Using Helpers inside a Controller

If I am understanding you correctly, that means you want your AJAX request to return HTML markup instead of data, right? If so, you should really use a view component like a partial, which can itself use helpers just fine. In the second edition of Agile Web Development With Rails, Chapter 9 ("Task D: Add a Dash of AJAX") has an example of this technique.

Controllers should be about executing business logic and providing data to the view, not being the view themselves. Helpers are *view* helpers not *controller* helpers.

Craig McClanahan