Rails 3 Cocoon link_to_add_association Renders Partial Twice - ruby-on-rails-3

Question

My partial gets rendered twice instead of only once, as expected. Any thoughts?
Here's my Person view
<%= simple_nested_form_for(#person) do |f| %>
<%= f.error_notification %>
<div class="form-inputs">
<%= f.input :name %>
<h3>Records by year</h3>
<div id='records'>
<%= f.simple_fields_for :records do |record| %>
<%= render 'record_fields', :f => record %>
<% end %>
<div class='links'>
<%= link_to_add_association 'New Record', f, :records, :class => 'btn' %>
</div>
</div>
</div>
<div class="form-actions">
<%= f.button :submit %>
</div>
<% end %>
Models (removed things such as constants and validations):
class Person < ActiveRecord::Base
attr_accessible :name, :records_attributes
has_many :records, :dependent => :destroy
accepts_nested_attributes_for :records, :reject_if => :all_blank, :allow_destroy => true
end
class Record < ActiveRecord::Base
attr_accessible :price, :status, :year, :person_id
belongs_to :person
end
My _record_fields.html.erb partial looks like this:
<div class='nested-fields well'>
<%= f.input :price %>
<%= f.input :year %>
<%= f.input :status, :collection => record_statuses, :include_blank => false %>
<%= link_to_remove_association "Remove", f %>
</div>
An interesting issue is that, if I change where the partials are generated (so 'after' instead of the default 'before' the link_to_add_association link), it generates a partial after the button, but the duplicate is generated before the link_to_add_association link.
The only similar issues reported on here I could find were with caching in production. This is happening in development, and my caching is turned off (by default).
Am I missing something? Can anyone help?
Edit:
Looking at the cocoon JavaScript, it seems the click event is called twice for one click (tested it with $('.add_fields').click(), which triggers $('.add_fields').live('click', function() {...} ) twice. I'm still at a loss as to why this might be happening. Input thoroughly appreciated.
Edit #2:
Controller:
# GET /persons/new
# GET /persons/new.json
def new
#person = Person.new
# #person.records.build
respond_to do |format|
format.html # new.html.erb
format.json { render json: #person }
end
end
# GET /persons/1/edit
def edit
#person = Person.find(params[:id])
end

Answer 1

I was having this same issue.
My problem was I requiring the cocoon javascript twice.
Once in my application.js
// app/assets/javascripts/application.js
//= require cocoon
and once in my application layout
/ app/views/layouts/application.html.haml
= javascript_include_tag :cocoon
after removing the include tag from my layout it began working as expected

Answer 2

Had the same issue, found that in my application layout (app/views/layouts/application.html.erb) I had already included application, and in application.js I had included cocoon. When including application.js in my view with cocoon, cocoon would fire twice.
(Same as above, but slightly different as I didn't explicitly specify cocoon in my application.html.erb, I specified application.js which included cocoon)

Answer 3

This happen when from application.js, you require two times cocoon, commonly, when you try change of jQuery to vanilla Javascript