Notify gallery photo owner when comment added

Joomla! 3.10.9
MariaDB 10.3.34
CB 2.7.2+build.2022.05.09.18.01.50.cff9cffac

A few months ago you advised me how to set up CB Gallery in a GroupJive group, and disallow it in Profiles. This allowed my club members to upload photos only to a specific gallery and other members to comment/critique them. This is working well - thank you.
I have now been asked to see if we could email the owner of a photo when a new comment is added by another member. I can set up an email Auto Action based on trigger "activity_onAfterCreateComment" and this works, but obviously using "[userid]" or "[mail]" in the "to" field sends the email to the triggering user. I do not know how to get the email or userid of the member whose photo has been commented on. Ideally I would also like to include the title of the photo in the text of the email.
Could you advise me if this is possible, and how to proceed please. I am not familiar with assets and variables, so if these are required could you explain in as simple a fashion as possible - thanks in advance.

Make a copy of the "CB Gallery - Comment Notification" system action and change its Type to Email. Next set To to [var2_user_id] and that should email the person that owns the gallery entry. To get the user id of the user making the comment you'd use [var3_user_id]. You can then use our nested substitution feature to get more information like their name such as in the following example.

[cb:userfield field="formatname" user="[var3_user_id]" /]

Excellent - thanks for your quick reply. That works fine.

As previously mentioned I have no experience with modern coding systems (retired from mainframe programming 30 years ago), and i appreciate you cannot train all your customers, so forgive the next question.
From your trigger document I can see that "activity_onAfterCreateStreamComment" takes 3 parameters, the second of which (var2?) appears to be the user being viewed, and the third (var3?) appears to be the result which seems to be database row in "...comprofiler_plugin_activity_comments". Is there a way of rerieving the title of the item commented on other than extracting the item id from the asset, and then querying the gallery_items table?

You can access variables directly using substitutions. So for example if var2 is a user object then [var2_username] would return their username. For activity_onAfterCreateStreamComment specifically though the variables are as follows.


var1 is the comment stream object. var2 is the source object of the comment (in this case it will be the gallery media object), and var3 is the actual comment object. So if you want the title you'd use [var2_title].

That's excellent - thanks very much for your help