#196 Nested Model Form (revised)

class Survey < ActiveRecord::Base
  attr_accessible :name, :questions_attributes
  has_many :questions
  accepts_nested_attributes_for :questions, allow_destroy: true
end

class Question < ActiveRecord::Base
  attr_accessible :content, :survey_id, :answers_attributes
  belongs_to :survey
  has_many :answers
  accepts_nested_attributes_for :answers, allow_destroy: true
end

<%= f.fields_for :questions do |builder| %>
  <%= render 'question_fields', f: builder %>
<% end %>
<%= link_to_add_fields "Add Question", f, :questions %>

<fieldset>
  <%= f.label :content, "Question" %><br />
  <%= f.text_area :content %><br />
  <%= f.check_box :_destroy %>
  <%= f.label :_destroy, "Remove Question" %>
  <%= f.fields_for :answers do |builder| %>
    <%= render 'answer_fields', f: builder %>
  <% end %>
  <%= link_to_add_fields "Add Answer", f, :answers %>
</fieldset>

<fieldset>
  <%= f.label :content, "Answer" %>
  <%= f.text_field :content %>
  <%= f.hidden_field :_destroy %>
  <%= link_to "remove", '#', class: "remove_fields" %>
</fieldset>

jQuery ->
  $('form').on 'click', '.remove_fields', (event) ->
    $(this).prev('input[type=hidden]').val('1')
    $(this).closest('fieldset').hide()
    event.preventDefault()

  $('form').on 'click', '.add_fields', (event) ->
    time = new Date().getTime()
    regexp = new RegExp($(this).data('id'), 'g')
    $(this).before($(this).data('fields').replace(regexp, time))
    event.preventDefault()

module ApplicationHelper
  def link_to_add_fields(name, f, association)
    new_object = f.object.send(association).klass.new
    id = new_object.object_id
    fields = f.fields_for(association, new_object, child_index: id) do |builder|
      render(association.to_s.singularize + "_fields", f: builder)
    end
    link_to(name, '#', class: "add_fields", data: {id: id, fields: fields.gsub("\n", "")})
  end
end