# activitypub/3.2.3/includes/handler/class-undo.php

ActivityPub, version 3.2.3. 76 lines.

- Page: https://pluginprobe.com/plugins/activitypub/3.2.3/code/includes/handler/class-undo.php
- Raw: https://pluginprobe.com/plugins/activitypub/3.2.3/raw/includes/handler/class-undo.php
- Modified: 2024-09-09T07:49:38+00:00

Line numbers below start at 1. Link to a line or a range by appending a fragment to the
page URL, for example `https://pluginprobe.com/plugins/activitypub/3.2.3/code/includes/handler/class-undo.php#L10-L20`.

```php
<?php
namespace Activitypub\Handler;

use Activitypub\Collection\Users;
use Activitypub\Collection\Followers;
use Activitypub\Comment;

use function Activitypub\object_to_uri;

/**
 * Handle Undo requests
 */
class Undo {
	/**
	 * Initialize the class, registering WordPress hooks
	 */
	public static function init() {
		\add_action(
			'activitypub_inbox_undo',
			array( self::class, 'handle_undo' )
		);
	}

	/**
	 * Handle "Unfollow" requests
	 *
	 * @param array $activity The JSON "Undo" Activity
	 * @param int   $user_id  The ID of the ID of the WordPress User
	 */
	public static function handle_undo( $activity ) {
		if (
			! isset( $activity['object']['type'] ) ||
			! isset( $activity['object']['object'] )
		) {
			return;
		}

		$type = $activity['object']['type'];

		// Handle "Unfollow" requests
		if ( 'Follow' === $type ) {
			$user_id = object_to_uri( $activity['object']['object'] );
			$user = Users::get_by_resource( $user_id );

			if ( ! $user || is_wp_error( $user ) ) {
				// If we can not find a user,
				// we can not initiate a follow process
				return;
			}

			$user_id = $user->get__id();
			$actor   = object_to_uri( $activity['actor'] );

			Followers::remove_follower( $user_id, $actor );
		}

		// Handle "Undo" requests for "Like" and "Create" activities
		if ( in_array( $type, array( 'Like', 'Create', 'Announce' ), true ) ) {
			if ( ACTIVITYPUB_DISABLE_INCOMING_INTERACTIONS ) {
				return;
			}

			$object_id = object_to_uri( $activity['object'] );
			$comment   = Comment::object_id_to_comment( esc_url_raw( $object_id ) );

			if ( empty( $comment ) ) {
				return;
			}

			$state = wp_trash_comment( $comment );

			do_action( 'activitypub_handled_undo', $activity, $user_id, isset( $state ) ? $state : null, null );
		}
	}
}

```