Rails 4 & Coffee Script form helper to hide on unchecked field - ruby-on-rails

Question

I am trying to make an app in Rails 4.
I use simple form for the form and have a js form helper file which I use to have javascript hide or show form elements depending on how users answer questions as they move through the form.
My problem is that this js function works fine on the initial create, but if i come back to edit the form, the reminder id content is shown when the draft attribute is == false.
Is there another way to approach this problem?
My form has:
<%= f.simple_fields_for :scope do |finalises_s| %>
<%= finalises_s.simple_fields_for :finalise do |dr| %>
<div class="row">
<div class="col-md-3 col-md-offset-1">
<%= dr.label :draft, 'Would you like to save this draft and finish it later?', class: 'question-project' %>
</div>
<div class="col-md-7">
<%= dr.collection_radio_buttons :draft, [[true, ' Yes, save a draft'], [false, ' No, publish it']], :first, :last, {:item_wrapper_class => 'fixradio'}, {:class => "response-project"} %>
</div>
</div>
<div id="reminder">
<div class="row">
<div class="col-md-3 col-md-offset-1">
<%= dr.label :reminder, 'Would you like a reminder to complete this draft?', class: 'question-project' %>
</div>
<div class="col-md-7">
<%= dr.collection_radio_buttons :reminder, [[true, ' Yes'], [false, ' No']], :first, :last, {:item_wrapper_class => 'fixradio'}, {:class => "response-project"} %>
</div>
</div>
My js form-helper file has:
if $("input:radio[name='"+ inString + "[scope_attributes][finalise_attributes][draft]']").is(':checked')
$('#reminder').show()
else
$('#reminder').hide()
$(document).on 'change', "input:radio[name='"+ inString + "[scope_attributes][finalise_attributes][draft]']", ()->
if $(this).val() == 'true'
$('#reminder').show()
else
$('#reminder').hide()

Answer 1

There are probably a few different ways to do this, but I did something very similar.
Attach an id or class to the radio button you can use to bind later (in my case, for each radio/value combination, I added a unique class like class: this_radio_value_true).
Similarly, attach an id or class to the sections of markup you want to impact (in my case, I added an id to a form_group which I wanted to hide/show like id: stuff_to_control).
Trigger jQuery for these elements:
$('.this_radio_value_true').on('click', function() {
$('#stuff_to_control').show();
});
$('.this_radio_value_false').on('click', function() {
$('#stuff_to_control').hide();
});

Answer 2

It's probably because TurboLinks. You can't use $(document).on 'change'. You have to listing for TurboLink events. Rails doesn't load the entire page each time. It only loads the content inside the layout. You have to use
$(document).on 'ready page:load', ->
Here's the docs: https://github.com/rails/turbolinks/#events
Guide: http://guides.rubyonrails.org/working_with_javascript_in_rails.html#page-change-events