docs(core/dtos): improve by adding other usages

Author: vinceAmstoutz

core/dto.md

@@ -213,3 +213,113 @@ final class BookRepresentationProcessor implements ProcessorInterface
     }
 }
 ```
+
+## Implementing one custom state provider with DTOs to support Get and GetCollection methods
+
+We have a state provider named `BookProvider` which retrieves our data to serve them in our API using DTOs.
+If we want to combine both Get and GetCollection methods into a single state provider as follows:
+
+```php
+<?php
+// api/src/Resource/Book.php with Symfony or app/Resource/Book.php with Laravel
+
+declare(strict_types=1);
+
+namespace App\Resource;
+
+use ApiPlatform\Metadata\ApiResource;
+use App\State\BookProvider;
+use ApiPlatform\Metadata\Get;
+use ApiPlatform\Metadata\GetCollection;
+use Doctrine\ORM\Mapping as ORM;
+use Symfony\Component\Validator\Constraints as Assert;
+
+#[Get(provider: BookProvider::class)]
+#[GetCollection (provider: BookProvider::class)]
+final class Book
+{
+    #[ORM\Id]
+    #[ORM\GeneratedValue]
+    #[ORM\Column(type: 'integer')]
+    private ?int $id = null;
+
+    #[ORM\Column(type: 'string', length: 255)]
+    #[Assert\NotBlank]
+    private string $title;
+    
+    // Other fields, accessors and mutators...
+}
+```
+
+To do that, we can create a state provider for both cases using this:
+
+```php
+<?php
+// api/src/State/BookProvider.php with Symfony or app/State/BookProvider.php with Laravel
+
+declare(strict_types=1);
+
+namespace App\Resource;
+
+use ApiPlatform\Metadata\ApiResource;
+use ApiPlatform\State\ProviderInterface;
+use ApiPlatform\Doctrine\Orm\State\CollectionProvider;
+
+final class BookProvider implements ProviderInterface
+{
+    public function __construct(
+        #[Autowire(service: CollectionProvider::class)]
+        private readonly ProviderInterface $collectionProvider,
+    ) {}
+
+    public function provide(Operation $operation, array $uriVariables = [], array $context = []): ?PostalAddress
+    {
+        $resources = $this->collectionProvider->provide($operation, $uriVariables, $context);
+        
+        $dtos = [];
+        foreach ($resources as $resource){
+            $dtos[] = new Book(
+                $resource->id,
+                $resource->title,
+                // ...
+            )
+        } 
+        
+        return $dtos;
+    }
+}
+```
+
+> [!TIP]
+> For more information and other advanced options, refer to the [screencast here](#using-data-transfer-objects-dtos).
+
+> [!NOTICE]
+> As a best practice, a class should have only one primary responsibility.
+> Combining multiple distinct actions in a single class can make it harder to maintain, test, and understand.
+> Strive for classes with a single, well-defined purpose.
+
+## DTO without response
+
+Sometimes we need DTOs to process something, but we don't need to send an object in response.
+Assuming that, we can disable the output for our API Resource using the following code:
+
+```php
+<?php
+// api/src/Resource/Book.php with Symfony or app/Resource/Book.php with Laravel
+
+declare(strict_types=1);
+
+namespace App\Resource;
+
+use ApiPlatform\Metadata\ApiResource;
+use App\Dto\BookInput;
+
+#[ApiResource(
+    input: BookInput::class,
+    output: false, // Disables the response
+)]
+final class Book	
+{
+    // ...
+}
+```