Add actor blocking functionality with list table interface

.github/changelog/2027-from-description

@@ -0,0 +1,4 @@
+Significance: minor
+Type: added
+
+Add actor blocking functionality with list table interface for managing blocked users and site-wide blocks

.github/changelog/add-block-action

@@ -0,0 +1,4 @@
+Significance: minor
+Type: added
+
+Follower lists now include the option to block individual accounts.

includes/class-activitypub.php

@@ -11,6 +11,7 @@
 use Activitypub\Collection\Actors;
 use Activitypub\Collection\Extra_Fields;
 use Activitypub\Collection\Followers;
+use Activitypub\Collection\Following;
 use Activitypub\Collection\Inbox;
 use Activitypub\Collection\Outbox;
 
@@ -47,6 +48,8 @@ public static function init() {
 		\add_filter( 'default_post_metadata', array( self::class, 'default_post_metadata' ), 10, 3 );
 
 		\add_filter( 'activitypub_get_actor_extra_fields', array( Extra_Fields::class, 'default_actor_extra_fields' ), 10, 2 );
+		\add_action( 'activitypub_add_user_block', array( Followers::class, 'remove_blocked_actors' ), 10, 3 );
+		\add_action( 'activitypub_add_user_block', array( Following::class, 'remove_blocked_actors' ), 10, 3 );
 
 		// Add support for ActivityPub to custom post types.
 		foreach ( \get_option( 'activitypub_support_post_types', array( 'post' ) ) as $post_type ) {

includes/class-cli.php

@@ -7,8 +7,6 @@
 
 namespace Activitypub;
 
-use Activitypub\Collection\Actors;
-use Activitypub\Collection\Followers;
 use Activitypub\Collection\Outbox;
 
 /**

includes/class-moderation.php

@@ -8,27 +8,42 @@
 namespace Activitypub;
 
 use Activitypub\Activity\Activity;
+use Activitypub\Collection\Actors;
+use Activitypub\Collection\Blocked_Actors;
 
 /**
  * ActivityPub Moderation class.
  *
  * Handles user-specific blocking and site-wide moderation.
  */
 class Moderation {
+
+	/**
+	 * Block type constants.
+	 */
+	const TYPE_ACTOR   = 'actor';
+	const TYPE_DOMAIN  = 'domain';
+	const TYPE_KEYWORD = 'keyword';
+
+	/**
+	 * Post meta key for blocked actors.
+	 */
+	const BLOCKED_ACTORS_META_KEY = '_activitypub_blocked_by';
+
 	/**
 	 * User meta key for blocked keywords.
 	 */
 	const USER_META_KEYS = array(
-		'domain'  => 'activitypub_blocked_domains',
-		'keyword' => 'activitypub_blocked_keywords',
+		self::TYPE_DOMAIN  => 'activitypub_blocked_domains',
+		self::TYPE_KEYWORD => 'activitypub_blocked_keywords',
 	);
 
 	/**
 	 * Option key for site-wide blocked keywords.
 	 */
 	const OPTION_KEYS = array(
-		'domain'  => 'activitypub_site_blocked_domains',
-		'keyword' => 'activitypub_site_blocked_keywords',
+		self::TYPE_DOMAIN  => 'activitypub_site_blocked_domains',
+		self::TYPE_KEYWORD => 'activitypub_site_blocked_keywords',
 	);
 
 	/**
@@ -95,11 +110,23 @@ public static function activity_is_blocked_for_user( $activity, $user_id ) {
 	 */
 	public static function add_user_block( $user_id, $type, $value ) {
 		switch ( $type ) {
-			case 'domain':
-			case 'keyword':
+			case self::TYPE_ACTOR:
+				return Blocked_Actors::add_block( $user_id, $value );
+
+			case self::TYPE_DOMAIN:
+			case self::TYPE_KEYWORD:
 				$blocks = \get_user_meta( $user_id, self::USER_META_KEYS[ $type ], true ) ?: array(); // phpcs:ignore Universal.Operators.DisallowShortTernary.Found
 
