materio-d8/web/modules/custom/materio_graphql/src/Plugin/GraphQL/SchemaExtension/MaterioSchemaExtension.php

<?php

namespace Drupal\materio_graphql\Plugin\GraphQL\SchemaExtension;

use Drupal\graphql\GraphQL\ResolverBuilder;
use Drupal\graphql\GraphQL\ResolverRegistryInterface;
use Drupal\graphql\GraphQL\Response\ResponseInterface;
use Drupal\graphql\Plugin\GraphQL\SchemaExtension\SdlSchemaExtensionPluginBase;
use Drupal\materio_graphql\GraphQL\Response\MaterioResponse;

/**
 * @SchemaExtension(
 *   id = "materio_extension",
 *   name = "Materio extension",
 *   description = "Materio extension.",
 *   schema = "materio"
 * )
 */
class MaterioSchemaExtension extends SdlSchemaExtensionPluginBase {

  /**
   * {@inheritdoc}
   */
  public function registerResolvers(ResolverRegistryInterface $registry) {
    $builder = new ResolverBuilder();

    $registry->addFieldResolver('Query', 'materiau',
      $builder->produce('entity_load')
        ->map('type', $builder->fromValue('node'))
        ->map('bundles', $builder->fromValue(['materiau']))
        ->map('id', $builder->fromArgument('id'))
    );

    // Create materiau mutation.
    $registry->addFieldResolver('Mutation', 'createMateriau',
      $builder->produce('create_materiau')
        ->map('data', $builder->fromArgument('data'))
    );

    $registry->addFieldResolver('MateriauResponse', 'materiau',
      $builder->callback(function (MateriauResponse $response) {
        return $response->materiau();
      })
    );

    $registry->addFieldResolver('MateriauResponse', 'errors',
      $builder->callback(function (MateriauResponse $response) {
        return $response->getViolations();
      })
    );

    $registry->addFieldResolver('Materiau', 'id',
      $builder->produce('entity_id')
        ->map('entity', $builder->fromParent())
    );

    $registry->addFieldResolver('Materiau', 'uuid',
      $builder->produce('entity_uuid')
        ->map('entity', $builder->fromParent())
    );

    $registry->addFieldResolver('Materiau', 'title',
      $builder->compose(
        $builder->produce('entity_label')
          ->map('entity', $builder->fromParent())
      )
    );

    $registry->addFieldResolver('Materiau', 'author',
      $builder->compose(
        $builder->produce('entity_owner')
          ->map('entity', $builder->fromParent()),
        $builder->produce('entity_label')
          ->map('entity', $builder->fromParent())
      )
    );

    // https://github.com/drupal-graphql/graphql/blob/8.x-4.x/doc/SUMMARY.md
    // https://blog.chrismitchellonline.com/posts/custom_graphql_data/

    $registry->addFieldResolver('Materiau', 'linked_materials',
      $builder->compose(
        $builder->produce('entity_reference')
          ->map('entity', $builder->fromParent())
          ->map('field', $builder->fromValue('field_linked_materials'))
      )
    );

    $registry->addFieldResolver('Materiau', 'memo',
      $builder->produce('property_path')
        ->map('type', $builder->fromValue('entity:node'))
        ->map('value', $builder->fromParent())
        ->map('path', $builder->fromValue('field_memo.value'))
      );

    $registry->addFieldResolver('Materiau', 'images',
      $builder->produce('entity_reference')
        ->map('entity', $builder->fromParent())
        ->map('field', $builder->fromValue('field_materiau_images'))
    );

    $registry->addFieldResolver('Image', 'id',
      $builder->produce('entity_id')
        ->map('entity', $builder->fromParent())
    );

    $registry->addFieldResolver('Image', 'url',
      $builder->produce('image_url')
        ->map('entity', $builder->fromParent())
    );

    $registry->addFieldResolver('Image', 'alt',
      $builder->produce('property_path')
      ->map('type', $builder->fromValue('entity:node'))
      ->map('value', $builder->fromParent())
      ->map('path', $builder->fromValue('field_image.alt'))
    );

    $registry->addFieldResolver('Image', 'style_minicard',
      $builder->produce('image_derivative')
        ->map('entity', $builder->fromParent())
        ->map('style', $builder->fromValue('card_medium_half'))
    );


    // Response type resolver.
    $registry->addTypeResolver('Response', [
      __CLASS__,
      'resolveResponse',
    ]);
  }

  /**
   * Resolves the response type.
   *
   * @param \Drupal\graphql\GraphQL\Response\ResponseInterface $response
   *   Response object.
   *
   * @return string
   *   Response type.
   *
   * @throws \Exception
   *   Invalid response type.
   */
  public static function resolveResponse(ResponseInterface $response): string {
    // Resolve content response.
    if ($response instanceof MateriauResponse) {
      return 'MateriauResponse';
    }
    throw new \Exception('Invalid response type.');
  }

}