Block Editor: Backport the Global Styles Variations endpoint.

This include the /global-styles/themes/{theme}/variations rest endpoint into core.
The endpoint will be used by the site editor to display alternative theme styles to the user.

Props gziolo, oandregal.
See #55505.


git-svn-id: https://develop.svn.wordpress.org/trunk@53072 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-theme-json-resolver.php

@@ -449,4 +449,32 @@ class WP_Theme_JSON_Resolver {
 		static::$i18n_schema              = null;
 	}
 
+	/**
+	 * Returns the style variations defined by the theme.
+	 *
+	 * @since 6.0.0
+	 *
+	 * @return array
+	 */
+	public static function get_style_variations() {
+		$variations     = array();
+		$base_directory = get_stylesheet_directory() . '/styles';
+		if ( is_dir( $base_directory ) ) {
+			$nested_files      = new RecursiveIteratorIterator( new RecursiveDirectoryIterator( $base_directory ) );
+			$nested_html_files = iterator_to_array( new RegexIterator( $nested_files, '/^.+\.json$/i', RecursiveRegexIterator::GET_MATCH ) );
+			ksort( $nested_html_files );
+			foreach ( $nested_html_files as $path => $file ) {
+				$decoded_file = wp_json_file_decode( $path, array( 'associative' => true ) );
+				if ( is_array( $decoded_file ) ) {
+					$translated = static::translate( $decoded_file, wp_get_theme()->get( 'TextDomain' ) );
+					$variation  = ( new WP_Theme_JSON( $translated ) )->get_raw_data();
+					if ( empty( $variation['title'] ) ) {
+						$variation['title'] = basename( $path, '.json' );
+					}
+					$variations[] = $variation;
+				}
+			}
+		}
+		return $variations;
+	}
 }

src/wp-includes/rest-api/endpoints/class-wp-rest-global-styles-controller.php

@@ -38,6 +38,24 @@ class WP_REST_Global_Styles_Controller extends WP_REST_Controller {
 	 * @return void
 	 */
 	public function register_routes() {
+		register_rest_route(
+			$this->namespace,
+			'/' . $this->rest_base . '/themes/(?P<stylesheet>[\/\s%\w\.\(\)\[\]\@_\-]+)/variations',
+			array(
+				array(
+					'methods'             => WP_REST_Server::READABLE,
+					'callback'            => array( $this, 'get_theme_items' ),
+					'permission_callback' => array( $this, 'get_theme_items_permissions_check' ),
+					'args'                => array(
+						'stylesheet' => array(
+							'description' => __( 'The theme identifier' ),
+							'type'        => 'string',
+						),
+					),
+				),
+			)
+		);
+
 		// List themes global styles.
 		register_rest_route(
 			$this->namespace,
@@ -585,4 +603,53 @@ class WP_REST_Global_Styles_Controller extends WP_REST_Controller {
 
 		return $response;
 	}
+
+	/**
+	 * Checks if a given request has access to read a single theme global styles config.
+	 *
+	 * @since 6.0.0
+	 *
+	 * @param WP_REST_Request $request Full details about the request.
+	 * @return true|WP_Error True if the request has read access for the item, WP_Error object otherwise.
+	 */
+	public function get_theme_items_permissions_check( $request ) { // phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable
+		// Verify if the current user has edit_theme_options capability.
+		// This capability is required to edit/view/delete templates.
+		if ( ! current_user_can( 'edit_theme_options' ) ) {
+			return new WP_Error(
+				'rest_cannot_manage_global_styles',
+				__( 'Sorry, you are not allowed to access the global styles on this site.' ),
+				array(
+					'status' => rest_authorization_required_code(),
+				)
+			);
+		}
+
+		return true;
+	}
+
+	/**
+	 * Returns the given theme global styles variations.
+	 *
+	 * @since 6.0.0
+	 *
+	 * @param WP_REST_Request $request The request instance.
+	 *
+	 * @return WP_REST_Response|WP_Error
+	 */
+	public function get_theme_items( $request ) {
+		if ( wp_get_theme()->get_stylesheet() !== $request['stylesheet'] ) {
+			// This endpoint only supports the active theme for now.
+			return new WP_Error(
+				'rest_theme_not_found',
+				__( 'Theme not found.' ),
+				array( 'status' => 404 )
+			);
+		}
+
+		$variations = WP_Theme_JSON_Resolver::get_style_variations();
+		$response   = rest_ensure_response( $variations );
+
+		return $response;
+	}
 }