-				if ( ! in_array( $value, $blocks, true ) ) {
+				if ( ! \in_array( $value, $blocks, true ) ) {
+					/**
+					 * Fired when a domain or keyword is blocked.
+					 *
+					 * @param string $value   The blocked domain or keyword.
+					 * @param string $type    The block type (actor, domain, keyword).
+					 * @param int    $user_id The user ID.
+					 */
+					\do_action( 'activitypub_add_user_block', $value, $type, $user_id );
+
 					$blocks[] = $value;
 					return (bool) \update_user_meta( $user_id, self::USER_META_KEYS[ $type ], $blocks );
 				}
@@ -119,14 +146,26 @@ public static function add_user_block( $user_id, $type, $value ) {
 	 */
 	public static function remove_user_block( $user_id, $type, $value ) {
 		switch ( $type ) {
-			case 'domain':
-			case 'keyword':
+			case self::TYPE_ACTOR:
+				return Blocked_Actors::remove_block( $user_id, $value );
+
+			case self::TYPE_DOMAIN:
+			case self::TYPE_KEYWORD:
 				$blocks = \get_user_meta( $user_id, self::USER_META_KEYS[ $type ], true ) ?: array(); // phpcs:ignore Universal.Operators.DisallowShortTernary.Found
-				$key    = array_search( $value, $blocks, true );
+				$key    = \array_search( $value, $blocks, true );
 
 				if ( false !== $key ) {
+					/**
+					 * Fired when a domain or keyword is unblocked.
+					 *
+					 * @param string $value   The unblocked domain or keyword.
+					 * @param string $type    The block type (actor, domain, keyword).
+					 * @param int    $user_id The user ID.
+					 */
+					\do_action( 'activitypub_remove_user_block', $value, $type, $user_id );
+
 					unset( $blocks[ $key ] );
-					return \update_user_meta( $user_id, self::USER_META_KEYS[ $type ], array_values( $blocks ) );
+					return \update_user_meta( $user_id, self::USER_META_KEYS[ $type ], \array_values( $blocks ) );
 				}
 				break;
 		}
@@ -142,9 +181,9 @@ public static function remove_user_block( $user_id, $type, $value ) {
 	 */
 	public static function get_user_blocks( $user_id ) {
 		return array(
-			'actors'   => array(),
-			'domains'  => \get_user_meta( $user_id, self::USER_META_KEYS['domain'], true ) ?: array(), // phpcs:ignore Universal.Operators.DisallowShortTernary.Found
-			'keywords' => \get_user_meta( $user_id, self::USER_META_KEYS['keyword'], true ) ?: array(), // phpcs:ignore Universal.Operators.DisallowShortTernary.Found
+			'actors'   => \wp_list_pluck( Blocked_Actors::get_blocked_actors( $user_id ), 'guid' ),
+			'domains'  => \get_user_meta( $user_id, self::USER_META_KEYS[ self::TYPE_DOMAIN ], true ) ?: array(), // phpcs:ignore Universal.Operators.DisallowShortTernary.Found
+			'keywords' => \get_user_meta( $user_id, self::USER_META_KEYS[ self::TYPE_KEYWORD ], true ) ?: array(), // phpcs:ignore Universal.Operators.DisallowShortTernary.Found
 		);
 	}
 
@@ -157,11 +196,23 @@ public static function get_user_blocks( $user_id ) {
 	 */
 	public static function add_site_block( $type, $value ) {
 		switch ( $type ) {
-			case 'domain':
-			case 'keyword':
+			case self::TYPE_ACTOR:
+				// Site-wide actor blocking uses the BLOG_USER_ID.
+				return self::add_user_block( Actors::BLOG_USER_ID, self::TYPE_ACTOR, $value );
+
+			case self::TYPE_DOMAIN:
+			case self::TYPE_KEYWORD:
 				$blocks = \get_option( self::OPTION_KEYS[ $type ], array() );
 
