Add a new endpoint that exposes block editor settings through the REST API

lib/class-wp-rest-block-editor-global-styles-settings-controller.php

@@ -0,0 +1,125 @@
+<?php
+/**
+ * REST API: WP_REST_Block_Editor_Global_Styles_Settings_Controller class
+ *
+ * @package    WordPress
+ * @subpackage REST_API
+ */
+
+/**
+ * Core class used to retrieve the block editor global styles settings via the REST API.
+ *
+ * @see WP_REST_Controller
+ */
+class WP_REST_Block_Editor_Global_Styles_Settings_Controller extends WP_REST_Controller {
+	/**
+	 * Constructs the controller.
+	 */
+	public function __construct() {
+		$this->namespace = 'wp/v2';
+		$this->rest_base = 'block-editor-global-styles-settings';
+	}
+
+	/**
+	 * Registers the necessary REST API routes.
+	 */
+	public function register_routes() {
+		register_rest_route(
+			$this->namespace,
+			'/' . $this->rest_base,
+			array(
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( $this, 'get_items' ),
+					'permission_callback' => array( $this, 'get_items_permissions_check' ),
+				),
+				'schema' => array( $this, 'get_public_item_schema' ),
+			)
+		);
+	}
+
+	/**
+	 * Checks whether a given request has permission to read block editor settings
+	 *
+	 * @since 5.8.0
+	 *
+	 * @param WP_REST_Request $request Full details about the request.
+	 *
+	 * @return WP_Error|bool True if the request has permission, WP_Error object otherwise.
+	 */
+	public function get_items_permissions_check( $request ) {// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+		if ( ! current_user_can( 'edit_posts' ) ) {
+			$error = __( 'Sorry, you are not allowed to read the block editor settings.', 'gutenberg' );
+			return new WP_Error( 'rest_cannot_read_settings', $error, array( 'status' => rest_authorization_required_code() ) );
+		}
+
+		return true;
+	}
+
+	/**
+	 * Returns the block editor's global styles settings
+	 *
+	 * @since 5.8.0
+	 *
+	 * @param WP_REST_Request $request Full details about the request.
+	 *
+	 * @return WP_Error|WP_REST_Response Response object on success, or WP_Error object on failure.
+	 */
+	public function get_items( $request ) {// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+		$settings = apply_filters( 'block_editor_global_styles_rest_settings', array() );
+
+		return rest_ensure_response( $settings );
+	}
+
+	/**
+	 * Retrieves the block editor's global styles schema, conforming to JSON Schema.
+	 *
+	 * @since 5.8.0
+	 *
+	 * @return array Item schema data.
+	 */
+	public function get_item_schema() {
+		if ( $this->schema ) {
+			return $this->add_additional_fields_schema( $this->schema );
+		}
+
+		$this->schema = array(
+			'$schema'    => 'http://json-schema.org/draft-04/schema#',
+			'title'      => 'block-editor-global-styles-settings-item',
+			'type'       => 'object',
+			'properties' => array(
+				'colors'                   => array(
+					'description' => __( 'Active theme colors.', 'gutenberg' ),
+					'type'        => 'array',
+					'context'     => array( 'view' ),
+				),
+
+				'gradients'                => array(
+					'description' => __( 'Active theme gradients.', 'gutenberg' ),
+					'type'        => 'array',
+					'context'     => array( 'view' ),
+				),
+
+				'globalStyles'             => array(
+					'description' => __( 'Theme support for global styles.', 'gutenberg' ),
+					'type'        => 'boolean',
+					'context'     => array( 'view' ),
+				),
+
+				'globalStylesUserEntityId' => array(
+					'description' => __( 'User entity id for Global styles settings.', 'gutenberg' ),
+					'type'        => 'integer',
+					'context'     => array( 'view' ),
+				),
+
+				'globalStylesBaseStyles'   => array(
+					'description' => __( 'Global styles settings.', 'gutenberg' ),
+					'type'        => 'object',
+					'context'     => array( 'view' ),
+				),
+			),
+		);
+
+		return $this->add_additional_fields_schema( $this->schema );
+	}
+}

lib/global-styles.php

@@ -250,6 +250,40 @@ function_exists( 'gutenberg_is_edit_site_page' ) &&
 	return $settings;
 }
 
+/**
+ * Adds the necessary data of Global Styles for the REST API.
+ *
+ * @param array $settings Existing block editor settings.
+ * @return array New block editor settings
+ */
+function gutenberg_global_styles_rest_settings( $settings ) {
+	$color_palette = current( (array) get_theme_support( 'editor-color-palette' ) );
+	if ( false !== $color_palette ) {
+		$settings['colors'] = $color_palette;
+	}
+
+	$gradient_presets = current( (array) get_theme_support( 'editor-gradient-presets' ) );
+	if ( false !== $gradient_presets ) {
+		$settings['gradients'] = $gradient_presets;
+	}
+
+	$settings['globalStyles'] = WP_Theme_JSON_Resolver::theme_has_support();
+
+	if (
+		WP_Theme_JSON_Resolver::theme_has_support() &&
+		gutenberg_is_fse_theme()
+		) {
+		$theme_support_data = gutenberg_experimental_global_styles_get_theme_support_settings( $settings );
+		$user_cpt_id        = WP_Theme_JSON_Resolver::get_user_custom_post_type_id();
+		$base_styles        = WP_Theme_JSON_Resolver::get_merged_data( $theme_support_data, 'theme' )->get_raw_data();
+
+		$settings['globalStylesUserEntityId'] = $user_cpt_id;
+		$settings['globalStylesBaseStyles']   = $base_styles;
+	}
+
+	return $settings;
+}
+
 /**
  * Register CPT to store/access user data.
  *
@@ -265,6 +299,7 @@ function gutenberg_experimental_global_styles_register_user_cpt() {
 
 add_action( 'init', 'gutenberg_experimental_global_styles_register_user_cpt' );
 add_filter( 'block_editor_settings', 'gutenberg_experimental_global_styles_settings', PHP_INT_MAX );
+add_filter( 'block_editor_global_styles_rest_settings', 'gutenberg_global_styles_rest_settings', PHP_INT_MAX );
 add_action( 'wp_enqueue_scripts', 'gutenberg_experimental_global_styles_enqueue_assets' );
 
 

lib/load.php

@@ -61,6 +61,9 @@ function gutenberg_is_experiment_enabled( $name ) {
 	if ( ! class_exists( 'WP_REST_Templates_Controller' ) ) {
 		require_once __DIR__ . '/full-site-editing/class-wp-rest-templates-controller.php';
 	}
+	if ( ! class_exists( 'WP_REST_Block_Editor_Global_Styles_Settings_Controller' ) ) {
+		require dirname( __FILE__ ) . '/class-wp-rest-block-editor-global-styles-settings-controller.php';
+	}
 	/**
 	* End: Include for phase 2
 	*/

lib/rest-api.php

@@ -73,6 +73,15 @@ function gutenberg_register_batch_endpoint() {
 }
 add_action( 'rest_api_init', 'gutenberg_register_batch_endpoint' );
 
+/**
+ * Registers the Block types REST API routes.
+ */
+function gutenberg_register_block_editor_global_styles_settings() {
+	$editor_settings = new WP_REST_Block_Editor_Global_Styles_Settings_Controller();
+	$editor_settings->register_routes();
+}
+add_action( 'rest_api_init', 'gutenberg_register_block_editor_global_styles_settings' );
+
 /**
  * Hook in to the nav menu item post type and enable a post type rest endpoint.
  *