add more doc for component DI

Author: LordSimal

en/controllers/components.rst

@@ -147,11 +147,8 @@ in your controller, you could access it like so::
     properties they share the same 'namespace'. Be sure to not give a
     component and a model the same name.
 
-.. warning::
-
-    Component methods **don't** have access to :doc:`/development/dependency-injection`
-    like Controller actions have. Use a service class inside your controller actions
-    instead of a component if you need this functionality.
+.. versionchanged:: 5.1.0
+    Components are able to use :doc:`/development/dependency-injection` to receive services.
 
 .. _creating-a-component:
 

en/development/dependency-injection.rst

@@ -14,10 +14,14 @@ CakePHP will use the :term:`DI container` in the following situations:
 
 * Constructing controllers.
 * Calling actions on your controllers.
+* Constructing Components.
 * Constructing Console Commands.
 * Constructing Middleware by classname.
 
-A short example would be::
+Controller Example
+==================
+
+::
 
     // In src/Controller/UsersController.php
     class UsersController extends AppController
@@ -45,7 +49,10 @@ database. Because this service is injected into our controller, we can easily
 swap the implementation out with a mock object or a dummy sub-class when
 testing.
 
-Here is an example of an injected service inside a command::
+Command Example
+===============
+
+::
 
     // In src/Command/CheckUsersCommand.php
     class CheckUsersCommand extends Command
@@ -76,6 +83,43 @@ a whole to the Container and add the ``UsersService`` as an argument.
 With that you can then access that service inside the constructor
 of the command.
 
+Component Example
+=================
+
+::
+
+    // In src/Controller/Component/SearchComponent.php
+    class SearchComponent extends Command
+    {
+        public function __construct(
+            ComponentRegistry $registry,
+            array $config = [],
+            private UserService $users
+        ) {
+            parent::__construct($registry, $config);
+        }
+
+        public function something()
+        {
+            $valid = $this->users->check('all');
+        }
+    }
+
+    // In src/Application.php
+    public function services(ContainerInterface $container): void
+    {
+        $container->add(SearchComponent::class)
+            ->addArgument(ComponentRegistry::class)
+            ->addArgument([])
+            ->addArgument(AlfredFTP::class);
+        $container->add(UsersService::class);
+    }
+
+This means if you have components which need config you not only need to add
+the component config in your ``AppController`` via
+``$this->loadComponent('Search', ['key' => 'value'])`` but also need to add
+the component to the DI container manually.
+
 Adding Services
 ===============