Add QuoteRequest activity handler support (#2240)

Author: pfefferle

.github/changelog/2240-from-description

@@ -0,0 +1,4 @@
+Significance: minor
+Type: added
+
+Added support for QuoteRequest activities (FEP-044f), enabling proper handling, validation, and policy-based acceptance or rejection of quote requests.

FEDERATION.md

@@ -21,6 +21,7 @@ The WordPress plugin largely follows ActivityPub's server-to-server specificatio
 - [FEP-b2b8: Long-form Text](https://codeberg.org/fediverse/fep/src/branch/main/fep/b2b8/fep-b2b8.md)
 - [FEP-7888: Demystifying the context property](https://codeberg.org/fediverse/fep/src/branch/main/fep/7888/fep-7888.md)
 - [FEP-844e: Capability discovery](https://codeberg.org/fediverse/fep/src/branch/main/fep/844e/fep-844e.md)
+- [FEP-044f: Consent-respecting quote posts](https://codeberg.org/fediverse/fep/src/branch/main/fep/044f/fep-044f.md)
 
 Partially supported FEPs
 

includes/activity/class-activity.php

@@ -22,6 +22,10 @@
 class Activity extends Base_Object {
 	const JSON_LD_CONTEXT = array(
 		'https://www.w3.org/ns/activitystreams',
+		array(
+			'toot'         => 'http://joinmastodon.org/ns#',
+			'QuoteRequest' => 'toot:QuoteRequest',
+		),
 	);
 
 	/**
@@ -50,6 +54,7 @@ class Activity extends Base_Object {
 		'Listen',
 		'Move',
 		'Offer',
+		'QuoteRequest', // @see https://codeberg.org/fediverse/fep/src/branch/main/fep/044f/fep-044f.md
 		'Read',
 		'Reject',
 		'Remove',

includes/activity/class-generic-object.php

@@ -39,6 +39,7 @@
  * @method string|string[]|null          get_origin()             Gets the origin property of the object.
  * @method string|null                   get_preferred_username() Gets the preferred username of the object.
  * @method string|null                   get_published()          Gets the date and time the object was published in ISO 8601 format.
+ * @method string|null                   get_result()             Gets the result property of the object.
  * @method bool|null                     get_sensitive()          Gets the sensitive property of the object.
  * @method string|null                   get_summary()            Gets the natural language summary of the object.
  * @method string[]|null                 get_summary_map()        Gets the summary map property of the object.
@@ -70,6 +71,7 @@
  * @method Base_Object set_object( string|array|Base_Object|null $data ) Sets the direct object of the activity.
  * @method Base_Object set_origin( string|array|null $origin )           Sets the origin property of the object.
  * @method Base_Object set_published( string|null $published )           Sets the date and time the object was published in ISO 8601 format.
+ * @method Base_Object set_result( string|null $result )                 Sets the result property of the object.
  * @method Base_Object set_sensitive( bool|null $sensitive )             Sets the sensitive property of the object.
  * @method Base_Object set_summary( string $summary )                    Sets the natural language summary of the object.
  * @method Base_Object set_summary_map( array|null $summary_map )        Sets the summary property of the object.

includes/activity/extended-object/class-quote-authorization.php

@@ -0,0 +1,70 @@
+<?php
+/**
+ * Quote_Authorization is an implementation of the QuoteAuthorization activity type,
+ * as defined in FEP-044f (https://codeberg.org/fediverse/fep/src/branch/main/fep/044f/fep-044f.md#quoteauthorization).
+ *
+ * This class represents a QuoteAuthorization activity for ActivityPub implementations.
+ *
+ * @package Activitypub
+ */
+
+namespace Activitypub\Activity\Extended_Object;
+
+use Activitypub\Activity\Base_Object;
+
+/**
+ * Class representing a QuoteAuthorization activity.
+ *
+ * @see https://codeberg.org/fediverse/fep/src/branch/main/fep/044f/fep-044f.md#quoteauthorization
+ *
+ * @since unreleased
+ *
+ * @method Base_Object|string|array|null get_interacting_object() Gets the interacting object property of the object.
+ * @method Base_Object|string|array|null get_interaction_target() Gets the interaction target property of the object.
+ *
+ * @method Quote_Authorization set_interacting_object( string|array|Base_Object|null $data ) Sets the interacting object property of the object.
+ * @method Quote_Authorization set_interaction_target( string|array|Base_Object|null $data ) Sets the interaction target property of the object.
+ */
+class Quote_Authorization extends Base_Object {
+	/**
+	 * The JSON-LD context for the object.
+	 *
+	 * @var array
+	 */
+	const JSON_LD_CONTEXT = array(
+		'https://www.w3.org/ns/activitystreams',
+		array(
+			'QuoteAuthorization' => 'https://w3id.org/fep/044f#QuoteAuthorization',
+			'gts'                => 'https://gotosocial.org/ns#',
+			'interactingObject'  => array(
+				'@id'   => 'gts:interactingObject',
+				'@type' => '@id',
+			),
+			'interactionTarget'  => array(
+				'@id'   => 'gts:interactionTarget',
+				'@type' => '@id',
+			),
+		),
+	);
+
+	/**
+	 * The type of the object.
+	 *
+	 * @var string
+	 */
+	protected $type = 'QuoteAuthorization';
+
+	/**
+	 * The object that is being interacted with.
+	 *
+	 * @var Base_Object|string|array|null
+	 */
+	protected $interacting_object;
+
+	/**
+	 * The target of the interaction.
+	 *
+	 * @var Base_Object|string|array|null
+	 */
+	protected $interaction_target;
+}

includes/class-comment.php

@@ -473,7 +473,7 @@ public static function generate_id( $comment ) {
 		}
 
 		// Generate URI based on comment ID.
-		return \add_query_arg( 'c', $comment->comment_ID, \trailingslashit( \home_url() ) );
+		return \add_query_arg( 'c', $comment->comment_ID, \home_url( '/' ) );
 	}
 
