title: Nested form has_many model. How to get id from nested item?
body: <p>I've got a nested form, structured: Question has_many Answers. So, the questions are multiple choice.</p>
  
  <p>Current form view:</p>
  
  <pre><code>- semantic_form_for @question do |f|
    = f.error_messages
    - f.inputs do
      = f.input :question
      = f.semantic_fields_for :answers do |builder|
        = builder.input :content, :label =&gt; "Answer", :input_html =&gt; { :class =&gt; {'required', ' ckeditor'}}
      = f.buttons
  </code></pre>
  
  <p>My question controller looks like:</p>
  
  <pre><code>  def new
      @question = Question.new
      4.times { @question.answers.build }
    end
  
    def create
      @question = Question.new(params[:question])
      @question.user_id = current_user.id
      if @question.save
        flash[:notice] = "Question added."
        redirect_to questions_url
      else
        render :action =&gt; 'new'
      end
    end
  </code></pre>
  
  <p>All pretty simple. However, now I would like to 'select' the correct answer, preferably on the same page, while adding. I think I will add a new column to Questions containing 'CorrectAnswerId' of some sort. But, how can I add it in the view &amp; controller?</p>