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wp_register_sidebar_widget()

wp_register_sidebar_widget( int|string $id, string $name, callable $output_callback, array $options = array(), mixed $params )

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Register an instance of a widget.

Description

The default widget option is ‘classname’ that can be overridden.

The function can also be used to un-register widgets when $output_callback parameter is an empty string.

Parameters

$idint|stringrequired
Widget ID.
$namestringrequired
Widget display title.
$output_callbackcallablerequired
Run when widget is called.
$optionsarrayoptional
An array of supplementary widget options for the instance.
  • classname string
    Class name for the widget’s HTML container. Default is a shortened version of the output callback name.
  • description string
    Widget description for display in the widget administration panel and/or theme.
  • show_instance_in_rest bool
    Whether to show the widget’s instance settings in the REST API.
    Only available for WP_Widget based widgets.

Default:array()

$paramsmixedoptional
Optional additional parameters to pass to the callback function when it’s called.

Source

function wp_register_sidebar_widget( $id, $name, $output_callback, $options = array(), ...$params ) {
	global $wp_registered_widgets, $wp_registered_widget_controls, $wp_registered_widget_updates, $_wp_deprecated_widgets_callbacks;

	$id = strtolower( $id );

	if ( empty( $output_callback ) ) {
		unset( $wp_registered_widgets[ $id ] );
		return;
	}

	$id_base = _get_widget_id_base( $id );
	if ( in_array( $output_callback, $_wp_deprecated_widgets_callbacks, true ) && ! is_callable( $output_callback ) ) {
		unset( $wp_registered_widget_controls[ $id ] );
		unset( $wp_registered_widget_updates[ $id_base ] );
		return;
	}

	$defaults = array( 'classname' => $output_callback );
	$options  = wp_parse_args( $options, $defaults );
	$widget   = array(
		'name'     => $name,
		'id'       => $id,
		'callback' => $output_callback,
		'params'   => $params,
	);
	$widget   = array_merge( $widget, $options );

	if ( is_callable( $output_callback ) && ( ! isset( $wp_registered_widgets[ $id ] ) || did_action( 'widgets_init' ) ) ) {

		/**
		 * Fires once for each registered widget.
		 *
		 * @since 3.0.0
		 *
		 * @param array $widget An array of default widget arguments.
		 */
		do_action( 'wp_register_sidebar_widget', $widget );
		$wp_registered_widgets[ $id ] = $widget;
	}
}

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Hooks

do_action( ‘wp_register_sidebar_widget’, array $widget )

Fires once for each registered widget.

UsesDescription
did_action()wp-includes/plugin.php

Retrieves the number of times an action has been fired during the current request.

_get_widget_id_base()wp-includes/widgets.php

Retrieves the widget ID base value.

wp_parse_args()wp-includes/functions.php

Merges user defined arguments into defaults array.

do_action()wp-includes/plugin.php

Calls the callback functions that have been added to an action hook.

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Used byDescription
register_sidebar_widget()wp-includes/deprecated.php

Register widget for sidebar with backward compatibility.

WP_Widget::_register_one()wp-includes/class-wp-widget.php

Registers an instance of the widget class.

wp_unregister_sidebar_widget()wp-includes/widgets.php

Remove widget from sidebar.

Changelog

VersionDescription
5.8.0Added show_instance_in_rest option.
5.3.0Formalized the existing and already documented ...$params parameter by adding it to the function signature.
2.2.0Introduced.

User Contributed Notes

  1. Skip to note 2 content
    Codex
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    Example
    The following code will create a widget called “Wpdocs Widget” which will become available in the WordPress Administrative Panels. The widget can then be dragged to an available sidebar for display.

    Note that this widget can only be used once in exactly 1 of the sidebars. For recursive widgets (widgets you can add to multiple times and add to multiple sidebars) please see the Register Widget function.

    wp_register_sidebar_widget(
	'wpdocs_widget_1',		// wpdocs unique widget id
	'Wpdocs Widget',		// widget name
	'wpdocs_widget_display',	// callback function
	array(				// options
		'description' => 'Description of what the widget does'
	)
);

/**
 * Display the wpdocs widget
 */
function wpdocs_widget_display($args) {
   echo $args['before_widget'];
   echo $args['before_title'] . 'The Wpdocs Widget' .  $args['after_title'];
   echo $args['after_widget'];
   // Print some HTML for the widget to display here.
   echo __( 'Wpdocs Widget Test', 'textdomain' );
}

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