_register_widget_update_callback() │ WP 2.8.0

Registers the update callback for a widget.

Internal function — this function is designed to be used by the kernel itself. It is not recommended to use this function in your code.

No Hooks.

Returns

null. Nothing (null).

Usage

_register_widget_update_callback( $id_base, $update_callback, $options, ...$params );

$id_base(string) (required): The base ID of a widget created by extending WP_Widget.
$update_callback(callable) (required): Update callback method for the widget.
$options(array): Widget control options. See wp_register_widget_control().
Default: empty array
...$params(mixed) (required): Optional additional parameters to pass to the callback function when it's called.

Notes

Global. Array. $wp_registered_widget_updates The registered widget updates.

Changelog

Since 2.8.0	Introduced.
Since 5.3.0	Formalized the existing and already documented `...$params` parameter by adding it to the function signature.

`_register_widget_update_callback() register widget update callback` code ^{WP 6.9.1}

wp-includes/widgets.php

function _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;
}