Title: WP_Widget_Factory::register
Published: April 25, 2014
Last modified: April 28, 2025

---

# WP_Widget_Factory::register( string|WP_Widget $widget )

## In this article

 * [Parameters](https://developer.wordpress.org/reference/classes/wp_widget_factory/register/?output_format=md#parameters)
 * [Source](https://developer.wordpress.org/reference/classes/wp_widget_factory/register/?output_format=md#source)
 * [Related](https://developer.wordpress.org/reference/classes/wp_widget_factory/register/?output_format=md#related)
 * [Changelog](https://developer.wordpress.org/reference/classes/wp_widget_factory/register/?output_format=md#changelog)

[ Back to top](https://developer.wordpress.org/reference/classes/wp_widget_factory/register/?output_format=md#wp--skip-link--target)

Registers a widget subclass.

## 󠀁[Parameters](https://developer.wordpress.org/reference/classes/wp_widget_factory/register/?output_format=md#parameters)󠁿

 `$widget`string|[WP_Widget](https://developer.wordpress.org/reference/classes/wp_widget/)
required

Either the name of a `WP_Widget` subclass or an instance of a `WP_Widget` subclass.

## 󠀁[Source](https://developer.wordpress.org/reference/classes/wp_widget_factory/register/?output_format=md#source)󠁿

    ```php
    public function register( $widget ) {
    	if ( $widget instanceof WP_Widget ) {
    		$this->widgets[ spl_object_hash( $widget ) ] = $widget;
    	} else {
    		$this->widgets[ $widget ] = new $widget();
    	}
    }
    ```

[View all references](https://developer.wordpress.org/reference/files/wp-includes/class-wp-widget-factory.php/)
[View on Trac](https://core.trac.wordpress.org/browser/tags/6.9.4/src/wp-includes/class-wp-widget-factory.php#L58)
[View on GitHub](https://github.com/WordPress/wordpress-develop/blob/6.9.4/src/wp-includes/class-wp-widget-factory.php#L58-L64)

## 󠀁[Related](https://developer.wordpress.org/reference/classes/wp_widget_factory/register/?output_format=md#related)󠁿

| Used by | Description | 
| [register_widget()](https://developer.wordpress.org/reference/functions/register_widget/)`wp-includes/widgets.php` |

Registers a widget.

  |

## 󠀁[Changelog](https://developer.wordpress.org/reference/classes/wp_widget_factory/register/?output_format=md#changelog)󠁿

| Version | Description | 
| [4.6.0](https://developer.wordpress.org/reference/since/4.6.0/) | Updated the `$widget` parameter to also accept a [WP_Widget](https://developer.wordpress.org/reference/classes/wp_widget/) instance object instead of simply a `WP_Widget` subclass name. | 
| [2.8.0](https://developer.wordpress.org/reference/since/2.8.0/) | Introduced. |

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