Refactor notification system to use action hooks instead

.github/changelog/2223-from-description

@@ -0,0 +1,4 @@
+Significance: minor
+Type: changed
+
+Standardized notification handling with new hooks for better extensibility and consistency.

includes/class-notification.php

@@ -9,6 +9,8 @@
 
 /**
  * Notification class.
+ *
+ * @deprecated unreleased Use action hooks like 'activitypub_handled_{type}' instead.
  */
 class Notification {
 	/**
@@ -48,6 +50,8 @@ class Notification {
 	 * @param int    $target   The WordPress User-Id.
 	 */
 	public function __construct( $type, $actor, $activity, $target ) {
+		\_deprecated_class( __CLASS__, 'unreleased', 'Use action hooks like "activitypub_handled_{type}" instead.' );
+
 		$this->type   = $type;
 		$this->actor  = $actor;
 		$this->object = $activity;
@@ -63,15 +67,19 @@ public function send() {
 		/**
 		 * Action to send ActivityPub notifications.
 		 *
+		 * @deprecated unreleased Use "activitypub_handled_{$type}" instead.
+		 *
 		 * @param Notification $instance The notification object.
 		 */
-		do_action( 'activitypub_notification', $this );
+		\do_action_deprecated( 'activitypub_notification', array( $this ), 'unreleased', "activitypub_handled_{$type}" );
 
 		/**
 		 * Type-specific action to send ActivityPub notifications.
 		 *
+		 * @deprecated unreleased Use "activitypub_handled_{$type}" instead.
+		 *
 		 * @param Notification $instance The notification object.
 		 */
-		do_action( "activitypub_notification_{$type}", $this );
+		\do_action_deprecated( "activitypub_notification_{$type}", array( $this ), 'unreleased', "activitypub_handled_{$type}" );
 	}
 }

includes/collection/class-followers.php

@@ -69,13 +69,13 @@ public static function add_follower( $user_id, $actor ) {
 	/**
 	 * Remove a Follower.
 	 *
-	 * @param int $post_id The ID of the remote Actor.
-	 * @param int $user_id The ID of the WordPress User.
+	 * @param \WP_Post|int $post_or_id The ID of the remote Actor.
+	 * @param int          $user_id    The ID of the WordPress User.
 	 *
 	 * @return bool True on success, false on failure.
 	 */
-	public static function remove( $post_id, $user_id ) {
-		$post = \get_post( $post_id );
+	public static function remove( $post_or_id, $user_id ) {
+		$post = \get_post( $post_or_id );
 
 		if ( ! $post ) {
 			return false;
@@ -93,7 +93,7 @@ public static function remove( $post_id, $user_id ) {
 		 */
 		\do_action( 'activitypub_followers_pre_remove_follower', $post, $user_id, Remote_Actors::get_actor( $post ) );
 
-		return \delete_post_meta( $post_id, self::FOLLOWER_META_KEY, $user_id );
+		return \delete_post_meta( $post->ID, self::FOLLOWER_META_KEY, $user_id );
 	}
 
 	/**

includes/collection/class-interactions.php

@@ -89,7 +89,7 @@ public static function update_comment( $activity ) {
 	 *
 	 * @param array $activity Activity array.
 	 *
-	 * @return array|false Comment data or `false` on failure.
+	 * @return array|string|int|\WP_Error|false Comment data or `false` on failure.
 	 */
 	public static function add_reaction( $activity ) {
 		$url               = object_to_uri( $activity['object'] );

includes/handler/class-accept.php

@@ -10,7 +10,6 @@
 use Activitypub\Collection\Following;
 use Activitypub\Collection\Outbox;
 use Activitypub\Collection\Remote_Actors;
-use Activitypub\Notification;
 
 use function Activitypub\object_to_uri;
 
@@ -22,19 +21,8 @@ class Accept {
 	 * Initialize the class, registering WordPress hooks.
 	 */
 	public static function init() {
-		\add_action(
-			'activitypub_inbox_accept',
-			array( self::class, 'handle_accept' ),
-			10,
-			2
-		);
-
-		\add_filter(
-			'activitypub_validate_object',
-			array( self::class, 'validate_object' ),
-			10,
-			3
-		);
+		\add_action( 'activitypub_inbox_accept', array( self::class, 'handle_accept' ), 10, 2 );
+		\add_filter( 'activitypub_validate_object', array( self::class, 'validate_object' ), 10, 3 );
 	}
 
 	/**
@@ -60,16 +48,18 @@ public static function handle_accept( $accept, $user_id ) {
 			return;
 		}
 
