Add "Message-ID" email header to outgoing reply-by-emails.

This will allow proper email threading to occur in email clients that support it. To prepare the "Message-ID" header, a new listener property - "reply_to_id" - is added to determine the uniqueness of the outgoing email. The "reply_to_id" is generally the post ID of whatever is creating the email. See #49.
r-a-y · Jun 12, 2014 · bce67d5 · bce67d5
1 parent 6b5a1b9
commit bce67d5
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Showing 2 changed files with 30 additions and 6 deletions.
diff --git a/bp-rbe-core.php b/bp-rbe-core.php
@@ -280,6 +280,17 @@ public function wp_mail_filter( $args ) {
 				// Don't like this? there's a filter for that!
 				$querystring = apply_filters( 'bp_rbe_encode_querystring', bp_rbe_encode( array( 'string' => $querystring ) ), $querystring );
 
+				// Set the 'Message-Id' header
+				// This is used to enable message threading in email clients
+				if ( ! empty( $listener->reply_to_id ) ) {
+					$reply_to_id = $listener->reply_to_id;
+				} elseif ( ! empty( $listener->secondary_item_id ) ) {
+					$reply_to_id = $listener->secondary_item_id;
+				} else {
+					$reply_to_id = $listener->item_id;
+				}
+				$args['headers'] .= 'Message-ID: <' . md5( $querystring . $reply_to_id ) . '@' . esc_url( $_SERVER['SERVER_NAME'] ) . '>' . PHP_EOL;
+
 				// Inject the querystring into the email address
 				$args['headers'] .= 'Reply-To: ' . bp_rbe_inject_qs_in_email( $querystring ) . PHP_EOL;
 
@@ -349,6 +360,11 @@ public function activity_listener( $item ) {
 				break;
 		}
 
+		// reply-to id fallback
+		if ( empty( $this->listener->reply_to_id ) ) {
+			$this->listener->reply_to_id = ! empty( $this->listener->secondary_item_id ) ? $this->listener->secondary_item_id : $this->listener->item_id;
+		}
+
 	}
 
 	/**
@@ -389,6 +405,9 @@ public function group_forum_listener( $post_id ) {
 		// @see BP_Reply_By_Email::get_temporary_variables()
 		// @see BP_Reply_By_Email::set_group_id()
 		$this->listener->secondary_item_id = bp_get_current_group_id();
+
+		// reply-to ID
+		$this->listener->reply_to_id = $post_id;
 	}
 
 	/**
@@ -403,9 +422,10 @@ public function message_listener( $item ) {
 
 		$this->listener = new stdClass;
 
-		$this->listener->component = $bp->messages->id;
-		$this->listener->item_id   = $item->thread_id;
-		$this->listener->user_id   = $item->sender_id;
+		$this->listener->component   = $bp->messages->id;
+		$this->listener->item_id     = $item->thread_id;
+		$this->listener->user_id     = $item->sender_id;
+		$this->listener->reply_to_id = $item->id;
 	}
 
 	/**
@@ -427,8 +447,9 @@ public function message_listener( $item ) {
 	public function bbp_listener( $reply_id, $topic_id ) {
 		$this->listener = new stdClass;
 
-		$this->listener->component = 'bbpress';
-		$this->listener->item_id   = $topic_id;
+		$this->listener->component   = 'bbpress';
+		$this->listener->item_id     = $topic_id;
+		$this->listener->reply_to_id = $reply_id;
 	}
 
 	/**
@@ -687,4 +708,4 @@ public function disable_non_rbe_notice( $retval, $args ) {
 
 		return $retval;
 	}
-}
+}
diff --git a/includes/bp-rbe-extend-bbpress.php b/includes/bp-rbe-extend-bbpress.php
@@ -121,6 +121,9 @@ public function extend_activity_listener( $listener, $item ) {
 		// setup our secondary item ID, which is the topic ID
 		$listener->secondary_item_id = $item->secondary_item_id;
 
+		// setup reply-to ID, which is the post ID
+		$listener->reply_to_id = $item->secondary_item_id;
+
 		// if activity type is a bbPress reply, we need to grab the topic ID manually
 		if ( $item->type == $this->activity_type ) {
 			global $bp;