or. * @param callable $callback The function to generate ID for. * @param int $priority Unused. The order in which the functions * associated with a particular action are executed. * @return string Unique function ID for usage as array key. */ function _wp_filter_build_unique_id( $hook_name, $callback, $priority ) { if ( is_string( $callback ) ) { return $callback; } if ( is_object( $callback ) ) { // Closures are currently implemented as objects. $callback = array( $callback, '' ); } else { $callback = (array) $callback; } if ( is_object( $callback[0] ) ) { // Object class calling. return spl_object_hash( $callback[0] ) . $callback[1]; } elseif ( is_string( $callback[0] ) ) { // Static calling. return $callback[0] . '::' . $callback[1]; } }