Create a Custom Doctrine Filter

doctrine expert

Custom filters can be written by implementing the ApiPlatform\Metadata\FilterInterface interface. API Platform provides a convenient way to create Doctrine ORM and MongoDB ODM filters. If you use custom state providers, you can still create filters by implementing the previously mentioned interface, but - as API Platform isn’t aware of your persistence system’s internals - you have to create the filtering logic by yourself. Doctrine ORM filters have access to the context created from the HTTP request and to the QueryBuilder instance used to retrieve data from the database. They are only applied to collections. If you want to deal with the DQL query generated to retrieve items, extensions are the way to go. A Doctrine ORM filter is basically a class implementing the ApiPlatform\Doctrine\Orm\Filter\FilterInterface. API Platform includes a convenient abstract class implementing this interface and providing utility methods: ApiPlatform\Doctrine\Orm\Filter\AbstractFilter. Note: Doctrine MongoDB ODM filters have access to the context created from the HTTP request and to the aggregation builder instance used to retrieve data from the database and to execute complex operations on data. They are only applied to collections. If you want to deal with the aggregation pipeline generated to retrieve items, extensions are the way to go. A Doctrine MongoDB ODM filter is basically a class implementing the ApiPlatform\Doctrine\Odm\Filter\FilterInterface. API Platform includes a convenient abstract class implementing this interface and providing utility methods: ApiPlatform\Doctrine\Odm\Filter\AbstractFilter. In this example, we create a class to filter a collection by applying a regular expression to a property. The REGEXP DQL function used in this example can be found in the DoctrineExtensions library. This library must be properly installed and registered to use this example (works only with MySQL).

// src/App/Filter.php
namespace App\Filter;
use ApiPlatform\Doctrine\Orm\Filter\AbstractFilter;
use ApiPlatform\Doctrine\Orm\Util\QueryNameGeneratorInterface;
use ApiPlatform\Metadata\Operation;
use Doctrine\ORM\QueryBuilder;
use Symfony\Component\PropertyInfo\Type;
final class RegexpFilter extends AbstractFilter
{
    /*
     * Filtered properties is accessible through getProperties() method: property => strategy
     */
    protected function filterProperty(string $property, $value, QueryBuilder $queryBuilder, QueryNameGeneratorInterface $queryNameGenerator, string $resourceClass, ?Operation $operation = null, array $context = []): void
    {
        /*
         * Otherwise this filter is applied to order and page as well.
         */
        if (
            !$this->isPropertyEnabled($property, $resourceClass)
            || !$this->isPropertyMapped($property, $resourceClass)
        ) {
            return;
        }
        /*
         * Generate a unique parameter name to avoid collisions with other filters.
         */
        $parameterName = $queryNameGenerator->generateParameterName($property);
        $queryBuilder
            ->andWhere(sprintf('REGEXP(o.%s, :%s) = 1', $property, $parameterName))
            ->setParameter($parameterName, $value);
    }
    /*
     * This function is only used to hook in documentation generators (supported by Swagger and Hydra).
     */
    public function getDescription(string $resourceClass): array
    {
        if (!$this->properties) {
            return [];
        }
        $description = [];
        foreach ($this->properties as $property => $strategy) {
            $description["regexp_$property"] = [
                'property' => $property,
                'type' => Type::BUILTIN_TYPE_STRING,
                'required' => false,
                'description' => 'Filter using a regex. This will appear in the OpenAPI documentation!',
                'openapi' => [
                    'example' => 'Custom example that will be in the documentation and be the default value of the sandbox',
                    /*
                     * If true, query parameters will be not percent-encoded
                     */
                    'allowReserved' => false,
                    'allowEmptyValue' => true,
                    /*
                     * To be true, the type must be Type::BUILTIN_TYPE_ARRAY, ?product=blue,green will be ?product[]=blue&product[]=green
                     */
                    'explode' => false,
                ],
            ];
        }
        return $description;
    }
}

// src/App/Entity.php
namespace App\Entity;
use ApiPlatform\Metadata\ApiFilter;
use ApiPlatform\Metadata\ApiResource;
use App\Filter\RegexpFilter;
use Doctrine\ORM\Mapping as ORM;
#[ORM\Entity]
#[ApiResource]
#[ApiFilter(RegexpFilter::class, properties: ['title'])]
class Book
{
    #[ORM\Column(type: 'integer')]
    #[ORM\Id]
    #[ORM\GeneratedValue(strategy: 'AUTO')]
    private $id;
    #[ORM\Column]
    public string $title;
    #[ORM\Column]
    #[ApiFilter(RegexpFilter::class)]
    public string $author;
}

// src/App/Playground.php
namespace App\Playground;
use Symfony\Component\HttpFoundation\Request;
function request(): Request
{
    return Request::create('/books.jsonld?regexp_title=^[Found]', 'GET');
}

// src/DoctrineMigrations.php
namespace DoctrineMigrations;
use Doctrine\DBAL\Schema\Schema;
use Doctrine\Migrations\AbstractMigration;
final class Migration extends AbstractMigration
{
    public function up(Schema $schema): void
    {
        $this->addSql('CREATE TABLE book (id INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, title VARCHAR(255) NOT NULL, author VARCHAR(255) NOT NULL)');
    }
}

// src/App/Tests.php
namespace App\Tests;
use ApiPlatform\Playground\Test\TestGuideTrait;
use ApiPlatform\Symfony\Bundle\Test\ApiTestCase;
use App\Entity\Book;
final class BookTest extends ApiTestCase
{
    use TestGuideTrait;
    public function testAsAnonymousICanAccessTheDocumentation(): void
    {
        static::createClient()->request('GET', '/books.jsonld?regexp_title=^[Found]');
        $this->assertResponseIsSuccessful();
        $this->assertMatchesResourceCollectionJsonSchema(Book::class, '_api_/books{._format}_get_collection');
        $this->assertJsonContains([
            'hydra:search' => [
                '@type' => 'hydra:IriTemplate',
                'hydra:template' => '/books.jsonld{?regexp_title,regexp_author}',
                'hydra:variableRepresentation' => 'BasicRepresentation',
                'hydra:mapping' => [
                    [
                        '@type' => 'IriTemplateMapping',
                        'variable' => 'regexp_title',
                        'property' => 'title',
                        'required' => false,
                    ],
                    [
                        '@type' => 'IriTemplateMapping',
                        'variable' => 'regexp_author',
                        'property' => 'author',
                        'required' => false,
                    ],
                ],
            ],
        ]);
    }
}

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