Replace hardcoded async batch allowlist with extensible registration system

* Add Scheduler::register_async_batch_callback() method for dynamic callback registration
* Remove hardcoded Migration callbacks from Scheduler class
* Update Migration class to register its callbacks through new system
* Add safety check to ensure callbacks are registered at proper time
* Maintain backward compatibility - async_batch works exactly the same way
* Enable any class to add async batch jobs without modifying core files

Author: obenland

includes/class-migration.php

@@ -7,7 +7,6 @@
 
 namespace Activitypub;
 
-use Activitypub\Activity\Actor;
 use Activitypub\Collection\Actors;
 use Activitypub\Collection\Extra_Fields;
 use Activitypub\Collection\Followers;
@@ -25,6 +24,11 @@ class Migration {
 	 */
 	public static function init() {
 		self::maybe_migrate();
+
+		Scheduler::register_async_batch_callback( 'activitypub_migrate_from_0_17', array( self::class, 'migrate_from_0_17' ) );
+		Scheduler::register_async_batch_callback( 'activitypub_update_comment_counts', array( self::class, 'update_comment_counts' ) );
+		Scheduler::register_async_batch_callback( 'activitypub_create_post_outbox_items', array( self::class, 'create_post_outbox_items' ) );
+		Scheduler::register_async_batch_callback( 'activitypub_create_comment_outbox_items', array( self::class, 'create_comment_outbox_items' ) );
 	}
 
 	/**

includes/class-scheduler.php

@@ -27,23 +27,17 @@ class Scheduler {
 	 *
 	 * @var array
 	 */
-	private static $batch_callbacks = array();
+	private static $batch_callbacks = array(
+		'activitypub_send_activity'  => array( Dispatcher::class, 'send_to_followers' ),
+		'activitypub_retry_activity' => array( Dispatcher::class, 'retry_send_to_followers' ),
+	);
 
 	/**
 	 * Initialize the class, registering WordPress hooks.
 	 */
 	public static function init() {
 		self::register_schedulers();
 
-		self::$batch_callbacks = array(
-			'activitypub_send_activity'               => array( Dispatcher::class, 'send_to_followers' ),
-			'activitypub_retry_activity'              => array( Dispatcher::class, 'retry_send_to_followers' ),
-			'activitypub_migrate_from_0_17'           => array( Migration::class, 'migrate_from_0_17' ),
-			'activitypub_update_comment_counts'       => array( Migration::class, 'update_comment_counts' ),
-			'activitypub_create_post_outbox_items'    => array( Migration::class, 'create_post_outbox_items' ),
-			'activitypub_create_comment_outbox_items' => array( Migration::class, 'create_comment_outbox_items' ),
-		);
-
 		// Follower Cleanups.
 		\add_action( 'activitypub_update_remote_actors', array( self::class, 'update_remote_actors' ) );
 		\add_action( 'activitypub_cleanup_remote_actors', array( self::class, 'cleanup_remote_actors' ) );
@@ -52,10 +46,6 @@ public static function init() {
 		\add_action( 'activitypub_async_batch', array( self::class, 'async_batch' ), 10, 99 );
 		\add_action( 'activitypub_send_activity', array( self::class, 'async_batch' ), 10, 3 );
 		\add_action( 'activitypub_retry_activity', array( self::class, 'async_batch' ), 10, 3 );
-		\add_action( 'activitypub_migrate_from_0_17', array( self::class, 'async_batch' ) );
-		\add_action( 'activitypub_update_comment_counts', array( self::class, 'async_batch' ), 10, 2 );
-		\add_action( 'activitypub_create_post_outbox_items', array( self::class, 'async_batch' ), 10, 2 );
-		\add_action( 'activitypub_create_comment_outbox_items', array( self::class, 'async_batch' ), 10, 2 );
 		\add_action( 'activitypub_reprocess_outbox', array( self::class, 'reprocess_outbox' ) );
 		\add_action( 'activitypub_outbox_purge', array( self::class, 'purge_outbox' ) );
 
@@ -81,6 +71,28 @@ public static function register_schedulers() {
 		do_action( 'activitypub_register_schedulers' );
 	}
 
+	/**
+	 * Register a batch callback for async processing.
+	 *
+	 * @param string   $hook     The cron event hook name.
+	 * @param callable $callback The callback to execute.
+	 */
+	public static function register_async_batch_callback( $hook, $callback ) {
+		if ( \did_action( 'init' ) && ! \doing_action( 'init' ) ) {
+			\_doing_it_wrong( __METHOD__, 'Async batch callbacks should be registered before or during the init action.', '5.2.0' );
+			return;
+		}
+
+		if ( ! \is_callable( $callback ) ) {
+			return;
+		}
+
+		self::$batch_callbacks[ $hook ] = $callback;
+
+		// Register the WordPress action hook to trigger async_batch.
+		\add_action( $hook, array( self::class, 'async_batch' ), 10, 99 );
+	}
+
 	/**
 	 * Schedule all ActivityPub schedules.
 	 */

tests/includes/class-test-migration.php

@@ -7,6 +7,8 @@
 
 namespace Activitypub\Tests;
 
+use Activitypub\Activity\Actor;
+use Activitypub\Collection\Actors;
 use Activitypub\Collection\Extra_Fields;
 use Activitypub\Collection\Followers;
 use Activitypub\Collection\Outbox;
@@ -475,7 +477,8 @@ public function test_create_outbox_items_batching() {
 	/**
 	 * Test async upgrade with multiple arguments.
 	 *
-	 * @covers ::async_upgrade
+	 * @covers ::update_comment_counts
+	 * @covers \Activitypub\Scheduler::async_batch
 	 */
 	public function test_async_upgrade_multiple_args() {
 		// Test that multiple arguments are passed correctly.