title: Using devise with nested form on sign_up
body: <p>The form doesn't show the Pessoa's field, what's wrong?</p>
  
  <pre><code>&lt;%= form_for(resource, as: resource_name, url: registration_path(resource_name)) do |f| %&gt;
    &lt;%= devise_error_messages! %&gt;
  
    &lt;h4&gt;Usuário&lt;/h4&gt;
  
      &lt;%= f.email_field :email, autofocus: true %&gt;
  
      &lt;% if @minimum_password_length %&gt;
        &lt;em&gt;(&lt;%= @minimum_password_length %&gt; characters minimum)&lt;/em&gt;
      &lt;% end %&gt;&lt;br /&gt;
      &lt;%= f.password_field :password, autocomplete: "off" %&gt;
  
      &lt;%= f.password_field :password_confirmation, autocomplete: "off" %&gt;
  
    &lt;h4&gt;Pessoa&lt;/h4&gt;
  
    &lt;%= f.fields_for :pessoa do |p| %&gt;
        &lt;%= p.text_field :nome %&gt;   
    &lt;% end %&gt;
  
    &lt;div class="actions"&gt;
      &lt;%= f.submit "Cadastrar" %&gt;
    &lt;/div&gt;
  
  &lt;% end %&gt;
  </code></pre>
  
  <p>I just see, email, password and password confirmation...
  class User:</p>
  
  <pre><code>class Usuario &lt; ActiveRecord::Base
  
    has_one :pessoa
    has_many :pedidos, through: :pessoa
  
    accepts_nested_attributes_for :pessoa
  </code></pre>
  
  <p>And RegistrationController:</p>
  
  <pre><code>class Usuarios::RegistrationsController &lt; Devise::RegistrationsController
  
    def new
      build_resource(sign_up_params)
      self.resource.pessoa = Pessoa.new
      respond_with self.resource
    end
  
    def create
      super
    end
  
    private
  
    def sign_up_params
      params.require(:user).permit(pessoas_attributes: [:nome])
    end
  
  end
  </code></pre>
  
  <p>Pessoa belongs to Usuario, ok? And need show email, password, password confirmation and name. When submit need save in two tables (Usuarios and Pessoas) the values registered. What I'm wrong? Thanks!</p>
  
  <p>EDIT</p>
  
  <p>The form Pessoa show, but after I filled out the data, dont save in DB, why? I did what I was asked to do. The user values save ok, but pessoas dont.</p>