capybara wait for ajax calls to complete

def wait_for_ajax(timeout=5, increment=0.5) #Timeout in seconds

    # this is not exactly precise in terms of time elapsed but good enough

    timespan = 0

    loop do

      break if page.execute_script "return jQuery.active == 0"

      sleep increment

      timespan += increment

      if timespan > timeout

        flunk "Wait for AJAX timed out after waiting for #{timeout} seconds"

      end

    end

  end