Question

Is there any helper method available which shows/hides specified div based on the value of a model attribute?

Here is the partial where I want to show div that wraps openid_domain_name text field if openid_enabled is true and hide otherwise while editing record.

<%= form_for @application do |f| %>
    <%= render "shared/error_messages", target: @application %>
    <p>
      <%= f.label :name %>
      <%= f.text_field :name %>
    </p>
    <p>
      <%= f.label :description %>
      <%= f.text_field :description %>
    </p>   
    <p>
      <%= f.check_box :openid_enabled %>
      <%= f.label 'openid', 'OpenID' %>
      <div id="application_openid_domain" style="display: none;">
        <%= f.label :openid_domain_name %>
        <%= f.text_field :openid_domain_name %>
      </div>
    </p>
    <p><%= f.submit class: "btn btn-primary" %></p>
<% end %>

Here is the javascript that shows/hides the div when user checks/unchecks the check box.

<script type="text/javascript">
     $(function() {
        $(':checkbox').click(function () {
          if ($(this).is(':checked'))
            $("#application_openid_domain").show();
          else
            $("#application_openid_domain").hide();            
        });
    });
</script>

EDITED
Generated HTML Source:

<form accept-charset="UTF-8" action="/applications" class="new_application" id="new_application" method="post"><div style="margin:0;padding:0;display:inline"><input name="utf8" type="hidden" value="&#x2713;" /><input name="authenticity_token" type="hidden" value="Cq2rYF1qkjnsobimMTAUvle9Hi82LwdvghcVWRtC/I0=" /></div>
  <p>
    <label for="application_name">Name</label>
    <input id="application_name" name="application[name]" size="30" type="text" />
  </p>
  <p>
    <label for="application_description">Description</label>
    <input id="application_description" name="application[description]" size="30" type="text" />
  </p>
  <p>
    <input name="application[openid_enabled]" type="hidden" value="0" /><input id="application_openid_enabled" name="application[openid_enabled]" type="checkbox" value="1" />
    <label for="application_openid">OpenID</label>
    <div id="application_openid_domain" style="display: none;">
      <label for="application_openid_domain_name">Openid domain name</label>
      <input id="application_openid_domain_name" name="application[openid_domain_name]" size="30" type="text" />
    </div>
  </p>
  <p><input class="btn btn-primary" name="commit" type="submit" value="Create Application" /></p>
</form>

<script type="text/javascript">
     $(function() {
        $(':checkbox').click(function () {
          if ($(this).is(':checked'))
            $("#application_openid_domain").show();
          else
            $("#application_openid_domain").hide();            
        });
    });
</script>

Answer 1

I have written custom helper to do the same. Please suggest if it is correct solution or not.

app/helper/application_helper.rb

def show_hide(show)
  show ? 'block' : 'none'
end

app/views/applications/_form.html.erb

<div id="application_openid_domain" style="display: <%= show_hide(@application.openid_enabled?)%>;">
  <%= f.label :openid_domain_name %>
  <%= f.text_field :openid_domain_name %>
</div>