How to make preloader on send_data?

Question

Ruby on Rails

There is an action that, upon request, pumps out a large amount of data. How to let the user know that his request is being fulfilled? AJAX is not an option - send_data doesn't work. In Resque.enqueue send_data doesn't work either. What to do?
Thanks everyone for the replies.

Answer 1

You can add to the button:
And also by pressing it with the help of JavaScript, you can turn all the fields into "read-only", and also with the help of the same JavaScript you can display an animated icon (see fa-spin at Font Awesome) and an inscription next to it, they say : "Please wait. Your request is being processed."
Or is it better to do so. Add this to the form:
Next, look at the ID of the form and add a JS handler (CoffeeScript):

$(document).ready ->
  $("#form-id").on("ajax:success", (e, data, status, xhr) ->
    #	Тут какой-нибудь код, когда все хорошо. Передаваемый JSON доступен в data.
  ).on "ajax:error", (e, xhr, status, error) ->
    #	Тут какой-нибудь код, когда все очень плохо.
return

As a result, if success or error, then hide the form and progress, and then one or another message is displayed in place of all this.