docs: parameters documentation

core/filters.md

@@ -1660,3 +1660,195 @@ The next filters are not related to how the data is fetched but rather to how th
 #[ApiFilter(PropertyFilter::class, arguments: ['parameterName' => 'foobar'])]
 #[ApiFilter(GroupFilter::class, arguments: ['parameterName' => 'foobargroups'])]
 ```
+
+## Parameters
+
+An option exists to declare parameters on a Resource or an Operation through the `parameters` property. 
+
+```php
+namespace App\ApiResource;
+
+use ApiPlatform\Metadata\GetCollection;
+use ApiPlatform\Metadata\QueryParameter;
+
+// This parameter "page" works only on /books
+#[GetCollection(uriTemplate: '/books', parameters: ['page' => new QueryParameter])]
+// This parameter is available on every operations, key is mandatory
+#[QueryParameter(key: 'q', property: 'hydra:freetextQuery')]
+class Book {}
+```
+
+Note that `property` is used to document the Hydra view. You can also specify an [OpenAPI Parameter](https://api-platform.com/docs/references/OpenApi/Model/Parameter/) if needed.
+
+### Alter the Operation via a parameter
+
+A parameter can alter the current Operation context, to do so use a `ApiPlatform\State\ParameterProviderInterface`: 
+
+```php
+class GroupsParameterProvider implements ParameterProviderInterface {
+    public function provider(Parameter $parameter, array $uriVariables = [], array $context = []): HttpOperation 
+    {
+        $request = $context['request'];
+        return $context['operation']->withNormalizationContext(['groups' => $request->query->all('groups')]);
+    }
+}
+```
+
+Then plug this provider on your parameter:
+
+```php
+namespace App\ApiResource;
+
+use ApiPlatform\Metadata\HeaderParameter;
+
+#[Get(parameters: ['groups' => new HeaderParameter(provider: GroupsParameterProvider::class)])]
+class Book {
+    public string $id;
+}
+```
+
+If you don't have autoconfiguration enabled, declare the parameter as a tagged service: 
+
+```yaml
+services:
+    ApiPlatform\Tests\Fixtures\TestBundle\Parameter\CustomGroupParameterProvider:
+        tags:
+            - name: 'api_platform.parameter_provider'
+              key: 'ApiPlatform\Tests\Fixtures\TestBundle\Parameter\CustomGroupParameterProvider'
+```
+
+### Call a filter
+
+A Parameter can also call a filter and works on filters that impact the data persistence layer (Doctrine ORM and ODM filters are supported). Let's assume, that we have an Order filter declared: 
+
+```yaml
+# config/services.yaml
+services:
+    offer.order_filter:
+        parent: 'api_platform.doctrine.orm.order_filter'
+        arguments:
+            $properties: { id: ~, name: ~ }
+            $orderParameterName: order
+        tags:  [ 'api_platform.filter' ]
+```
+
+We can use this filter specifying we want a query parameter with the `:property` placeholder: 
+
+```php
+namespace App\ApiResource;
+
+#[GetCollection(
+    uriTemplate: 'orders',
+    parameters: [
+        'order[:property]' => new QueryParameter(filter: 'offer.order_filter'),
+    ]
+)
+class Offer {
+    public string $id;
+    public string $name;
+}
+```
+
+### Decorate a Doctrine filter
+
+A filter that implements the `ApiPlatform\Doctrine\Common\Filter\PropertyAwareFilterInterface` interface can be decorated:
+
+```php
+namespace App\Doctrine\Filter;
+
+use ApiPlatform\Doctrine\Common\Filter\PropertyAwareFilterInterface;
+use ApiPlatform\Doctrine\Orm\Filter\FilterInterface;
+use ApiPlatform\Doctrine\Orm\Util\QueryNameGeneratorInterface;
+use ApiPlatform\Metadata\Operation;
+use Doctrine\ORM\QueryBuilder;
+use Symfony\Component\DependencyInjection\Attribute\Autowire;
+
+final class SearchTextAndDateFilter implements FilterInterface
+{
+    public function __construct(#[Autowire('@api_platform.doctrine.orm.search_filter.instance')] readonly FilterInterface $searchFilter, #[Autowire('@api_platform.doctrine.orm.date_filter.instance')] readonly FilterInterface $dateFilter, protected ?array $properties = null, private array $dateFilterProperties = [], private array $searchFilterProperties = [])
+    {
+    }
+
+    // This function is only used to hook in documentation generators (supported by Swagger and Hydra)
+    public function getDescription(string $resourceClass): array
+    {
+        if ($this->searchFilter instanceof PropertyAwareFilterInterface) {
+            $this->searchFilter->setProperties($this->searchFilterProperties);
+        }
+        if ($this->dateFilter instanceof PropertyAwareFilterInterface) {
+            $this->dateFilter->setProperties($this->dateFilterProperties);
+        }
+
+        return array_merge($this->searchFilter->getDescription($resourceClass), $this->dateFilter->getDescription($resourceClass));
+    }
+
+    public function apply(QueryBuilder $queryBuilder, QueryNameGeneratorInterface $queryNameGenerator, string $resourceClass, ?Operation $operation = null, array $context = []): void
+    {
+        if ($this->searchFilter instanceof PropertyAwareFilterInterface) {
+            $this->searchFilter->setProperties($this->searchFilterProperties);
+        }
+        if ($this->dateFilter instanceof PropertyAwareFilterInterface) {
+            $this->dateFilter->setProperties($this->dateFilterProperties);
+        }
+
+        $this->searchFilter->apply($queryBuilder, $queryNameGenerator, $resourceClass, $operation, ['filters' => $context['filters']['searchOnTextAndDate']] + $context);
+        $this->dateFilter->apply($queryBuilder, $queryNameGenerator, $resourceClass, $operation, ['filters' => $context['filters']['searchOnTextAndDate']] + $context);
+    }
+}
+```
+
+This can be used with parameters using attributes: 
+
+```php
+namespace App\Entity;
+
+#[GetCollection(
+    uriTemplate: 'search_filter_parameter{._format}',
+    parameters: [
+        'searchOnTextAndDate[:property]' => new QueryParameter(filter: 'app_filter_date_and_search'),
+    ]
+)]
+// Note that we link the parameter filter and this filter using the "alias" option:
+#[ApiFilter(SearchTextAndDateFilter::class, alias: 'app_filter_date_and_search', properties: ['foo', 'createdAt'], arguments: ['dateFilterProperties' => ['createdAt' => 'exclude_null'], 'searchFilterProperties' => ['foo' => 'exact']])]
+#[ORM\Entity]
+class SearchFilterParameter
+{
+    /**
+     * @var int The id
+     */
+    #[ORM\Column(type: 'integer')]
+    #[ORM\Id]
+    #[ORM\GeneratedValue(strategy: 'AUTO')]
+    private ?int $id = null;
+    #[ORM\Column(type: 'string')]
+    private string $foo = '';
+
+    #[ORM\Column(type: 'datetime_immutable', nullable: true)]
+    private ?\DateTimeImmutable $createdAt = null;
+
+    public function getId(): ?int
+    {
+        return $this->id;
+    }
+
+    public function getFoo(): string
+    {
+        return $this->foo;
+    }
+
+    public function setFoo(string $foo): void
+    {
+        $this->foo = $foo;
+    }
+
+    public function getCreatedAt(): ?\DateTimeImmutable
+    {
+        return $this->createdAt;
+    }
+
+    public function setCreatedAt(\DateTimeImmutable $createdAt): void
+    {
+        $this->createdAt = $createdAt;
+    }
+}
+```