Rails 4 - Unpermitted Paramaters - Deeply nested attributes form not saving -

i'm working on nested attributes , running unpermitted attributes error.

log:

started post "/videos/1/quizzes" processing quizzescontroller#create html   parameters: {"utf8"=>"✓",  "authenticity_token"=>"xdj5lpz7quvezivybphnv0t/npmmtkval2dcwrxhvqu=",  "quiz"=>{"name"=>"test", "question"=>{"content"=>"test",  "answer"=>{"content"=>"test"}}}, "commit"=>"submit", "video_id"=>"1"}   video load (0.1ms)  select  "videos".* "videos"  "videos"."id" = ? limit 1  [["id", 1]]   unpermitted parameters: question 

so data being submitted. reading around looks nested question parameters supposed "question_attributes"=> in log shows "question"=>. don't know if has it? @ point it's idea.

quizzes#new:

def new   @video = video.find(params[:video_id])   @quiz = @video.build_quiz   @quiz.questions.build   @quiz.questions.each |question|      question.answers.build   end end 

the video_id params working , can see above being submitted.

quizzes#create

def create   @video = video.find(params[:video_id])   @quiz = @video.create_quiz(quiz_params)   respond_to |format|     if @quiz.save         format.html { redirect_to @quiz, notice: 'quiz created.' }         format.json { render :show, status: :created, location: @quiz }      else         format.html { render :new }         format.json { render json: @quiz.errors, status: :unprocessable_entity }     end   end end 

quizzes_params

def quiz_params    params.require(:quiz).permit(:name, questions_attributes: [:id, :content, :quiz_id, answers_attributes: [:id, :content, :question_id]]) end 

so can see it's stopping question parameters , answer parameters being saved.

let me know if need else! thank in advance help!

update here form partial! tried doing form_for @quiz |f| didn't change submitted. other thing tried pluarlizing :question , :answer :questions , :answers no luck.

  <%= form_for [@video, @quiz] |f| %>     <%= f.label :name, "title" %>     <%= f.text_field :name %>      <%= f.fields_for :question |questions| %>       <%= questions.label :content, "question" %><br>       <%= questions.text_area :content, rows: 3  %>        <%= questions.fields_for :answer |answers| %>         <%= answers.label :content, "answer" %>         <%= answers.text_field :content %>       <% end  %>      <% end %>     <%= f.submit "submit" %>    <% end %> 

solution:

i changed line in quizzes_controller @quiz.questions.build 2.times { @quiz.questions.build } , fixed issue. not sure why works now, does. explanation why appreciated!

def new     @video = video.find(params[:video_id])     @quiz = @video.build_quiz     2.times { @quiz.questions.build }     @quiz.questions.each |question|         question.answers.build     end end