Fix: wrong followers URL in "to" attribute of posts (#874)

* draft that shows potentially right behavior for what is set on the to attribute on posts

* use Actor Object instead

* reformat

---------

Co-authored-by: Matthias Pfefferle <[email protected]>

Author: Menrath

includes/transformer/class-post.php

@@ -4,15 +4,16 @@
 use WP_Post;
 use Activitypub\Shortcodes;
 use Activitypub\Model\Blog;
-use Activitypub\Transformer\Base;
 use Activitypub\Collection\Users;
+use Activitypub\Transformer\Base;
 
 use function Activitypub\esc_hashtag;
 use function Activitypub\is_single_user;
 use function Activitypub\get_enclosures;
-use function Activitypub\generate_post_summary;
-use function Activitypub\get_rest_url_by_path;
 use function Activitypub\site_supports_blocks;
+use function Activitypub\get_rest_url_by_path;
+use function Activitypub\is_user_type_disabled;
+use function Activitypub\generate_post_summary;
 
 /**
  * WordPress Post Transformer
@@ -25,6 +26,13 @@
  * - Activitypub\Activity\Base_Object
  */
 class Post extends Base {
+	/**
+	 * The User as Actor Object.
+	 *
+	 * @var Activitypub\Activity\Actor
+	 */
+	private $actor_object = null;
+
 	/**
 	 * Returns the ID of the WordPress Post.
 	 *
@@ -71,18 +79,46 @@ public function to_object() {
 				$this->get_locale() => $this->get_content(),
 			)
 		);
-		$path = sprintf( 'actors/%d/followers', intval( $post->post_author ) );
 
 		$object->set_to(
 			array(
 				'https://www.w3.org/ns/activitystreams#Public',
-				get_rest_url_by_path( $path ),
+				$this->get_actor_object()->get_followers(),
 			)
 		);
 
 		return $object;
 	}
 
+	/**
+	 * Returns the User-Object of the Author of the Post.
+	 *
+	 * If `single_user` mode is enabled, the Blog-User is returned.
+	 *
+	 * @return Activitypub\Activity\Actor The User-Object.
+	 */
+	protected function get_actor_object() {
+		if ( $this->actor_object ) {
+			return $this->actor_object;
+		}
+
+		$blog_user         = new Blog();
+		$this->actor_object = $blog_user;
+
+		if ( is_single_user() ) {
+			return $blog_user;
+		}
+
+		$user = Users::get_by_id( $this->wp_object->post_author );
+
+		if ( $user && ! is_wp_error( $user ) ) {
+			$this->actor_object = $user;
+			return $user;
+		}
+
+		return $blog_user;
+	}
+
 	/**
 	 * Returns the ID of the Post.
 	 *
@@ -128,19 +164,7 @@ public function get_url() {
 	 * @return string The User-URL.
 	 */
 	protected function get_attributed_to() {
-		$blog_user = new Blog();
-
-		if ( is_single_user() ) {
-			return $blog_user->get_url();
-		}
-
-		$user = Users::get_by_id( $this->wp_object->post_author );
-
-		if ( $user && ! is_wp_error( $user ) ) {
-			return $user->get_url();
-		}
-
-		return $blog_user->get_url();
+		return $this->get_actor_object()->get_url();
 	}
 
 	/**