for (uint256 i; i < 32; i++) {
if(_bytes32[i] == 0x00)
break;
bytesArray[i] = _bytes32[i];
}
return string(bytesArray);
}
// Public functions
function retrieveAll() public view returns(address, uint, string memory) {
bool success;
bytes memory data;
uint[] memory l1Slots = new uint[](3);
l1Slots[0] = 0;
l1Slots[1] = 1;
l1Slots[2] = 2;
(success, data) = L1_SLOAD_ADDRESS.staticcall(abi.encodePacked(l1ContractAddress, l1Slots));
if(!success)
{
revert("L1SLOAD failed");
}
address l1Account;
uint l1Number;
bytes32 l1Str;
assembly {
let temp := 0x20
// Load the data into memory
let ptr := add(data, 32) // Start at the beginning of data skipping the length field
// Store the first slot from L1 into the account variable
mstore(temp, mload(ptr))
l1Account := mload(temp)
ptr := add(ptr, 32)
// Store the second slot from L1 into the number variable
mstore(temp, mload(ptr))
l1Number := mload(temp)
ptr := add(ptr, 32)
// Store the third slot from L1 into the str variable
mstore(temp, mload(ptr))
l1Str := mload(temp)
}
return (l1Account, l1Number, bytes32ToString(l1Str));
}
}
```
## Example #3: Reading ERC20 token balance from L1
Let's start by deploying the following very simple ERC20 token.
```js
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.17;
import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
contract SimpleToken is ERC20 {
constructor() ERC20("Simple Token", "STKN") {
_mint(msg.sender, 21_000_000 ether);
}
}
```
Next, we can deploy the following contract on L2 by passing the L1 token address as parameter.
```js
// SPDX-License-Identifier: GPL-3.0
pragma solidity ^0.8.20;
interface IL1Blocks {
function latestBlockNumber() external view returns (uint256);
}
contract L2Storage {
address constant L1_BLOCKS_ADDRESS = 0x5300000000000000000000000000000000000001;
address constant L1_SLOAD_ADDRESS = 0x0000000000000000000000000000000000000101;
address immutable l1TokenAddress;
constructor(address _l1TokenAddress) {
l1TokenAddress = _l1TokenAddress;
}
// Internal functions
function retrieveSlotFromL1(address l1StorageAddress, uint slot) internal view returns (bytes memory) {
bool success;
bytes memory returnValue;
(success, returnValue) = L1_SLOAD_ADDRESS.staticcall(abi.encodePacked(l1StorageAddress, slot));
if(!success)
{
revert("L1SLOAD failed");
}
return returnValue;
}
// Public functions
function retrieveL1Balance(address account) public view returns(uint) {
uint slotNumber = 0;
return abi.decode(retrieveSlotFromL1(
l1TokenAddress,
uint(keccak256(
abi.encodePacked(uint(uint160(account)),slotNumber)
)
)
), (uint));
}
}
```
OpenZeppelin contracts conveniently places [the balances mapping on Slot 0](https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/token/ERC20/ERC20.sol#L30). So you can call `retrieveL1Balance()` by passing the account address as paramater and the token balance will be stored on the `l1Balance` variable. As you can see on the code, it works by converting the account to `uint160` and then hashing it with the mapping slot which is 0. This is because that's the way the Solidity implemented mappings.
**Thanks for reading this guide!**
Follow Filosofía Código on dev.to and in [Youtube]( https://www.youtube.com/channel/UCbF5CFuXv2vTkcGfepWV2nA) for everything related to Blockchain development. | turupawn | |
1,886,189 | Estudos em Quality Assurance (QA) - Como Reportar um Bug | Título: Um título claro e conciso que descreve o problema de forma sucinta. Prioridade: Classifique... | 0 | 2024-06-12T20:14:32 | https://dev.to/julianoquites/estudos-em-quality-assurance-qa-como-reportar-um-bug-2f69 | qa, testing, learning, testedesoftware | **Título:** Um título claro e conciso que descreve o problema de forma sucinta.
**Prioridade:** Classifique a prioridade do bug de acordo com sua gravidade, usando escalas como P0 (crítico) a P3 (menos crítico).
**Resumo:** Uma breve descrição do bug, incluindo informações adicionais relevantes.
**Passos para Reproduzir:** Liste os passos específicos necessários para reproduzir o bug, tornando-os claros e concisos.
**Resultados Esperados:** Descreva o que deveria acontecer de acordo com os critérios de aceitação definidos no documento de requisitos de negócios (BRD).
**Resultados Atuais:** Descreva o que realmente aconteceu quando os passos foram seguidos, destacando o problema encontrado.
**Ambiente:** Especifique o sistema e as condições sob as quais o problema ocorreu, incluindo detalhes como sistema operacional, navegador, versão do software, etc.
**Logs e Evidências:** Anexe qualquer log relevante, capturas de tela, vídeos ou outros tipos de evidências que possam ajudar na compreensão e resolução do bug.
Qual ferramenta escolher?
Uma das ferramentas mais populares entre equipes de desenvolvimento é a **Jira**, devido à sua flexibilidade, recursos avançados de rastreamento de problemas e integração com outros sistemas de desenvolvimento.
| julianoquites |
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