wp-includes/widgets.php:604Registers the update callback for a widget.
$id_basestring$update_callbackcallable$optionsarrayoptionalarray()$paramsmixedfunction _register_widget_update_callback( $id_base, $update_callback, $options = array(), ...$params ) { global $wp_registered_widget_updates; if ( isset( $wp_registered_widget_updates[ $id_base ] ) ) { if ( empty( $update_callback ) ) { unset( $wp_registered_widget_updates[ $id_base ] ); } return; } $widget = array( 'callback' => $update_callback, 'params' => $params, ); $widget = array_merge( $widget, $options ); $wp_registered_widget_updates[ $id_base ] = $widget;}Introduced in 2.8.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/widgets.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.