-				if ( ! in_array( $value, $blocks, true ) ) {
+				if ( ! \in_array( $value, $blocks, true ) ) {
+					/**
+					 * Fired when a domain or keyword is blocked site-wide.
+					 *
+					 * @param string $value The blocked domain or keyword.
+					 * @param string $type  The block type (actor, domain, keyword).
+					 */
+					\do_action( 'activitypub_add_site_block', $value, $type );
+
 					$blocks[] = $value;
 					return \update_option( self::OPTION_KEYS[ $type ], $blocks );
 				}
@@ -180,14 +231,26 @@ public static function add_site_block( $type, $value ) {
 	 */
 	public static function remove_site_block( $type, $value ) {
 		switch ( $type ) {
-			case 'domain':
-			case 'keyword':
+			case self::TYPE_ACTOR:
+				// Site-wide actor unblocking uses the BLOG_USER_ID.
+				return self::remove_user_block( Actors::BLOG_USER_ID, self::TYPE_ACTOR, $value );
+
+			case self::TYPE_DOMAIN:
+			case self::TYPE_KEYWORD:
 				$blocks = \get_option( self::OPTION_KEYS[ $type ], array() );
-				$key    = array_search( $value, $blocks, true );
+				$key    = \array_search( $value, $blocks, true );
 
 				if ( false !== $key ) {
+					/**
+					 * Fired when a domain or keyword is unblocked site-wide.
+					 *
+					 * @param string $value The unblocked domain or keyword.
+					 * @param string $type  The block type (actor, domain, keyword).
+					 */
+					\do_action( 'activitypub_remove_site_block', $value, $type );
+
 					unset( $blocks[ $key ] );
-					return \update_option( self::OPTION_KEYS[ $type ], array_values( $blocks ) );
+					return \update_option( self::OPTION_KEYS[ $type ], \array_values( $blocks ) );
 				}
 				break;
 		}
@@ -202,9 +265,9 @@ public static function remove_site_block( $type, $value ) {
 	 */
 	public static function get_site_blocks() {
 		return array(
-			'actors'   => array(),
-			'domains'  => \get_option( self::OPTION_KEYS['domain'], array() ),
-			'keywords' => \get_option( self::OPTION_KEYS['keyword'], array() ),
+			'actors'   => \wp_list_pluck( Blocked_Actors::get_blocked_actors( Actors::BLOG_USER_ID ), 'guid' ),
+			'domains'  => \get_option( self::OPTION_KEYS[ self::TYPE_DOMAIN ], array() ),
+			'keywords' => \get_option( self::OPTION_KEYS[ self::TYPE_KEYWORD ], array() ),
 		);
 	}
 
@@ -224,8 +287,18 @@ private static function check_activity_against_blocks( $activity, $blocked_actor
 		$actor_id = object_to_uri( $activity->get_actor() );
 
 		// Check blocked actors.
-		if ( $actor_id && \in_array( $actor_id, $blocked_actors, true ) ) {
-			return true;
+		if ( $actor_id ) {
+			// If actor_id is not a URL, resolve it via webfinger.
+			if ( ! \str_starts_with( $actor_id, 'http' ) ) {
+				$resolved_url = Webfinger::resolve( $actor_id );
+				if ( ! \is_wp_error( $resolved_url ) ) {
+					$actor_id = $resolved_url;
+				}
+			}
+
+			if ( \in_array( $actor_id, $blocked_actors, true ) ) {
+				return true;
+			}
 		}
 
 		// Check blocked domains.

