Editor: Add `viewStyle` property to `block.json` for frontend-only block styles

Related issue in Gutenberg: https://github.com/WordPress/gutenberg/issues/54491.

For block scripts there was already `script`, `viewScript` and `editorScript`. For block styles there was only `style` and `editorStyle`. This brings the parity.

Props gaambo.
Fixes #59673. 


Built from https://develop.svn.wordpress.org/trunk@57493


git-svn-id: http://core.svn.wordpress.org/trunk@56994 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/blocks.php

@@ -64,6 +64,7 @@ function generate_block_asset_handle( $block_name, $field_name, $index = 0 ) {
 		'viewScript'   => 'view-script',
 		'editorStyle'  => 'editor-style',
 		'style'        => 'style',
+		'viewStyle'    => 'view-style',
 	);
 	$asset_handle   = str_replace( '/', '-', $block_name ) .
 		'-' . $field_mappings[ $field_name ];
@@ -326,6 +327,7 @@ function get_block_metadata_i18n_schema() {
  * @since 6.1.0 Added support for `render` field.
  * @since 6.3.0 Added `selectors` field.
  * @since 6.4.0 Added support for `blockHooks` field.
+ * @since 6.5.0 Added support for `viewStyle` field.
  *
  * @param string $file_or_folder Path to the JSON file with metadata definition for
  *                               the block or path to the folder where the `block.json` file is located.
@@ -503,6 +505,7 @@ function register_block_type_from_metadata( $file_or_folder, $args = array() ) {
 	$style_fields = array(
 		'editorStyle' => 'editor_style_handles',
 		'style'       => 'style_handles',
+		'viewStyle'   => 'view_style_handles',
 	);
 	foreach ( $style_fields as $metadata_field_name => $settings_field_name ) {
 		if ( ! empty( $settings[ $metadata_field_name ] ) ) {

wp-includes/class-wp-block-type.php

@@ -234,6 +234,14 @@ class WP_Block_Type {
 	 */
 	public $style_handles = array();
 
+	/**
+	 * Block type front end only style handles.
+	 *
+	 * @since 6.5.0
+	 * @var string[]
+	 */
+	public $view_style_handles = array();
+
 	/**
 	 * Deprecated block type properties for script and style handles.
 	 *
@@ -278,6 +286,7 @@ class WP_Block_Type {
 	 *              Deprecated the `editor_script`, `script`, `view_script`, `editor_style`, and `style` properties.
 	 * @since 6.3.0 Added the `selectors` property.
 	 * @since 6.4.0 Added the `block_hooks` property.
+	 * @since 6.5.0 Added the `view_style_handles` property.
 	 *
 	 * @see register_block_type()
 	 *
@@ -315,6 +324,7 @@ class WP_Block_Type {
 	 *     @type string[]      $view_script_handles      Block type front end only script handles.
 	 *     @type string[]      $editor_style_handles     Block type editor only style handles.
 	 *     @type string[]      $style_handles            Block type front end and editor style handles.
+	 *     @type string[]      $view_style_handles       Block type front end only style handles.
 	 * }
 	 */
 	public function __construct( $block_type, $args = array() ) {

wp-includes/class-wp-block.php

@@ -280,6 +280,12 @@ class WP_Block {
 			}
 		}
 
+		if ( ( ! empty( $this->block_type->view_style_handles ) ) ) {
+			foreach ( $this->block_type->view_style_handles as $view_style_handle ) {
+				wp_enqueue_style( $view_style_handle );
+			}
+		}
+
 		/**
 		 * Filters the content of a single block.
 		 *

wp-includes/rest-api/endpoints/class-wp-rest-block-types-controller.php

@@ -292,6 +292,7 @@ class WP_REST_Block_Types_Controller extends WP_REST_Controller {
 				'view_script_handles',
 				'editor_style_handles',
 				'style_handles',
+				'view_style_handles',
 				'variations',
 				'block_hooks',
 			),
@@ -602,6 +603,16 @@ class WP_REST_Block_Types_Controller extends WP_REST_Controller {
 					'context'     => array( 'embed', 'view', 'edit' ),
 					'readonly'    => true,
 				),
+				'view_style_handles'    => array(
+					'description' => __( 'Public facing style handles.' ),
+					'type'        => array( 'array' ),
+					'default'     => array(),
+					'items'       => array(
+						'type' => 'string',
+					),
+					'context'     => array( 'embed', 'view', 'edit' ),
+					'readonly'    => true,
+				),
 				'styles'                => array(
 					'description' => __( 'Block style variations.' ),
 					'type'        => 'array',

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '6.5-alpha-57492';
+$wp_version = '6.5-alpha-57493';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.