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classes that interact with a database. |
Adding a service class that interacts with Entity Framework Core |
(and your database) with the singleton lifecycle (or other lifecycles) |
can cause problems, because of how Entity Framework Core |
manages database connections per request under the hood. To |
avoid that, always use the scoped lifecycle for services that |
interact with Entity Framework Core. |
The TodoController that depends on an injected ITodoItemService will |
be blissfully unaware of the change in services classes, but under the |
hood it'll be using Entity Framework Core and talking to a real database! |
Test it out |
Start up the application and navigate to http://localhost:5000/todo . |
The fake items are gone, and your application is making real queries to |
the database. There doesn't happen to be any saved to-do items, so it's |
59 |
Create a new service class |
blank for now. |
In the next chapter, you'll add more features to the application, starting |
with the ability to create new to-do items. |
60 |
Add more features |
Add more features |
Now that you've connected to a database using Entity Framework Core, |
you're ready to add some more features to the application. First, you'll |
make it possible to add new to-do items using a form. |
61 |
Add new to-do items |
Add new to-do items |
The user will add new to-do items with a simple form below the list: |
Adding this feature requires a few steps: |
Adding a form to the view |
Creating a new action on the controller to handle the form |
Adding code to the service layer to update the database |
Add a form |
The Views/Todo/Index.cshtml view has a placeholder for the Add Item |
form: |
<div class="panel-footer add-item-form"> |
<!-- TODO: Add item form --> |
</div> |
To keep things separate and organized, you'll create the form as a partial |
view. A partial view is a small piece of a larger view that lives in a |
separate file. |
Create an AddItemPartial.cshtml view: |
Views/Todo/AddItemPartial.cshtml |
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Add new to-do items |
@model TodoItem |
<form asp-action="AddItem" method="POST"> |
<label asp-for="Title">Add a new item:</label> |
<input asp-for="Title"> |
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