Resolve issue where Safari 7 and iOS 7 Mobile Safari incorrectly render cached pages when a 304 response is returned from the server.

application_controller.rb

class ApplicationController < ActionController::Base
 
  before_filter :delete_if_none_match_header

private

  # Encountered bug where Safari 7 would fail to render pages when ETAG-based caching kicks in
  # This should prevent Safari from attempting such caching
    def delete_if_none_match_header
    if request.format.html? && request.headers['If-None-Match'] != nil && is_safari?()
      request.headers['If-None-Match'] = nil
    end
  end

  def is_safari?
    ua = request.env['HTTP_USER_AGENT']
    return (ua.match('Intel Mac OS X') || ua.match('iPhone OS')) && ua.match('Safari')
  end

end

For more info: IOS7-BUG: SHOWS WHITE PAGE WHEN GETTING 304 NOT MODIFIED FROM SERVER