graphql_compose-1.0.0-beta20/src/Plugin/GraphQL/DataProducer/Field.php

<?php

declare(strict_types=1);

namespace Drupal\graphql_compose\Plugin\GraphQL\DataProducer;

use Drupal\Core\Entity\EntityInterface;
use Drupal\Core\Entity\FieldableEntityInterface;
use Drupal\Core\Field\FieldItemListInterface;
use Drupal\Core\Plugin\Context\ContextDefinition;
use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\graphql\Attribute\DataProducer;
use Drupal\graphql\GraphQL\Execution\FieldContext;
use Drupal\graphql\Plugin\GraphQL\DataProducer\DataProducerPluginBase;

/**
 * Produces a field instance from an entity.
 *
 * Can be used instead of the property path when information about the field
 * item must be queryable. The property_path resolver always returns an array
 * which sometimes causes information loss.
 */
#[DataProducer(
  id: "field",
  name: new TranslatableMarkup("Field"),
  description: new TranslatableMarkup("Selects a field from an entity."),
  produces: new ContextDefinition(
    data_type: "mixed",
    label: new TranslatableMarkup("FieldItemListInterface"),
  ),
  consumes: [
    "entity" => new ContextDefinition(
      data_type: "entity",
      label: new TranslatableMarkup("Parent entity"),
    ),
    "field" => new ContextDefinition(
      data_type: "string",
      label: new TranslatableMarkup("Field name"),
    ),
  ],
)]
class Field extends DataProducerPluginBase {

  /**
   * Finds the requested field on the entity.
   *
   * @param \Drupal\Core\Entity\EntityInterface $entity
   *   The entity that contains the field.
   * @param string $field
   *   The name of the field to return.
   * @param \Drupal\graphql\GraphQL\Execution\FieldContext $context
   *   The field context.
   *
   * @return \Drupal\Core\Field\FieldItemListInterface|null
   *   A field item list if the field exists or null if the entity is not
   *   fieldable or doesn't have the requested field.
   */
  public function resolve(EntityInterface $entity, string $field, FieldContext $context): ?FieldItemListInterface {

    if (!$entity instanceof FieldableEntityInterface || !$entity->hasField($field)) {
      return NULL;
    }

    $value = $entity->get($field);

    // A FieldableEntityInterface::get will always return a
    // FieldItemListInterface which implements AccessibleInterface. Thus no
    // further typechecking is needed.
    return $value->access('view') ? $value : NULL;
  }

}