Help on getting multiple answers on a polls app

Hello community,

I’m working on a polls app and the the user would answer to 3 types of questions:

Open answers;

Multiple Choice with only one option to select (radio buttons);

Multiple Choice with many options to select (checkboxes).

i’ve already done the first and the second type of question, but i’m struggling with the checkboxes.

This are my models:

answer.rb

class Answer < ActiveRecord::Base
  belongs_to :reply
  belongs_to :question
  belongs_to :possible_answer
end

poll.rb

class Poll < ActiveRecord::Base
validates_presence_of :title

has_many :questions
has_many :replies
end

**possible_answer.rb**

class PossibleAnswer < ActiveRecord::Base
belongs_to :question
end

question.rb

class Question < ActiveRecord::Base
  belongs_to :poll

  has_many :possible_answers
  has_many :answers

  accepts_nested_attributes_for :possible_answers, reject_if: proc { |attributes| attributes['title'].blank? }
end

reply.rb

class Reply < ActiveRecord::Base
belongs_to :poll
has_many :answers

accepts_nested_attributes_for :answers
end

In the views I have a reply/new.html.erb that already work for radio and open answer questions, by rendering the partial by kind:

<h1><%= @poll.title %></h1>

<%= form_for [ @poll, @reply ] do |f| %>
    <%= f.fields_for :answers do |c| %>
        <%= render c.object.question.kind, c: c %>
    <% end %>
    <p>
      <%=f.submit 'Finish poll', class: 'btn btn-primary'%>
    </p>
<% end %>

and the partial for the checkbox:


<%= c.label :value, c.object.question.title %>

<% c.object.question.possible_answers.each do |possible_answer| %>

<%= check_box_tag( 'possible_answer_id['+ possible_answer.id.to_s+']', possible_answer.id) %> <%= possible_answer.title %> <%= c.hidden_field :question_id %>

<% end %>
``` ```
and the partial for the radio buttons:

<p>

<%= c.label :value, c.object.question.title %>

<% c.object.question.possible_answers.each do |possible_answer| %>

<%= c.radio_button :possible_answer_id, possible_answer.id %> <%= possible_answer.title %> <%= c.hidden_field :question_id %>

<% end %>
``` ```

This is my data base model:

[<img src="https://lh3.googleusercontent.com/-p-nacDnZds8/VmXPoMH4c1I/AAAAAAAAPB8/LpKFndQGNeE/s400/1-Home.png" border="0" style="" width="400" height="318">](https://lh3.googleusercontent.com/-p-nacDnZds8/VmXPoMH4c1I/AAAAAAAAPB8/LpKFndQGNeE/s1600/1-Home.png)

for now i can reply to a poll and answer to the 3 kind of questions but the checkboxes kind won’t save to the answers table

Probably I have to use has_many through association in the answers model but I’m not getting how. Can someone help me?

Thanks!