Question

I’m just getting started using rails 3.1 and jQuery / coffee scripts. I have a piece of js code which works when included in a tag in my view but when included in app/assets/javascripts/post.js.coffee it throws the following error:

ExecJS::RuntimeError in Posts#new

Showing
/home/chris/RailsDev/blog/app/views/layouts/application.html.erb where
line #10 raised:

Reserved word “function” on line 7 (in
/home/chris/RailsDev/blog/app/assets/javascripts/post.js.coffee)

This works:

app/views/posts/new.html.erb

<%= form_for [@user, @post] do |f| %>
      <div class="field">
        <%= f.label :title %><br />
        <%= f.text_field :title %>
      </div>
      <div class="field">
        <%= f.label :content %><br />
        <%= f.text_area :content %>
      </div>
      <div class="field">
        <label for="forward_date">Post in the future?</label>
        <%= check_box_tag 'forward date' %>
        <div id="post_date" style="display: none;">
          <%= f.label :post_date %>
          <%= f.datetime_select :post_date %>
        </div>
      </div>
      <div class="actions">
        <%= f.submit "Create" %>
      </div>
    <% end %>
    <script>
      $("#forward_date").change(function() {
        if($(this).is(":checked")) {
          $("#post_date").show("slow");
        } else {
          $("#post_date").hide("slow");
        }
      });
    </script>

This throws ExecJS::RuntimeError

Remove the tag from the view and place the code in app/assets/javascripts/post.js.coffee

$("#forward_date").change(function() {
  if($(this).is(":checked")) {
    $("#post_date").show("slow");
  } else {
    $("#post_date").hide("slow");
  } 
});

Answer 1

the coffeescript isn’t coffeescript

should be:

$("#forward_date").change ->
  if $(this).is(":checked")
    $("#post_date").show "slow"
  else
    $("#post_date").hide "slow"