Update wp_theme_has_theme_json to use WP_Object_Cache (#45543)

Co-authored-by: Felix Arntz <felixarntz@users.noreply.github.com>
Co-authored-by: Miguel Torres <miguel.torres@automattic.com>
Co-authored-by: Jonny Harris <spacedmonkey@users.noreply.github.com>

lib/compat/wordpress-6.2/default-filters.php

@@ -17,11 +17,6 @@
  * @package gutenberg
  */
 
-/**
- * Note for backport: we should also remove the existing filters:
- *
- * > add_action( 'switch_theme', array( 'WP_Theme_JSON_Resolver', 'clean_cached_data' ) );
- * > add_action( 'start_previewing_theme', array( 'WP_Theme_JSON_Resolver', 'clean_cached_data' ) );
- */
-add_action( 'switch_theme', 'wp_theme_clean_theme_json_cached_data' );
-add_action( 'start_previewing_theme', 'wp_theme_clean_theme_json_cached_data' );
+add_action( 'switch_theme', 'wp_theme_has_theme_json_clean_cache' );
+add_action( 'start_previewing_theme', 'wp_theme_has_theme_json_clean_cache' );
+add_action( 'upgrader_process_complete', '_wp_theme_has_theme_json_clean_cache_upon_upgrading_active_theme' );

lib/compat/wordpress-6.2/get-global-styles-and-settings.php

@@ -9,39 +9,69 @@
 	/**
 	 * Whether a theme or its parent have a theme.json file.
 	 *
-	 * @param boolean $clear_cache Whether the cache should be cleared and theme support recomputed. Default is false.
+	 * The result would be cached via the WP_Object_Cache.
+	 * It can be cleared by calling wp_theme_has_theme_json_clean_cache().
 	 *
 	 * @return boolean
 	 */
-	function wp_theme_has_theme_json( $clear_cache = false ) {
-		static $theme_has_support = null;
+	function wp_theme_has_theme_json() {
+		$cache_group       = 'theme_json';
+		$cache_key         = 'wp_theme_has_theme_json';
+		$theme_has_support = wp_cache_get( $cache_key, $cache_group );
 
-		if ( true === $clear_cache ) {
-			$theme_has_support = null;
-		}
-
-		if ( null !== $theme_has_support ) {
-			return $theme_has_support;
+		/**
+		 * $theme_has_support is stored as a int in the cache.
+		 *
+		 * The reason not to store it as a boolean is to avoid working
+		 * with the $found parameter which apparently had some issues in some implementations
+		 * https://developer.wordpress.org/reference/functions/wp_cache_get/
+		 */
+		if ( 0 === $theme_has_support || 1 === $theme_has_support ) {
+			return (bool) $theme_has_support;
 		}
 
 		// Has the own theme a theme.json?
-		$theme_has_support = is_readable( get_stylesheet_directory() . '/theme.json' );
+		$theme_has_support = is_readable( get_stylesheet_directory() . '/theme.json' ) ? 1 : 0;
 
 		// Look up the parent if the child does not have a theme.json.
-		if ( ! $theme_has_support ) {
-			$theme_has_support = is_readable( get_template_directory() . '/theme.json' );
+		if ( 0 === $theme_has_support ) {
+			$theme_has_support = is_readable( get_template_directory() . '/theme.json' ) ? 1 : 0;
 		}
 
-		return $theme_has_support;
+		wp_cache_set( $cache_key, $theme_has_support, $cache_group );
+
+		return (bool) $theme_has_support;
+	}
+}
+
+if ( ! function_exists( 'wp_theme_has_theme_json_clean_cache' ) ) {
+	/**
+	 * Function to clean the cache used by wp_theme_has_theme_json method.
+	 */
+	function wp_theme_has_theme_json_clean_cache() {
+		wp_cache_delete( 'wp_theme_has_theme_json', 'theme_json' );
 	}
 }
 
-if ( ! function_exists( 'wp_theme_clean_theme_json_cached_data' ) ) {
+if ( ! function_exists( '_wp_theme_has_theme_json_clean_cache_upon_upgrading_active_theme' ) ) {
 	/**
-	 * Clean theme.json related cached data.
+	 * Private function to clean the cache used by wp_theme_has_theme_json method.
+	 *
+	 * It is hooked into the `upgrader_process_complete` action.
+	 *
+	 * @see default-filters.php
+	 *
+	 * @param WP_Upgrader $upgrader Instance of WP_Upgrader class.
+	 * @param array       $options Metadata that identifies the data that is updated.
 	 */
-	function wp_theme_clean_theme_json_cached_data() {
-		wp_theme_has_theme_json( true );
-		WP_Theme_JSON_Resolver_Gutenberg::clean_cached_data();
+	function _wp_theme_has_theme_json_clean_cache_upon_upgrading_active_theme( $upgrader, $options ) {
+		// The cache only needs cleaning when the active theme was updated.
+		if (
+			'update' === $options['action'] &&
+			'theme' === $options['type'] &&
+			( isset( $options['themes'][ get_stylesheet() ] ) || isset( $options['themes'][ get_template() ] ) )
+		) {
+			wp_theme_has_theme_json_clean_cache();
+		}
 	}
 }