| Foreword |
| ======== |
|
|
| Read this before you get started with Flask. This hopefully answers some |
| questions about the purpose and goals of the project, and when you |
| should or should not be using it. |
|
|
| What does "micro" mean? |
| |
|
|
| “Micro” does not mean that your whole web application has to fit into a single |
| Python file (although it certainly can), nor does it mean that Flask is lacking |
| in functionality. The "micro" in microframework means Flask aims to keep the |
| core simple but extensible. Flask won't make many decisions for you, such as |
| what database to use. Those decisions that it does make, such as what |
| templating engine to use, are easy to change. Everything else is up to you, so |
| that Flask can be everything you need and nothing you don't. |
|
|
| By default, Flask does not include a database abstraction layer, form |
| validation or anything else where different libraries already exist that can |
| handle that. Instead, Flask supports extensions to add such functionality to |
| your application as if it was implemented in Flask itself. Numerous extensions |
| provide database integration, form validation, upload handling, various open |
| authentication technologies, and more. Flask may be "micro", but it's ready for |
| production use on a variety of needs. |
|
|
| Configuration and Conventions |
| |
|
|
| Flask has many configuration values, with sensible defaults, and a few |
| conventions when getting started. By convention, templates and static |
| files are stored in subdirectories within the application's Python |
| source tree, with the names :file:`templates` and :file:`static` |
| respectively. While this can be changed, you usually don't have to, |
| especially when getting started. |
|
|
| Growing with Flask |
| |
|
|
| Once you have Flask up and running, you'll find a variety of extensions |
| available in the community to integrate your project for production. |
|
|
| As your codebase grows, you are free to make the design decisions appropriate |
| for your project. Flask will continue to provide a very simple glue layer to |
| the best that Python has to offer. You can implement advanced patterns in |
| SQLAlchemy or another database tool, introduce non-relational data persistence |
| as appropriate, and take advantage of framework-agnostic tools built for WSGI, |
| the Python web interface. |
|
|
| Flask includes many hooks to customize its behavior. Should you need more |
| customization, the Flask class is built for subclassing. If you are interested |
| in that, check out the :doc:`becomingbig` chapter. If you are curious about |
| the Flask design principles, head over to the section about :doc:`design`. |
|
|
