Multi nested form in ruby on rails - ruby-on-rails-4

Question

I have a scenario where my application interacts with three models called User, Question and Answer. I added three questions for a user from admin panel or through rails console. Now in separate action i need to display all the questions of a particular user and providing a option of adding multiple answers as text for each. I don't know how to proceed further. Here is my sample code which i tried.
class User
has_many :questions
accepts_nested_attributes_for :questions
end
class Question
belongs_to :user
has_many :answers
accepts_nested_attributes_for :answers
end
class Answer
belongs_to :question
end
users_controller.rb
class UserController
def display_questions
#user = current_user
end
end
views/display_questions.html.erb
<%= form_for #user do |f| %>
<%= f.fields_for :questions do |q| %>
<%= q.fields_for :answers do |a| %>
<%= a.text_field :name %>
<% end %>
<%= q.link_to_add 'Add', :answers %>
<% end %>
<% end %>
I am getting all the questions for that user but not able to add answers for individual question. I am confused how to build nested fields for these scenario, any help is appreciated. Thanks

Answer 1

If you use the nested_form gem it's pretty easy, just do:
<%= nested_form_for #user do |f| %>
<%= f.fields_for :questions do |q| %>
<%= q.fields_for :answers do |a| %>
<%= a.text_field :name %>
<% end %>
<%= q.link_to_add 'Add', :answers %>
<% end %>
<% end %>
Note the nested_form_for instead of form_for
Also, you will need to add the property accepts_nested_attributes_for for the models which correspond:
class User < ActiveRecord::Base
has_many :questions
accepts_nested_attributes_for :questions
end
class Question < ActiveRecord::Base
belongs_to :user
has_many :answers
accepts_nested_attributes_for :answers
end
class Answer < ActiveRecord::Base
belongs_to :question
end