"param is missing or the value is empty" in nested form

Question

I'm currently trying to build a really simple nested form app in my quest to learn rails. In this app I have three models legal_form answer and question. I have my my answers.html.erb, set up as follows:

<%= form_for (@legal_form) do |f| %>
<h1>Title <%= @legal_form.title %></h1>
<p><%= @legal_form.description %></p>
<ul>
  <% @legal_form.questions.each do |question| %>
    <%= fields_for question.answers.build do |q| %>
      <li>
        <%= question.question_content %>
        <%= q.text_field :answer_content %>
      </li>
    <% end =%>
  <% end %>
</ul>

<p><%= f.submit "Submit" %></p>
<% end %>

Which currently grabs the three questions I have stored and renders text input boxes next to them; works without a problem. However, when I submit the values, I get the "param is missing or empty: legal_form".

I figure that this is most likely due to my strong params configuration in the legal_forms controller, see below.

class LegalFormsController < ApplicationController
  before_action :find_legal_form, only: [:show, :edit, :update, :destroy, :answers]

  def index
    @legal_form = LegalForm.all.order("created_at DESC")
  end

  def show
  end

  def new
    @legal_form=LegalForm.new
  end

  def create
    @legal_form = LegalForm.new(legal_form_params)

    if @legal_form.save
      redirect_to @legal_form, notice: "Successfully created new legal form."
    else
      render 'new'
    end
  end

  def edit
  end

  def update
    if @legal_form.update(legal_form_params)
      redirect_to @legal_form
    else
      render 'edit'
    end
  end

  def destroy
    @legal_form.destroy
    redirect_to root_path, notice: "Successfully deleted form"
  end

  def answers
    @questions=@legal_form.questions
    @legal_form=LegalForm.find(params[:id])
  end
  private

  def legal_form_params
    params.reqire(:legal_form).permit(:title, :description, :questions_attribute => [:id, :question_number, :question_content, :_destroy, :answer_attributes => [:id, :answer_content, :question_id, :user_id]])
  end

  def find_legal_form
    @legal_form=LegalForm.find(params[:id])
  end
end

And, in case it's helpful, here are the models for each.

class Answer < ActiveRecord::Base
  belongs_to :question
end

class LegalForm < ActiveRecord::Base
  has_many :questions, :dependent => :destroy

  has_many :answers, through: :entity_roles

  accepts_nested_attributes_for :questions,
  reject_if: proc { |attributes| attributes['question_content'].blank? },
  allow_destroy: true

end

class Question < ActiveRecord::Base
  belongs_to :legal_form
  has_many :answers
  accepts_nested_attributes_for :answers,
  reject_if: proc { |attributes| attributes['question_content'].blank? },
  allow_destroy: true
end

Also, as requested here's my routes file:

Rails.application.routes.draw do
  resources :legal_forms do
    member do
      get 'answers'
    end
  end

  resources :answers

  root "legal_forms#index"
end

Any help to finally conquer nested forms would be greatly appreciated. I've been banging my head against it off and on for about a week now. Many thanks in advance.

Answer 1

Try in the controller

def legal_form_params
  params.require(:legal_form).permit(...)
end

Also question.answers.build add it to the method of your controller and call the object that returns the responses to fields_for

UPDATE

To be sent through this form your results, should probably be like this

form

<%= f.fields_for :answers do |q| %>
      ...
<% end =%>

in the new method

 def new
    @legal_form=LegalForm.new
    @answers = @legal_form.question.answers.build
 end

def legal_form_params
   params.require(:legal_form).permit! #temporarily
end

not tried it, but imagine how it works something like this