Confiforms: Apply filter to a user field

[its moi]

Is it possible to have a filter on a user field so that only certain users can be selected from the complete user data? If so, how? 

I have a form with a user field where I just want to have a few users to be selected from the complete pool (8,000 users). I can think of some work arounds like using a dropdown with these users and then setting the selected user in a separate user field, but maybe it is easier with using rules for field definitions and applying a filter on my user field, but I do not get this to work. 

Any hint appreciated :) Thanks  

[Alex Medved _ConfiForms_ · Accepted solution]

Hi

Sorry, you cannot apply the filter on the field that really has no registered options.

User fields are lookups to user directory and the field itself does not have any options/choices you can filter on

The easiest way would be to create a dropdown of users, where the ID of the dropdown choice is a user name. This way you really dont need to copy anything anywhere, as you can always transform a username to user object (via "asUser" virtual function) and access any user's object properties if and when necessary

Alex

[its moi]

Ok nice. But I am using the selected user as a recipient for an IFTTT send email. Can I also refer to a dropdown as stated above in the recipients field of that IFTTT send mail action? 

[Alex Medved _ConfiForms_]

Sure, as long as it holds a valid username we can either lookup the user object or use "username" directly as a recipient address (ConfiForms can lookup user's email in case if a username was given as parameter for recipient field)