Filtering after results fetched

[CvekCoding]

Hello.
I would to be able to filter collection after receiving it from persistence layer.
Example (everything below is about GraphQl).

Parent class (just an owner of collection):

/**
 * @ApiResource()
 *
 * @ORM\Entity(repositoryClass="App\Repository\DocumentRepository")
 */
class Document
{
    /**
     * @var AbstractItem[]
     *
     * @ApiSubresource()
     *
     * @ORM\OneToMany(targetEntity="App\Entity\AbstractItem", mappedBy="document")
     */
    protected $items;
}

Child abstract class:

/**
 * @ApiResource()
 * 
 * This filter is not working for both fields:
 * @ApiFilter(SearchFilter::class, properties={"persistedData": "exact", "calculatedData": "exact"})
 *
 * @ORM\Entity(repositoryClass="App\Repository\AbstractItemRepository")
 *
 * @ORM\InheritanceType("SINGLE_TABLE")
 * @ORM\DiscriminatorColumn(name="item_type", type="string")
 * @ORM\DiscriminatorMap({
 *     "TYPE1"="App\Entity\Item1",
 *     "TYPE2"="App\Entity\Item2"
 * })
 */
abstract class AbstractItem
{
    /**
     * @var Document
     *
     * @ORM\ManyToOne(targetEntity="App\Entity\Document", inversedBy="items")
     */
    protected $document;
}

Inheritance classes:

/**
 * @ApiResource()
 *
 * @ORM\Entity(repositoryClass="App\Repository\Item1")
 */
class Item1 extends AbstractItem
{
   // Data calculates somehow and is not persisted directly in ORM
   public $calculatedData;

   // Data persisted in ORM and can be class-specific
   public $persistedData;
}

/**
 * @ApiResource()
 *
 * @ORM\Entity(repositoryClass="App\Repository\Item2")
 */
class Item2 extends AbstractItem
{
   public $calculatedData;

   public $persistedData;
}

if then I launch query it doesnt work:

{
  document(id: "api/documents/1") {
     items(persistedData: "foo", calculatedData: "bar") {
        persistedData
        calculatedData
     }
  }
}

Due to the fact that both calculatedData and persistedData fields are presented in final classes but not in AbstractItem, I cant use built-in AbstractFilter on AbstractItem for several reasons:

• some data is not even persisted so ORM filter is not applicable
• some data is not visible from AbstractItem.

If Im right and there is no a proper way to filter/order by these fields (correct me please if Im wrong), I would like to propose to add feature - allow to process query results after receiving them from persistence layer and before further processing. I think here:

core/src/Bridge/Symfony/Bundle/DataProvider/TraceableChainCollectionDataProvider.php

Line 73 in 125dec9

return $results ?? [];

[CvekCoding]

I think as a solution for my example above I can create SubresourceDataProvider for the class AbstractItem, parse context's filter data and make any custom filterings.
But anyway WDYT about post-fetch filtering feature?

[teohhanhui]

I think your problem is specific to GraphQL, as when using REST it's easy to do in the controller action / custom listener / etc.

/me waits for the GraphQL experts to help you.

[CvekCoding]

I solved the problem through the custom Filter and custom DataProvider this way:

final class AbstractItemProvider implements RestrictedDataProviderInterface, SubresourceDataProviderInterface
{
    private $alreadyInvoked = false;

    private $subresourceDataProvider;

    public function __construct(SubresourceDataProviderInterface $subresourceDataProvider)
    {
        $this->subresourceDataProvider = $subresourceDataProvider;
    }

    public function supports(string $resourceClass, string $operationName = null, array $context = []): bool
    {
        return !$this->alreadyInvoked && AbstractItem::class === $resourceClass;
    }

    public function getSubresource(string $resourceClass, array $identifiers, array $context, string $operationName = null)
    {
        $this->alreadyInvoked = true;

        $collection = $this->subresourceDataProvider->getSubresource($resourceClass, $identifiers, $context);

        return $this->myCustomFilteringOrderingLogic(collection, $context);
    }
}

The cons is that I return just an array, so I dont have paginator features at my result.
Please, let me know if there is a better solution based on existing functionality. Thanks.

[stale[bot]]

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