undefined method `values_at' using nested_form gem

forms, nested-forms, ruby-on-rails, ruby-on-rails-3

Solution

As mentioned in the documentation for the nested_form gem, you have to mention the field_for of the nested object before link_to_load button. I haven't use this gem previously but after going through the documentation, i am guessing this.

Here the form looks like

<%= nested_form_for [:admin, @poll], mutipart: true, class: "form-horizontal" do |f| %>
  <%= f.text_field :question %>
  <%= f.fields_for :poll_answers do |poll_ans_form| %>
    <%= poll_ans_form.text_field :name %>
    <%= poll_ans_form.link_to_remove "Remove this task" %>
  <% end %>
  <p><%= f.link_to_add "Add a Answer", :poll_answers %></p>
<% end %>

Problem

I am getting the error ``` ActionView::Template::Error (undefined method `values_at' for nil:NilClass): ``` when using nested_form gem Here is my code Models ``` class Poll < ActiveRecord::Base attr_accessible :question, :poll_answers_attributes has_many :poll_answers accepts_nested_attributes_for :poll_answers end class PollAnswer < ActiveRecord::Base belongs_to :poll attr_accessible :answer end ``` View ``` =nested_form_for [:admin, @poll], mutipart: true, class: "form-horizontal" do |f| .span6 .control-group =f.label :question, class: "control-label" .controls =f.text_field :question, rows: "5", class: "span5" = f.link_to_add "Add a Answer", :poll_answers =f.submit "Create Post", class: "btn btn-primary" ``` StackTrace ``` /home/abid/.bundler/ruby/1.9.1/nested_form-6232dd853c27/lib/nested_form/builder_mixin.rb:41:in `block in link_to_add' /home/abid/.bundler/ruby/1.9.1/nested_form-6232dd853c27/lib/nested_form/view_helper.rb:53:in `call' /home/abid/.bundler/ruby/1.9.1/nested_form-6232dd853c27/lib/nested_form/view_helper.rb:53:in `after_nested_form_callbacks' /home/abid/.bundler/ruby/1.9.1/nested_form-6232dd853c27/lib/nested_form/view_helper.rb:8:in `block in nested_form_for' ``` Any Ideas ?

Original source