Notifications for anonymous users on nodes I am looking for a module or some kind of workaround e.g. involving Rules, that will allow anonymous users to subscribe to new comments on nodes they have created. My user scenario is as follows:


An anonymous user wants to post a new forum topic 
She clicks on the “Add new forum topic” button
On the URL node/add/forumtopic she is presented by the usual form
On the form there is an email field with a check box underneath with the label “I would like to receive an email when comments are posted to my thread”
She types in her email and marks the checkbox - yes, she would like to have email notifications
She submits the form and when a comment is posted in her thread, she
gets a notification email with a link to the comment and a link that
allows her to unsubscribe from the thread.


I have looked at this nice writeup on groups.drupal.org where different notification modules are compared, but none seems to be offering the functionality I am looking for.

I have installed Comment Notify that offers the desired functionality - but only on comments, not on nodes.

I have tried installing Watcher, but it is early in development and still seems pretty buggy.

This seems to me like a very common scenario - what would be the recommended way of implementing this feature? Any help is very appreciated.
I would probably solve this with the following Rules-based setup:

1) Create a custom entity for anonymous posters with only a text field for email and an entity reference field for the node they created. Here's a pretty good writeup on creating custom entities: 
http://www.istos.it/blog/drupal-entities/drupal-entities-part-3-programming-hello-drupal-entity

And here's Drupal.org: http://drupal.org/node/1026420

2) Create a rule for "Node->After saving new content" that checks if the poster was anonymous and if so, creates a new anonymous posters entity with the user's email + reference to the created node.

3) Create a rule for "Comment->After saving a new comment" that does a "Fetch entity by property" action and after a anonymous poster entity, sends an email out to them.

The only trick you need to figure out is how to play with rules upon fetching entities and accessing their fields. You need to create some rules component so achieve this whole flow since in order to access the field in the entity, you need to verify the type of the entity and this happens in "conditions", which can't be done after "actions" which is where the "fetch entity by property" magic happens.

So you'll basically have to create a Rules Component that does what needs to be done with the fetched entity.

This is definitely not the only way to achieve what you need to accomplish, but since I'm a strong believer in the endless powers of Rules, I like solving things with it. :)