add: [DOC] Custom Subresources Data Provider examples

core/data-providers.md

@@ -239,6 +239,49 @@ final class BlogPostItemDataProvider implements ItemDataProviderInterface, Restr
     }
 }
 ```
+## Custom Subresources Data Provider
+
+You can add custom logic or update subresources data provider with the SubresourceDataProviderInterface .
+
+```php
+<?php
+// api/src/DataProvider/BlogPostCollectionDataProvider.php
+
+namespace App\DataProvider;
+
+use ApiPlatform\Core\DataProvider\SubresourceDataProviderInterface;
+use ApiPlatform\Core\DataProvider\RestrictedDataProviderInterface;
+use App\Entity\BlogPost;
+
+final class BlogPostCollectionDataProvider implements SubresourceDataProviderInterface, RestrictedDataProviderInterface
+{
+    public function supports(string $resourceClass, string $operationName = null, array $context = []): bool
+    {
+        return BlogPost::class === $resourceClass;
+    }
+
+    public function getSubresource(string $resourceClass, array $identifiers, array $context, string $operationName = null): iterable
+    {
+        // Retrieve the blog post collection from somewhere
+        $blogPosts = $this->subresourceDataProvider->getSubresource($resourceClass, $identifiers, $context, $operationName);
+
+		// write your own logic
+
+		return blogPosts;
+    }
+}
+```
+
+Declare the service in your service.
+
+```yaml
+# api/config/services.yaml
+services:
+    # ...
+    'App\DataProvider\BlogPostCollectionDataProvider':
+        bind:
+            $subresourceDataProvider: '@api_platform.doctrine.orm.default.subresource_data_provider'
+```
 
 ## Community Data Providers