complex form how to deal

gistfile1.rb

#in model user.rb
class User < ActiveRecord::Base
  has_one :addresses
end
#in model address.rb
class Address < ActiveRecod::Base
  blongs_to :user
end

#in controller users_controller.rb
class UserController < ApplicationController
  respond_to :html
  
  def index
  end
  
  def new
    @user = user.new
  end
  
  def create
    @user = User.build(@attributes)
    @user.save
    respond_with @user, location: new_user_path, action: :new
  end
  
  private
  def build_attributes
    @attributes = params.require(:user).permit(:name 
    address {
      :location 
    }
    )
end

#in page new.html.erb
<%= form_for(setup_user(@user), url: users_path) do |f|%>
  <%= f.label :name %>
  <%= f.text_field :name%>
  <%= f.fields_for  :address do |ff|%>
    <%= f.label :location %>
    <%= f.text_field %>
  <% end %>
  <%= f.submit %>
<% end %>

#in helper user_helper.rb
module UserHelper
  def setup_user(user)
    user.address ||= Address.new
    user
  end
end