load.php

<?php
/**
 * Load API functions, register scripts and actions, etc.
 *
 * @package gutenberg
 */

if ( ! defined( 'ABSPATH' ) ) {
	die( 'Silence is golden.' );
}

/**
 * Checks whether the Gutenberg experiment is enabled.
 *
 * @since 6.7.0
 *
 * @param string $name The name of the experiment.
 *
 * @return bool True when the experiment is enabled.
 */
function gutenberg_is_experiment_enabled( $name ) {
	$experiments = get_option( 'gutenberg-experiments' );
	return ! empty( $experiments[ $name ] );
}

// These files only need to be loaded if within a rest server instance
// which this class will exist if that is the case.
if ( class_exists( 'WP_REST_Controller' ) ) {
	/**
	* Start: Include for phase 2
	*/
	if ( ! class_exists( 'WP_REST_Widget_Forms' ) ) {
		require dirname( __FILE__ ) . '/class-wp-rest-widget-forms.php';
	}
	if ( ! class_exists( 'WP_REST_Widget_Areas_Controller' ) ) {
		require dirname( __FILE__ ) . '/class-experimental-wp-widget-blocks-manager.php';
		require dirname( __FILE__ ) . '/class-wp-rest-widget-areas-controller.php';
	}
	if ( ! class_exists( 'WP_REST_Block_Directory_Controller' ) ) {
		require dirname( __FILE__ ) . '/class-wp-rest-block-directory-controller.php';
	}
	if ( ! class_exists( 'WP_REST_Block_Types_Controller' ) ) {
		require dirname( __FILE__ ) . '/class-wp-rest-block-types-controller.php';
	}
	if ( ! class_exists( 'WP_REST_Menus_Controller' ) ) {
		require_once dirname( __FILE__ ) . '/class-wp-rest-menus-controller.php';
	}
	if ( ! class_exists( 'WP_REST_Menu_Items_Controller' ) ) {
		require_once dirname( __FILE__ ) . '/class-wp-rest-menu-items-controller.php';
	}
	if ( ! class_exists( 'WP_REST_Menu_Locations_Controller' ) ) {
		require_once dirname( __FILE__ ) . '/class-wp-rest-menu-locations-controller.php';
	}
	if ( ! class_exists( 'WP_Rest_Customizer_Nonces' ) ) {
		require_once dirname( __FILE__ ) . '/class-wp-rest-customizer-nonces.php';
	}
	/**
	* End: Include for phase 2
	*/

	require dirname( __FILE__ ) . '/rest-api.php';
}

if ( ! class_exists( 'WP_Block_Styles_Registry' ) ) {
	require dirname( __FILE__ ) . '/class-wp-block-styles-registry.php';
}

if ( ! class_exists( 'WP_Block_Patterns_Registry' ) ) {
	require dirname( __FILE__ ) . '/class-wp-block-patterns-registry.php';
}

if ( ! class_exists( 'WP_Block_Pattern_Categories_Registry' ) ) {
	require dirname( __FILE__ ) . '/class-wp-block-pattern-categories-registry.php';
}

if ( ! class_exists( 'WP_Block' ) ) {
	require dirname( __FILE__ ) . '/class-wp-block.php';
}

if ( ! class_exists( 'WP_Block_List' ) ) {
	require dirname( __FILE__ ) . '/class-wp-block-list.php';
}

require dirname( __FILE__ ) . '/compat.php';
require dirname( __FILE__ ) . '/utils.php';

require dirname( __FILE__ ) . '/blocks.php';
require dirname( __FILE__ ) . '/templates.php';
require dirname( __FILE__ ) . '/template-parts.php';
require dirname( __FILE__ ) . '/template-loader.php';
require dirname( __FILE__ ) . '/client-assets.php';
require dirname( __FILE__ ) . '/block-directory.php';
require dirname( __FILE__ ) . '/demo.php';
require dirname( __FILE__ ) . '/widgets.php';
require dirname( __FILE__ ) . '/widgets-page.php';
require dirname( __FILE__ ) . '/navigation-page.php';
require dirname( __FILE__ ) . '/experiments-page.php';
require dirname( __FILE__ ) . '/customizer.php';
require dirname( __FILE__ ) . '/edit-site-page.php';
require dirname( __FILE__ ) . '/editor-features.php';
require dirname( __FILE__ ) . '/global-styles.php';