Rails show fields when radio button is checked

Question

I'm developing a Rails application and I need to show/hide a certain field when a radio button is clicked.

I'm using javascript but I can't seem to get it working.

Any tips on how to solve that?

Radio Button code

<%= radio_button 'relat', 'atu', 'yes' %>   ATU
<%= radio_button 'relat', 'atu', 'no' %>    No ATU

Field that's going to show when the first button is checked

<div id="esatu" style="display:none">
<p>
    <label for="relat_tipus_atu">
    Tipus ATU
    </label>
    <%= select_tag :tipus_id, "<option value=''></option>".html_safe + options_from_collection_for_select(@tipus, :id, :codi) %>
</p>

Answer 1

First, give your radio buttons some class names, so you can use them with javascript more easily.

<%= radio_button 'relat', 'atu', 'yes', {:class => "relat__atu relat__atu_yes"} %>   ATU
<%= radio_button 'relat', 'atu', 'no', {:class => "relat__atu relat__atu_no"} %>    No ATU

Now you attach an event handler to the change event. And toggle the display of your other element, depending if the radio button is the "yes" button.

$(".relat__atu").on("change", function(){
  $("#esatu").toggle($(this).hasClass("relat__atu_yes"));
});