Cocoon add association, how to limit number of associations

Question

I am creating a system that stores cards using Ruby/Rails/HAML - In this case there is a Card class that has many Colours (this is also a class). When creating and editing a

Answer 1

I had a similar task to do and what I ended up doing was putting an onclick event on the "Add" link. This onclick event will execute before the code to add the fields is executed.

In your case, the code would look something like the following:

= link_to_add_association 'add colour', c, :colours, class: 'add-colour-link'

Then in your JavaScript (CoffeeScript in this case):

$('.add-colour-link').on 'click', (e) ->
   if $('#colours .nested-fields:visible').size() < 5
     return true #continue the execution 
   else
     #maybe display the modal to the user that only a maximum of 5 is allowed
     return false #prevent further execution

Answer 2

I would use javascript for this. You can bind to an event that is triggered upon insert of a new item: on this event count how many items there are, and hide the link if needed.

Likewise, when loading the page do the same.

So in code that would look like:

 $(function() {
   function check_to_hide_or_show_add_link() {
     if ($('#colours .nested-fields:visible').length == 5) {
       $('#colours .links a').hide();
     } else {
       $('#colours .links a').show();
     }
   }

   $('#colours').on('cocoon:after-insert', function() {
     check_to_hide_or_show_add_link();
   });

   $('#colours').on('cocoon:after-remove', function() {
     check_to_hide_or_show_add_link();
   });

   check_to_hide_or_show_add_link();     
 });

Something like this should work. Note this code is not tested :)

Hope this helps.