Changeset 55086 for trunk/src/wp-includes/global-styles-and-settings.php

Timestamp:

01/18/2023 11:38:16 AM (3 years ago)

Author:

hellofromTonya

Message:

Themes: Introduce wp_theme_has_theme_json() for public consumption.

Adds wp_theme_has_theme_json() for public consumption, to replace the private internal Core-only WP_Theme_JSON_Resolver::theme_has_support() method. This new global function checks if a theme or its parent has a theme.json file.

For performance, results are cached as an integer 1 or 0 in the 'theme_json' group with 'wp_theme_has_theme_json' key. This is a non-persistent cache. Why? To make the derived data from theme.json is always fresh from the potential modifications done via hooks that can use dynamic data (modify the stylesheet depending on some option, settings depending on user permissions, etc.).

Also adds a new public function wp_clean_theme_json_cache() to clear the cache on 'switch_theme' and start_previewing_theme'.

References:

• ​Gutenberg PR 45168 Add wp_theme_has_theme_json as a public API to know whether a theme has a theme.json.
• ​Gutenberg PR 45380 Deprecate WP_Theme_JSON_Resolver:theme_has_support().
• ​Gutenberg PR 46150 Make theme.json object caches non-persistent.
• ​Gutenberg PR 45979 Don't check if constants set by wp_initial_constants() are defined.
• ​Gutenberg PR 45950 Cleaner logic in wp_theme_has_theme_json.

Follow-up to [54493], [53282], [52744], [52049], [50959].

Props oandregal, afragen, alexstine, aristath, azaozz, costdev, flixos90, hellofromTonya, mamaduka, mcsf, ocean90, spacedmonkey.
Fixes #56975.

File:

• trunk/src/wp-includes/global-styles-and-settings.php (modified) (3 diffs)

trunk/src/wp-includes/global-styles-and-settings.php

@@ -103 +103 @@
     $tree = WP_Theme_JSON_Resolver::get_merged_data();
 
-    $supports_theme_json = WP_Theme_JSON_Resolver::theme_has_support();
+    $supports_theme_json = wp_theme_has_theme_json();
     if ( empty( $types ) && ! $supports_theme_json ) {
         $types = array( 'variables', 'presets', 'base-layout-styles' );
@@ -185 +185 @@
     }
 
-    $supports_theme_json = WP_Theme_JSON_Resolver::theme_has_support();
+    $supports_theme_json = wp_theme_has_theme_json();
 
     $origins = array( 'default', 'theme', 'custom' );
@@ -256 +256 @@
     }
 }
+
+/**
+ * Checks whether a theme or its parent has a theme.json file.
+ *
+ * @since 6.2.0
+ *
+ * @return bool Returns true if theme or its parent has a theme.json file, false otherwise.
+ */
+function wp_theme_has_theme_json() {
+    /*
+     * By using the 'theme_json' group, this data is marked to be non-persistent across requests.
+     * @see `wp_cache_add_non_persistent_groups()`.
+     *
+     * The rationale for this is to make sure derived data from theme.json
+     * is always fresh from the potential modifications done via hooks
+     * that can use dynamic data (modify the stylesheet depending on some option,
+     * settings depending on user permissions, etc.).
+     * For some of the existing hooks to modify theme.json behavior:
+     * @see https://make.wordpress.org/core/2022/10/10/filters-for-theme-json-data/
+     *
+     * A different alternative considered was to invalidate the cache upon certain
+     * events such as options add/update/delete, user meta, etc.
+     * It was judged not enough, hence this approach.
+     * @see https://github.com/WordPress/gutenberg/pull/45372
+     */
+    $cache_group       = 'theme_json';
+    $cache_key         = 'wp_theme_has_theme_json';
+    $theme_has_support = wp_cache_get( $cache_key, $cache_group );
+
+    /*
+     * $theme_has_support is stored as an 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
+     * @see https://developer.wordpress.org/reference/functions/wp_cache_get/
+     *
+     * Ignore cache when `WP_DEBUG` is enabled, so it doesn't interfere with the theme
+     * developer's workflow.
+     *
+     * @todo Replace `WP_DEBUG` once an "in development mode" check is available in Core.
+     */
+    if ( ! WP_DEBUG && is_int( $theme_has_support ) ) {
+        return (bool) $theme_has_support;
+    }
+
+    // Does the theme have its own theme.json?
+    $theme_has_support = is_readable( get_stylesheet_directory() . '/theme.json' );
+
+    // 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' );
+    }
+
+    $theme_has_support = $theme_has_support ? 1 : 0;
+
+    wp_cache_set( $cache_key, $theme_has_support, $cache_group );
+
+    return (bool) $theme_has_support;
+}
+
+/**
+ * Cleans the caches under the theme_json group.
+ *
+ * @since 6.2.0
+ */
+function wp_clean_theme_json_cache() {
+    wp_cache_delete( 'wp_theme_has_theme_json', 'theme_json' );
+    WP_Theme_JSON_Resolver::clean_cached_data();
+}