wp_get_global_styles_custom_css

WordPress Version: 6.2

/**
 * Gets the global styles custom css from theme.json.
 *
 * @since 6.2.0
 *
 * @return string Stylesheet.
 */
function wp_get_global_styles_custom_css()
{
    if (!wp_theme_has_theme_json()) {
        return '';
    }
    /*
     * 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.
     */
    $can_use_cached = !WP_DEBUG;
    /*
     * 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.).
     * See 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_key = 'wp_get_global_styles_custom_css';
    $cache_group = 'theme_json';
    if ($can_use_cached) {
        $cached = wp_cache_get($cache_key, $cache_group);
        if ($cached) {
            return $cached;
        }
    }
    $tree = WP_Theme_JSON_Resolver::get_merged_data();
    $stylesheet = $tree->get_custom_css();
    if ($can_use_cached) {
        wp_cache_set($cache_key, $stylesheet, $cache_group);
    }
    return $stylesheet;
}