How do you handle Rail's flash with Ajax requests?

Question

I'm pretty happy with the solution that I came up with. Basically, I have a helper method that reloads the flash inline, and then I have an after_filter that clear out the flash if the request is xhr. Does anyone have a simpler solution than that?

Update: The solution above was written back in Rails 1.x and is no longer supported.

Answer 1

You can also store the flash messages in the response headers using a after_filter block and display them using javascript:

class ApplicationController < ActionController::Base
after_filter :flash_to_headers

def flash_to_headers
  return unless request.xhr?
  response.headers['X-Message'] = flash[:error]  unless flash[:error].blank?
  # repeat for other flash types...

  flash.discard  # don't want the flash to appear when you reload page
end

And in application.js add a global ajax handler. For jquery do something like this:

$(document).ajaxError(function(event, request) {
  var msg = request.getResponseHeader('X-Message');
  if (msg) alert(msg);
});

Replace alert() with your own javascript flash function or try jGrowl.