Pagination in custom data provider (without doctrine or ES)

[kpn13]

Hi,

I have a custom data provider which call an API for providing data. Is there a builtin solution to use pagination, filter, etc for my array of results or do I have to make my own PaginatorInterface implementation ?

[mumy81]

You can use built-in extensions; filter, pagination e.t.c built-in solutions are extensions indeed.

I have implemented like that:

In services.yaml: you should register your custom data provider, you should notice that arguments, collectionExtensions are tagged with 'api_platform.doctrine.orm.query_extension.collection'.

App\DataProvider\CollectionDataProvider:
      tags: [{ name: 'api_platform.collection_data_provider' }]
      arguments:
          $collectionExtensions: !tagged api_platform.doctrine.orm.query_extension.collection
      # Autoconfiguration must be disabled to set a custom priority
      autoconfigure: false

My Custom Collection Data Provider implements the below Interfaces, these built-in interfaces are used in original built in data providier.

use ApiPlatform\Core\DataProvider\CollectionDataProviderInterface;
use ApiPlatform\Core\DataProvider\RestrictedDataProviderInterface;
use Doctrine\Common\Persistence\ManagerRegistry;
use ApiPlatform\Core\Bridge\Doctrine\Orm\Util\QueryNameGenerator;

final class CollectionDataProvider implements CollectionDataProviderInterface, RestrictedDataProviderInterface
{
    private $collectionExtensions;
    private $managerRegistry;
    private $excludedResources;

    public function __construct(ManagerRegistry $managerRegistry, /* iterable */ $collectionExtensions = [])
    {
        $this->collectionExtensions = $collectionExtensions;
        $this->managerRegistry = $managerRegistry;
    }

The getCollection method is the main method at here: It takes 3 parameters like at below:
Here you walk through all of the built-in extensions by applying current collection into them. Extensions apply their logic to queryBuilder so queryBuilder changes by extensions. End of loop, the queryBuilder contains conditions to provide filters, pagination etc.

public function getCollection(string $resourceClass, string $operationName = null, array $context = [])
 {
     $manager = $this->managerRegistry->getManagerForClass($resourceClass);
     $repository = $manager->getRepository($resourceClass);
     $queryBuilder = $repository->createQueryBuilder('e');
     $queryNameGenerator = new QueryNameGenerator();

     foreach ($this->collectionExtensions as $extension) {

         $extension->applyToCollection($queryBuilder, $queryNameGenerator, $resourceClass, $operationName, $context);

         if ($extension instanceof QueryResultCollectionExtensionInterface && $extension->supportsResult($resourceClass, $operationName, $context)) {
             return $extension->getResult($queryBuilder, $resourceClass, $operationName, $context);
         }
     }

return $queryBuilder->getQuery()->getResult();
}

[soyuka]

A good example of custom pagination is done at https://github.com/soyuka/esql#paginator I'll maybe introduce this abstraction to API Platform at some point. In the meantime closing this as not a bug.