flash.rb

# May not be the best approach
# Issues with Proxies limititing headers
# Headers could be cached
# Not sure of having JSON


class ApplicationController < ActionController::Base
  after_filter :flash_to_headers

  def flash_to_headers
    return unless request.xhr?
    unless flash.empty?
      response.headers['X-Flash'] = flash.to_json
    end
    flash.discard  # don't want the flash to appear when you reload page
  end

=begin
# js
$(document).ajaxError(function(event, request) {
  var flash = request.getResponseHeader('X-Flash');
  // Do something
});

=end