rails 3 - controller respond with javascript even through request format was text/html

Question

I have a simple scenario where I want to request a page. The request format is text/html. If there is some error in the controller/action logic for that request, I want to get an error message. The twist is that I want this error message to be communicated to be with a javascript response type (ie no page refresh). If there are no errors, then I want the page to be loaded via the expected text/html response type.

Basically, I want two different response types depending on whether there is an error or not. Is this doable in rails 3? If so, what is best practice?

A quick code sample would be much appreciated.

Thanks.

Answer 1

Sure it's doable!

I would do it like this:

def some_action
  # code
  # more code
  # implicit or explicit rendering of an html template
rescue Exception => ex
  render :json => ex.to_json, 
         :content_type => 'application/json',
         :layout => false
end