includes/collection/class-blocked-actors.php

@@ -0,0 +1,138 @@
+<?php
+/**
+ * Blocked Actors collection file.
+ *
+ * @package Activitypub
+ */
+
+namespace Activitypub\Collection;
+
+use Activitypub\Moderation;
+
+/**
+ * ActivityPub Blocked Actors Collection.
+ */
+class Blocked_Actors {
+
+	/**
+	 * Add an actor block for a user.
+	 *
+	 * @param int    $user_id The user ID.
+	 * @param string $value   The actor URI to block.
+	 * @return bool True on success, false on failure.
+	 */
+	public static function add_block( $user_id, $value ) {
+		// Find or create actor post.
+		$actor_post = Actors::fetch_remote_by_uri( $value );
+		if ( \is_wp_error( $actor_post ) ) {
+			return false;
+		}
+
+		$blocked = \get_post_meta( $actor_post->ID, Moderation::BLOCKED_ACTORS_META_KEY, false );
+		if ( ! \in_array( (string) $user_id, $blocked, true ) ) {
+			/**
+			 * Fired when an actor is blocked.
+			 *
+			 * @param string $value   The blocked actor URI.
+			 * @param string $type    The block type (actor, domain, keyword).
+			 * @param int    $user_id The user ID.
+			 */
+			\do_action( 'activitypub_add_user_block', $value, Moderation::TYPE_ACTOR, $user_id );
+
+			$result = (bool) \add_post_meta( $actor_post->ID, Moderation::BLOCKED_ACTORS_META_KEY, (string) $user_id );
+			\clean_post_cache( $actor_post->ID );
+
+			return $result;
+		}
+
+		return true; // Already blocked.
+	}
+
+	/**
+	 * Remove an actor block for a user.
+	 *
+	 * @param int        $user_id The user ID.
+	 * @param string|int $value   The actor URI or post ID to unblock.
+	 * @return bool True on success, false on failure.
+	 */
+	public static function remove_block( $user_id, $value ) {
+		// Handle both post ID and URI formats.
+		if ( \is_numeric( $value ) ) {
+			$post_id = (int) $value;
+		} else {
+			// Otherwise, find the actor post by actor ID.
+			$actor_post = Actors::fetch_remote_by_uri( $value );
+			if ( \is_wp_error( $actor_post ) ) {
+				return false;
+			}
+			$post_id = $actor_post->ID;
+		}
+
+		/**
+		 * Fired when an actor is unblocked.
+		 *
+		 * @param string $value   The unblocked actor URI.
+		 * @param string $type    The block type (actor, domain, keyword).
+		 * @param int    $user_id The user ID.
+		 */
+		\do_action( 'activitypub_remove_user_block', $value, Moderation::TYPE_ACTOR, $user_id );
+
+		$result = \delete_post_meta( $post_id, Moderation::BLOCKED_ACTORS_META_KEY, $user_id );
+		\clean_post_cache( $post_id );
+
+		return $result;
+	}
+
+	/**
+	 * Get the blocked actors of a given user, along with a total count for pagination purposes.
+	 *
+	 * @param int|null $user_id The ID of the WordPress User.
+	 * @param int      $number  Maximum number of results to return.
+	 * @param int      $page    Page number.
+	 * @param array    $args    The WP_Query arguments.
+	 *
+	 * @return array {
+	 *      Data about the blocked actors.
+	 *
+	 *      @type \WP_Post[] $blocked_actors List of blocked Actor WP_Post objects.
+	 *      @type int        $total         Total number of blocked actors.
+	 *  }
+	 */
+	public static function get_blocked_actors_with_count( $user_id, $number = -1, $page = null, $args = array() ) {
+		$defaults = array(
+			'post_type'      => Actors::POST_TYPE,
+			'posts_per_page' => $number,
+			'paged'          => $page,
+			'orderby'        => 'ID',
+			'order'          => 'DESC',
+			// phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
+			'meta_query'     => array(
+				array(
+					'key'   => Moderation::BLOCKED_ACTORS_META_KEY,
+					'value' => $user_id,
+				),
+			),
+		);
+
+		$args           = \wp_parse_args( $args, $defaults );
+		$query          = new \WP_Query( $args );
+		$total          = $query->found_posts;
+		$blocked_actors = \array_filter( $query->posts );
+
+		return \compact( 'blocked_actors', 'total' );
+	}
+
+	/**
+	 * Get the blocked actors of a given user.
+	 *
+	 * @param int|null $user_id The ID of the WordPress User.
+	 * @param int      $number  Maximum number of results to return.
+	 * @param int      $page    Page number.
+	 * @param array    $args    The WP_Query arguments.
+	 *
+	 * @return \WP_Post[] List of blocked Actors.
+	 */
+	public static function get_blocked_actors( $user_id, $number = -1, $page = null, $args = array() ) {
+		return self::get_blocked_actors_with_count( $user_id, $number, $page, $args )['blocked_actors'];
+	}
+}