-		Following::accept( $actor_post, $user_id );
-
-		// Send notification.
-		$notification = new Notification(
-			'accept',
-			$actor_post->guid,
-			$accept,
-			$user_id
-		);
-		$notification->send();
+		$result  = Following::accept( $actor_post, $user_id );
+		$success = ! \is_wp_error( $result );
+
+		/**
+		 * Fires after an ActivityPub Accept activity has been handled.
+		 *
+		 * @param array              $accept  The ActivityPub activity data.
+		 * @param int                $user_id The local user ID.
+		 * @param bool               $success True on success, false otherwise.
+		 * @param \WP_Post|\WP_Error $result  The remote actor post or error.
+		 */
+		\do_action( 'activitypub_handled_accept', $accept, $user_id, $success, $result );
 	}
 
 	/**

includes/handler/class-announce.php

@@ -23,12 +23,7 @@ class Announce {
 	 * Initialize the class, registering WordPress hooks.
 	 */
 	public static function init() {
-		\add_action(
-			'activitypub_inbox_announce',
-			array( self::class, 'handle_announce' ),
-			10,
-			3
-		);
+		\add_action( 'activitypub_inbox_announce', array( self::class, 'handle_announce' ), 10, 3 );
 	}
 
 	/**
@@ -106,21 +101,22 @@ public static function maybe_save_announce( $activity, $user_id ) {
 			return;
 		}
 
-		$state    = Interactions::add_reaction( $activity );
-		$reaction = null;
+		$success = false;
+		$result  = Interactions::add_reaction( $activity );
 
-		if ( $state && ! is_wp_error( $state ) ) {
-			$reaction = get_comment( $state );
+		if ( $result && ! is_wp_error( $result ) ) {
+			$success = true;
+			$result  = get_comment( $result );
 		}
 
 		/**
-		 * Fires after an Announce has been saved.
+		 * Fires after an ActivityPub Announce activity has been handled.
 		 *
-		 * @param array $activity The activity-object.
-		 * @param int   $user_id  The id of the local blog-user.
-		 * @param mixed $state    The state of the reaction.
-		 * @param mixed $reaction The reaction.
+		 * @param array                            $activity The ActivityPub activity data.
+		 * @param int                              $user_id  The local user ID.
+		 * @param bool                             $success  True on success, false otherwise.
+		 * @param array|string|int|\WP_Error|false $result   The WP_Comment object of the created announce/repost comment, or null if creation failed.
 		 */
-		do_action( 'activitypub_handled_announce', $activity, $user_id, $state, $reaction );
+		\do_action( 'activitypub_handled_announce', $activity, $user_id, $success, $result );
 	}
 }

includes/handler/class-create.php

@@ -22,19 +22,8 @@ class Create {
 	 * Initialize the class, registering WordPress hooks.
 	 */
 	public static function init() {
-		\add_action(
-			'activitypub_inbox_create',
-			array( self::class, 'handle_create' ),
-			10,
-			3
-		);
-
-		\add_filter(
-			'activitypub_validate_object',
-			array( self::class, 'validate_object' ),
-			10,
-			3
-		);
+		\add_action( 'activitypub_inbox_create', array( self::class, 'handle_create' ), 10, 3 );
+		\add_filter( 'activitypub_validate_object', array( self::class, 'validate_object' ), 10, 3 );
 	}
 
 	/**
@@ -72,22 +61,23 @@ public static function handle_create( $activity, $user_id, $activity_object = nu
 			return;
 		}
 
-		$state    = Interactions::add_comment( $activity );
-		$reaction = null;
+		$success = false;
+		$result  = Interactions::add_comment( $activity );
 
-		if ( $state && ! \is_wp_error( $state ) ) {
-			$reaction = \get_comment( $state );
+		if ( $result && ! \is_wp_error( $result ) ) {
+			$success = true;
+			$result  = \get_comment( $result );
 		}
 
 		/**
-		 * Fires after a Create activity has been handled.
+		 * Fires after an ActivityPub Create activity has been handled.
 		 *
-		 * @param array                      $activity The activity-object.
-		 * @param int                        $user_id  The id of the local blog-user.
-		 * @param \WP_Comment|\WP_Error      $state    The comment object or WP_Error.
-		 * @param \WP_Comment|\WP_Error|null $reaction The reaction object or WP_Error.
+		 * @param array                            $activity The ActivityPub activity data.
+		 * @param int                              $user_id  The local user ID.
+		 * @param bool                             $success  True on success, false otherwise.
+		 * @param array|string|int|\WP_Error|false $result   The WP_Comment object of the created comment, or null if creation failed.
 		 */
-		\do_action( 'activitypub_handled_create', $activity, $user_id, $state, $reaction );
+		\do_action( 'activitypub_handled_create', $activity, $user_id, $success, $result );
 	}
 
 	/**