undefined method in the form

[sutherland007]

Using the Contests controller example, I'm going to add a simple correction for the controller, because it throws an undefined method 'base_class'. I've solved it by adding this:

class ContestsController < ApplicationController

  helper_method :survey, :participant

  # create a new attempt to this survey
  def new
    @participant = current_user #notice this and the base_class error disappears
    @attempt = survey.attempts.new
    # build a number of possible answers equal to the number of options
    survey.questions.size.times { @attempt.answers.build }
  end

  # create a new attempt in this survey
  # an attempt needs to have a participant assigned
  def create
    @attempt = survey.attempts.new(params[:attempt])
    # ensure that current user is assigned with this attempt
    @attempt.participant = participant
    if @attempt.valid? and @attempt.save
      redirect_to contests_path
    else
      render :action => :new
    end
  end

  def participant
    @participant ||= current_user
  end

  def survey
    @survey ||= Survey::Survey.active.first
  end
end

But as I said before the 'base_class' error disappears and throws another error in the form.

<%= form_for [:contests, @attempt] do |f| %>  <!-- the error is this line it says 'undefined method for contest_survey_attemps_path' -->
  <%= f.fields_for :answers do |builder| %>
    <ul>
      <% @survey.questions.each do |question| %>
        <li>
          <p><%= question.text %></p>
          <%= builder.hidden_field :question_id, :value => question.id %>
          <% question.options.each do |option| %>
            <%= builder.check_box :option_id, {}, option.id, nil %>
            <%= option.text %> <br/ >
          <% end -%>
        </li>
      <% end -%>
    </ul>
  <% end -%>
  <%= f.submit "Submit" %>
<% end -%>

I'm using Rails 4