Creating Custom Internal Endpoints for Blocks

Similar to the blockEditor internal endpoint, developers can also create their own pre-defined internal endpoints (to feed data to their application or blocks), as to apply a specific configuration:

Using nested mutations or not
Using namespacing or not
Pre-defining CPTs that can be queried
Any other configuration available in the Schema Configuration

The following PHP code defines a custom internal endpoint with name accessMyPortfolioData, that configures field Root.customPosts (from the "Custom Posts" module) to access the MyPortfolio CPT only:

<?php
 
declare(strict_types=1);
 
use GatoGraphQL\GatoGraphQL\PluginSkeleton\ExtensionHooks\AbstractAddCustomAdminEndpointHook;
use PoP\Root\Module\ModuleInterface;
use PoPCMSSchema\CustomPosts\Environment as CustomPostsEnvironment;
use PoPCMSSchema\CustomPosts\Module as CustomPostsModule;
 
class MyPortfolioCustomAdminEndpointHook extends AbstractAddCustomAdminEndpointHook
{
  protected function getAdminEndpointGroup(): string
  {
    return 'accessMyPortfolioData';
  }
 
  /**
   * Allow querying a specific CPT
   *
   * @param array<class-string<ModuleInterface>,array<string,mixed>> $moduleClassConfiguration [key]: Module class, [value]: Configuration
   * @return array<class-string<ModuleInterface>,array<string,mixed>> [key]: Module class, [value]: Configuration
   */
  protected function doGetPredefinedAdminEndpointModuleClassConfiguration(
    array $moduleClassConfiguration,
  ): array {
    $moduleClassConfiguration[CustomPostsModule::class][CustomPostsEnvironment::QUERYABLE_CUSTOMPOST_TYPES] = ['MyPortfolio'];
    return $moduleClassConfiguration;
  }
 
  /**
   * Do not disable any schema modules
   *
   * @param array<class-string<ModuleInterface>> $schemaModuleClassesToSkip List of `Module` class which must not initialize their Schema services
   * @return array<class-string<ModuleInterface>> List of `Module` class which must not initialize their Schema services
   */
  protected function doGetSchemaModuleClassesToSkip(
    array $schemaModuleClassesToSkip,
  ): array {
    return [];
  }
}

It must be initialized on the plugins_loaded hook:

add_action('plugins_loaded', function () {
  // Validate Gato GraphQL is installed, or exit
  if (!class_exists(\GatoGraphQL\GatoGraphQL\Plugin::class)) {
    return;
  }
 
  new MyPortfolioCustomAdminEndpointHook();
});

Finally, the endpoint is accessed by replacing param endpoint_group with the chosen name:

https://yoursite.com/wp-admin/edit.php?page=gatographql&action=execute_query&endpoint_group=accessMyPortfolioData