 	/**

includes/class-handler.php

@@ -15,6 +15,7 @@
 use Activitypub\Handler\Inbox;
 use Activitypub\Handler\Like;
 use Activitypub\Handler\Move;
+use Activitypub\Handler\Quote_Request;
 use Activitypub\Handler\Reject;
 use Activitypub\Handler\Undo;
 use Activitypub\Handler\Update;
@@ -42,6 +43,7 @@ public static function register_handlers() {
 		Inbox::init();
 		Like::init();
 		Move::init();
+		Quote_Request::init();
 		Reject::init();
 		Undo::init();
 		Update::init();

includes/class-query.php

@@ -7,6 +7,7 @@
 
 namespace Activitypub;
 
+use Activitypub\Activity\Extended_Object\Quote_Authorization;
 use Activitypub\Collection\Actors;
 use Activitypub\Collection\Outbox;
 use Activitypub\Transformer\Factory;
@@ -138,6 +139,10 @@ public function get_activitypub_object_id() {
 	private function prepare_activitypub_data() {
 		$queried_object = $this->get_queried_object();
 
+		if ( $queried_object instanceof \WP_Post && \get_query_var( 'stamp' ) ) {
+			return $this->maybe_get_stamp();
+		}
+
 		// Check for Outbox Activity.
 		if (
 			$queried_object instanceof \WP_Post &&
@@ -311,7 +316,7 @@ public function is_activitypub_request() {
 	 */
 	public function should_negotiate_content() {
 		$return           = false;
-		$always_negotiate = array( 'p', 'c', 'author', 'actor', 'preview', 'activitypub' );
+		$always_negotiate = array( 'p', 'c', 'author', 'actor', 'stamp', 'preview', 'activitypub' );
 		$url              = \wp_parse_url( $this->get_request_url(), PHP_URL_QUERY );
 		$query            = array();
 		\wp_parse_str( $url, $query );
@@ -368,4 +373,46 @@ public function is_old_host_request() {
 	public function set_old_host_request( $state = true ) {
 		$this->is_old_host_request = $state;
 	}
+
+	/**
+	 * Maybe get a QuoteAuthorization object from a stamp.
+	 *
+	 * @return bool True if the object was prepared, false otherwise.
+	 */
+	private function maybe_get_stamp() {
+		require_once ABSPATH . 'wp-admin/includes/post.php';
+
+		$stamp = \get_query_var( 'stamp' );
+		$meta  = \get_post_meta_by_id( (int) $stamp );
+
+		if ( ! $meta ) {
+			return false;
+		}
+
+		$post     = $this->get_queried_object();
+		$user_uri = get_user_id( $post->post_author );
+
+		if ( ! $user_uri ) {
+			return false;
+		}
+
+		$stamp_uri = \add_query_arg(
+			array(
+				'p'     => $post->ID,
+				'stamp' => $meta->meta_id,
+			),
+			\home_url( '/' )
+		);
+
+		$activitypub_object = new Quote_Authorization();
+		$activitypub_object->set_id( $stamp_uri );
+		$activitypub_object->set_attributed_to( $user_uri );
+		$activitypub_object->set_interacting_object( $meta->meta_value );
+		$activitypub_object->set_interaction_target( get_post_id( $post->ID ) );
+
+		$this->activitypub_object    = $activitypub_object;
+		$this->activitypub_object_id = $activitypub_object->get_id();
+
+		return true;
+	}
 }

includes/class-router.php

@@ -199,6 +199,7 @@ public static function redirect_canonical( $redirect_url, $requested_url ) {
 
 		$query_params = \wp_parse_args( $query );
 		unset( $query_params['activitypub'] );
+		unset( $query_params['stamp'] );
 
 		if ( 1 !== count( $query_params ) ) {
 			return $redirect_url;
@@ -273,6 +274,7 @@ public static function add_query_vars( $vars ) {
 		$vars[] = 'preview';
 		$vars[] = 'author';
 		$vars[] = 'actor';
+		$vars[] = 'stamp';
 		$vars[] = 'type';
 		$vars[] = 'c';
 		$vars[] = 'p';

includes/functions.php

@@ -1334,14 +1334,15 @@ function get_user_id( $id ) {
  * @return string The ActivityPub ID (a URL) of the Post.
  */
 function get_post_id( $id ) {
-	$post = get_post( $id );
+	$last_legacy_id = (int) \get_option( 'activitypub_last_post_with_permalink_as_id', 0 );
+	$post_id        = (int) $id;
 
-	if ( ! $post ) {
-		return false;
+	if ( $post_id > $last_legacy_id ) {
+		// Generate URI based on post ID.
+		return \add_query_arg( 'p', $post_id, \home_url( '/' ) );
 	}
 
-	$transformer = new Post( $post );
-	return $transformer->get_id();
+	return \get_permalink( $post_id );
 }
 
 /**