Following v1: Follow Dialogue (#1930)

Co-authored-by: Konstantin Obenland <[email protected]>

Author: pfefferle

.github/changelog/1930-from-description

@@ -0,0 +1,4 @@
+Significance: minor
+Type: added
+
+Added a first version of the Follow form, allowing users to follow other Actors by username or profile link.

assets/css/activitypub-admin.css

@@ -359,6 +359,25 @@ input.blog-user-identifier {
 	padding: 16px 20px;
 }
 
+#activitypub-follow-form .highlight {
+	animation: highlight-fade 3s ease-in-out;
+	border-color: #3582c4 !important;
+	box-shadow: 0 0 0 1px #3582c4;
+}
+
+@keyframes highlight-fade {
+	0% {
+		background-color: #e7f3ff;
+		border-color: #3582c4;
+		box-shadow: 0 0 0 1px #3582c4;
+	}
+	100% {
+		background-color: #fff;
+		border-color: #8c8f94;
+		box-shadow: none;
+	}
+}
+
 @media screen and (max-width: 782px) {
 	.activitypub-settings {
 		margin: 0 22px;

includes/class-sanitize.php

@@ -123,4 +123,18 @@ public static function constant_value( $value ) {
 
 		return $value;
 	}
+
+	/**
+	 * Sanitize a webfinger identifier.
+	 *
+	 * @param string $value The value to sanitize.
+	 *
+	 * @return string The sanitized webfinger identifier.
+	 */
+	public static function webfinger( $value ) {
+		$value = \str_replace( 'acct:', '', $value );
+		$value = \trim( $value, '@' );
+
+		return $value;
+	}
 }

includes/class-webfinger.php

@@ -297,4 +297,16 @@ public static function generate_cache_key( $uri ) {
 
 		return 'webfinger_' . md5( $uri );
 	}
+
+	/**
+	 * Infer a shortname from the Actor ID or URL. Used only for fallbacks,
+	 * we will try to use what's supplied.
+	 *
+	 * @param string $uri The URI.
+	 *
+	 * @return string Hopefully the name of the Follower.
+	 */
+	public static function guess( $uri ) {
+		return extract_name_from_uri( $uri ) . '@' . \wp_parse_url( $uri, PHP_URL_HOST );
+	}
 }

includes/collection/class-followers.php

@@ -84,9 +84,9 @@ public static function remove( $post_id, $user_id ) {
 		/**
 		 * Fires before a Follower is removed.
 		 *
-		 * @param \WP_Post                  $post    The remote Actor object.
-		 * @param int                       $user_id The ID of the WordPress User.
-		 * @param \Activitypub\Actors\Actor $actor   The Actor object.
+		 * @param \WP_Post                    $post    The remote Actor object.
+		 * @param int                         $user_id The ID of the WordPress User.
+		 * @param \Activitypub\Activity\Actor $actor   The remote Actor object.
 		 */
 		\do_action( 'activitypub_followers_pre_remove_follower', $post, $user_id, Actors::get_actor( $post ) );
 
@@ -436,4 +436,19 @@ public static function clear_errors( $post_id ) {
 
 		return Actors::clear_errors( $post_id );
 	}
+
+	/**
+	 * Check the status of a given following.
+	 *
+	 * @param int $post_id The ID of the Post.
+	 * @param int $user_id The ID of the WordPress User.
+	 *
+	 * @return bool The status of the following.
+	 */
+	public static function follows( $post_id, $user_id ) {
+		$all_meta  = \get_post_meta( $post_id );
+		$following = $all_meta[ self::FOLLOWER_META_KEY ] ?? array();
+
+		return \in_array( (string) $user_id, $following, true );
+	}
 }

includes/table/class-followers.php

@@ -9,6 +9,9 @@
 
 use Activitypub\Collection\Actors;
 use Activitypub\Collection\Followers as Follower_Collection;
+use Activitypub\Collection\Following;
+use Activitypub\Sanitize;
+use Activitypub\Webfinger;
 
 use function Activitypub\object_to_uri;
 
@@ -27,14 +30,23 @@ class Followers extends \WP_List_Table {
 	 */
 	private $user_id;
 
+	/**
+	 * Follow URL.
+	 *
+	 * @var string
+	 */
+	public $follow_url;
+
 	/**
 	 * Constructor.
 	 */
 	public function __construct() {
 		if ( get_current_screen()->id === 'settings_page_activitypub' ) {
-			$this->user_id = Actors::BLOG_USER_ID;
+			$this->user_id    = Actors::BLOG_USER_ID;
+			$this->follow_url = \admin_url( 'options-general.php?page=activitypub&tab=following' );
 		} else {
-			$this->user_id = \get_current_user_id();
+			$this->user_id    = \get_current_user_id();
+			$this->follow_url = \admin_url( 'users.php?page=activitypub-following' );
 
