Events

A PSR-14 event dispatcher is included for handling events.

Query Builder Event

Each top level connection uses a Doctrine QueryBuilder object. This QueryBuilder object may be modified to filter the data for the logged in user and such. For instance, this can be used as a security layer and can be used to make customizations to QueryBuilder objects. QueryBuilders are built then triggered through an event. Listen to this event and modify the passed QueryBuilder to apply your security.

Event names are passed as a second parameter to a $driver->resolve().

You may specify an event name to resolve a connection. Only this event will fire when the QueryBuilder is created. The default ‘filter.querybuilder’ will not fire.

In the code below the custom event Artist::class . '.queryBuilder' will fire:

use ApiSkeletons\Doctrine\ORM\GraphQL\Driver;
use App\ORM\Entity\Artist;
use GraphQL\Type\Definition\ObjectType;
use GraphQL\Type\Schema;

$schema = new Schema([
  'query' => new ObjectType([
      'name' => 'query',
      'fields' => [
          'artists' => [
              'type' => $driver->connection($driver->type(Artist::class)),
              'args' => [
                  'filter' => $driver->filter(Artist::class),
              ],
              'resolve' => $driver->resolve(Artist::class, Artist::class . '.queryBuilder'),
          ],
      ],
  ]),
]);

To listen for this event and add filtering, such as filtering for the context user, create at least one listener. You may add multiple listeners.

use ApiSkeletons\Doctrine\ORM\GraphQL\Event\QueryBuilder;
use League\Event\EventDispatcher;

$driver->get(EventDispatcher::class)->subscribeTo(Artist::class . '.queryBuilder',
    function(QueryBuilder $event) {
        $event->getQueryBuilder()
            ->innerJoin('entity.user', 'user') // The default entity alias is always `entity`
            ->andWhere($event->getQueryBuilder()->expr()->eq('user.id', ':userId'))
            ->setParameter('userId', $event->getContext()['user']->getId())
            ;
    }
);

The FilterQueryBuilder event has one function in addition to getters for all resolve parameters:

  • getQueryBuilder - Will return a query builder with the user specified filters already applied.

Criteria Event

When an association is resolved from an entity or another association you may listen to the Criteria Event to add additional criteria for filtering the association if you assigned an event name in the attributes.

use ApiSkeletons\Doctrine\ORM\GraphQL\Attribute as GraphQL;
use ApiSkeletons\Doctrine\ORM\GraphQL\Event\Criteria;
use App\ORM\Entity\Artist;
use League\Event\EventDispatcher;

#[GraphQL\Entity]
class Artist
{
    #[GraphQL\Field]
    public $id;

    #[GraphQL\Field]
    public $name;

    #[GraphQL\Association(filterCriteriaEventName: self::class . '.performances.criteria')]
    public $performances;
}

// Add a listener to your driver
$driver->get(EventDispatcher::class)->subscribeTo(
    Artist::class . '.performances.criteria',
    function (Criteria $event): void {
        $event->getCriteria()->andWhere(
            $event->getCriteria()->expr()->eq('isDeleted', false)
        );
    },
);

The FilterQueryBuilder event has one function in addition to getters for all resolve parameters:

  • getCriteria - Will return a Criteria object with the user specified filters already applied.

Modify an Entity Definition

You may modify the array used to define an entity type before it is created. This can be used for generated data and the like. You must attach to events before defining your GraphQL schema.

Events of this type are named Entity::class . '.definition' and the event name cannot be modified.

use ApiSkeletons\Doctrine\ORM\GraphQL\Driver;
use ApiSkeletons\Doctrine\ORM\GraphQL\Event\EntityDefinition;
use App\ORM\Entity\Artist;
use GraphQL\Type\Definition\ResolveInfo;
use League\Event\EventDispatcher;

$driver = new Driver($entityManager);

$driver->get(EventDispatcher::class)->subscribeTo(
    Artist::class . '.definition',
    static function (EntityDefinition $event): void {
        $definition = $event->getDefinition();

        // In order to modify the fields you must resolve the closure
        $fields = $definition['fields']();

        // Add a custom field to show the name without a prefix of 'The'
        $fields['nameUnprefix'] = [
            'type' => Type::string(),
            'description' => 'A computed dynamically added field',
            'resolve' => static function ($objectValue, array $args, $context, ResolveInfo $info): mixed {
                return trim(str_replace('The', '', $objectValue->getName()));
            },
        ];

        $definition['fields'] = $fields;
    }
);

The EntityDefinition event has one function:

  • getDefinition - Will return an ArrayObject with the ObjectType definition. Because this is an ArrayObject you may manipulate it as needed and the value is set by reference, just like the QueryBuilder event above.

A clever use of this event is to add a new field for related data and specify a custom FilterQueryBuilder event in the $driver->resolve() function.

Manually change the Metadata

You may modify the metadata directly when built. This event must be subscribed to immediatly after creating the driver. See Metadata documentation.

This event is named 'metadata.build'.

use ApiSkeletons\Doctrine\ORM\GraphQL\Driver;
use ApiSkeletons\Doctrine\ORM\GraphQL\Event\Metadata;
use App\ORM\Entity\Performance;
use League\Event\EventDispatcher;

$driver = new Driver($entityManager);

$driver->get(EventDispatcher::class)->subscribeTo(
    'metadata.build',
    static function (Metadata $event): void {
        $metadata = $event->getMetadata();

        $metadata[Performance::class]['limit'] = 100;
    },
);

The BuildMetadata event has one function:

  • getMetadata - Will return an ArrayObject with the metadata. Because this is an ArrayObject you may manipulate it as needed and the value is set by reference, just like the QueryBuilder event above.


This is documentation for API-Skeletons/doctrine-orm-graphql. Please add your ★ star to the project.

Authored by API Skeletons.