Condition.php in GraphQL 8.4

Namespace

Drupal\graphql\GraphQL\Resolver

File

src/GraphQL/Resolver/Condition.php

<?php

namespace Drupal\graphql\GraphQL\Resolver;

use Drupal\graphql\GraphQL\Execution\FieldContext;
use Drupal\graphql\GraphQL\Execution\ResolveContext;
use Drupal\graphql\GraphQL\Utility\DeferredUtility;
use GraphQL\Executor\Promise\Adapter\SyncPromise;
use GraphQL\Type\Definition\ResolveInfo;

/**
 * Conditional resolver.
 *
 * From given set of conditions and their respective resolvers it resolves the
 * one whose condition is evaluated with non empty value.
 */
class Condition implements ResolverInterface {

  /**
   * List of condition and their corresponding resolvers.
   *
   * @var array
   */
  protected $branches;

  /**
   * Condition constructor.
   *
   * @param array $branches
   */
  public function __construct(array $branches) {
    $this->branches = $branches;
  }

  /**
   * {@inheritdoc}
   */
  public function resolve($value, $args, ResolveContext $context, ResolveInfo $info, FieldContext $field) {
    $branches = $this->branches;
    while (list($condition, $resolver) = array_pad(array_shift($branches), 2, NULL)) {
      if ($condition instanceof ResolverInterface) {
        if (($condition = $condition
          ->resolve($value, $args, $context, $info, $field)) === NULL) {

          // Bail out early if a resolver returns NULL.
          continue;
        }
      }
      if ($condition instanceof SyncPromise) {
        return DeferredUtility::returnFinally($condition, function ($cond) use ($branches, $resolver, $value, $args, $context, $info, $field) {
          array_unshift($branches, [
            $cond,
            $resolver,
          ]);
          return (new Condition($branches))
            ->resolve($value, $args, $context, $info, $field);
        });
      }
      if ((bool) $condition) {

        /** @var \Drupal\graphql\GraphQL\Resolver\ResolverInterface|null $resolver */
        return $resolver ? $resolver
          ->resolve($value, $args, $context, $info, $field) : $condition;
      }
    }

    // Functional languages throw exceptions here. Should we just return NULL?
    return NULL;
  }

}

Classes

Name	Description
Condition	Conditional resolver.