 			\add_action( 'admin_notices', array( $this, 'process_admin_notices' ) );
 		}
@@ -132,6 +144,7 @@ public function get_columns() {
 			'cb'         => '<input type="checkbox" />',
 			'username'   => \esc_html__( 'Username', 'activitypub' ),
 			'post_title' => \esc_html__( 'Name', 'activitypub' ),
+			'webfinger'  => \esc_html__( 'Profile', 'activitypub' ),
 			'modified'   => \esc_html__( 'Last updated', 'activitypub' ),
 		);
 	}
@@ -192,13 +205,21 @@ public function prepare_items() {
 		);
 
 		foreach ( $followers as $follower ) {
-			$actor         = Actors::get_actor( $follower );
+			$actor     = Actors::get_actor( $follower );
+			$url       = object_to_uri( $actor->get_url() ?? $actor->get_id() );
+			$webfinger = Webfinger::uri_to_acct( $url );
+
+			if ( is_wp_error( $webfinger ) ) {
+				$webfinger = Webfinger::guess( $url );
+			}
+
 			$this->items[] = array(
 				'id'         => $follower->ID,
 				'icon'       => $actor->get_icon()['url'] ?? '',
-				'post_title' => $actor->get_name(),
+				'post_title' => $actor->get_name() ?? $actor->get_preferred_username(),
 				'username'   => $actor->get_preferred_username(),
-				'url'        => object_to_uri( $actor->get_url() ),
+				'url'        => $url,
+				'webfinger'  => $webfinger,
 				'identifier' => $actor->get_id(),
 				'modified'   => $follower->post_modified_gmt,
 			);
@@ -283,14 +304,30 @@ public function column_cb( $item ) {
 	 */
 	public function column_username( $item ) {
 		return \sprintf(
-			'<img src="%1$s" width="32" height="32" alt="%2$s" loading="lazy"/> <strong><a href="%3$s">%4$s</a></strong><br />',
+			'<img src="%1$s" width="32" height="32" alt="%2$s" loading="lazy"/> <strong><a href="%3$s" target="_blank">%4$s</a></strong><br />',
 			\esc_url( $item['icon'] ),
 			\esc_attr( $item['username'] ),
 			\esc_url( $item['url'] ),
 			\esc_html( $item['username'] )
 		);
 	}
 
+	/**
+	 * Column webfinger.
+	 *
+	 * @param array $item Item.
+	 * @return string
+	 */
+	public function column_webfinger( $item ) {
+		$webfinger = Sanitize::webfinger( $item['webfinger'] );
+
+		return \sprintf(
+			'<a href="%1$s" target="_blank" title="%1$s">@%2$s</a>',
+			\esc_url( $item['url'] ),
+			\esc_html( $webfinger )
+		);
+	}
+
 	/**
 	 * Column modified.
 	 *
@@ -310,7 +347,24 @@ public function column_modified( $item ) {
 	 * Message to be displayed when there are no followers.
 	 */
 	public function no_items() {
-		\esc_html_e( 'No followers found.', 'activitypub' );
+		// phpcs:ignore WordPress.Security.NonceVerification.Recommended
+		$search         = \sanitize_text_field( \wp_unslash( $_GET['s'] ?? '' ) );
+		$actor_or_false = $this->_is_followable( $search );
+
+		if ( $actor_or_false ) {
+			\printf(
+				/* translators: %s: Actor name. */
+				\esc_html__( '%1$s is not following you, would you like to %2$s instead?', 'activitypub' ),
+				\esc_html( $actor_or_false->post_title ),
+				\sprintf(
+					'<a href="%s">%s</a>',
+					\esc_url( \add_query_arg( 'resource', $search, $this->follow_url ) ),
+					\esc_html__( 'follow them', 'activitypub' )
+				)
+			);
+		} else {
+			\esc_html_e( 'No followers found.', 'activitypub' );
+		}
 	}
 
 	/**
@@ -346,4 +400,39 @@ protected function handle_row_actions( $item, $column_name, $primary ) {
 
 		return $this->row_actions( $actions );
 	}
+
+	/**
+	 * Checks if the searched actor can be followed.
+	 *
+	 * @param string $search The search string.
+	 *
+	 * @return \WP_Post|false The actor post or false.
+	 */
+	private function _is_followable( $search ) { // phpcs:ignore
+		if ( empty( $search ) ) {
+			return false;
+		}
+
+		$search = Sanitize::webfinger( $search );
+		if ( ! \filter_var( $search, FILTER_VALIDATE_EMAIL ) ) {
+			return false;
+		}
+
+		$search = Webfinger::resolve( $search );
+		if ( \is_wp_error( $search ) || ! \filter_var( $search, FILTER_VALIDATE_URL ) ) {
+			return false;
+		}
+
+		$actor = Actors::fetch_remote_by_uri( $search );
+		if ( \is_wp_error( $actor ) ) {
+			return false;
+		}
+
+		$does_follow = Following::check_status( $this->user_id, $actor->ID );
+		if ( $does_follow ) {
+			return false;
+		}
+
+		return $actor;
+	}
 }