UsersController＃create中的ArgumentError； 参数数量错误（2代表0）

Question

I'm getting the error "wrong number of arguments (2 for 0) from 'build_profile' function in user.rb while trying to add a profile to a user using the one to one relationship.

Models

User.rb

class User < ActiveRecored::Base
  has_one :profile, dependent: :destroy
  after_create :build_profile

  accepts_nested_attributes_for :profile
  attr_accessible :email, :password, :password_confirmation, :profile_attributes

  def build_profile
    Profile.create(user: self)
  end
end

Profile.rb

class Profile < ActiveRecord::Base
   attr_accessible :name. :address, :age
   belongs_to :user

   validates :name, presence: true, length: { maximum: 50 }
   validates :address, :age,  presence: true
end

Users_controller.rb

class UsersController < ApplicationController
    def new
       @user = User.new
       @profile = self.build_profile 
    end

    def create
       @user = User.new(params[:user])
       if @user.save 
         sign_in @user
         flash[:success] = "welcome, Thanks for Signing up"
         redirect_to @user
       else
         render 'new'
       end
    end

end

Profiles_controller.rb

class ProfilesController < ApplicationController

  def edit 
     @profile = Profile.find(params[:id])
  end

  def show 
   @user.profile = User.find(params[:id]).profile
  end

  def destroy
  end

end

I get this error when a user tries to sign up , below is the sign up form

Sign Up Form

<h1> Sign Up </h1>
  <div class="span6 offset3">
  <%= form_for (setup_user(@user)) do |f| %>
     <%= f.fields_for :profile do |ff| %>
     <p>
        <%= ff.label :name %>
        <%= ff.text_field :name %>
     </p>
     <% end %>
     <p>
          <%= f.label :email %>
          <%= f.text_field :email %>
     </p>
     <p>
          <%= f.label :password %>
          <%= f.pasword_field :password %>
     </p>
     <p>
          <%= f.label :password_conformation, "Confirm Password" %>
          <%= f.password_field :password_confirmation%>
     </p>
    <%= f.submit "create my account", class: "btn btn-large btn-primary" %>
 <% end %>

Thanks

Server Log Output for posting the user new form

Started POST "/users" for 127.0.0.1 at 2014-10-13 10:01:42 -0400
Processing by UsersController#create as HTML
Parameters: {"utf8"=>"G£ô", "authenticity_token"=>"7PQwoH4VGDE2kyHqjkv4PegFz/A
KYGYXRFtQpn9UKko=", "user"=>{"profile_attributes"=>{"name"=>"Example Test"}, "em
ail"=>"example@test.com", "password"=>"[FILTERED]", "password_confirmation"=>"[F
ILTERED]"}, "commit"=>"Create my account"}
(0.0ms)  BEGIN
User Exists (25.0ms)  SELECT 1 AS one FROM `users` WHERE `users`.`email` = 'ex
ample@test.com' LIMIT 1
(0.0ms)  ROLLBACK
Rendered users/new.html.erb within layouts/application (4.0ms)
User Load (1.0ms)  SELECT `users`.* FROM `users` WHERE `users`.`remember_token
` IS NULL LIMIT 1
Rendered layouts/_header.html.erb (3.0ms)
Rendered layouts/_footer.html.erb (0.0ms)
Completed 200 OK in 330ms (Views: 93.0ms | ActiveRecord: 26.0ms)

Answer 1

It's because build_profile is a method already defined by Rails.

Try changing the name:

after_create :build_default_profile

def build_default_profile
  Profile.create(user: self)
end

Answer 2

Since you are already defining a relationship for these two models (user has_one :profile), the build_profile is already defined for you. No need to do so in your model. take a look at http://edgeguides.rubyonrails.org/association_basics.html for more details.

Answer 3

I have been able to finally found a solution to both queries i had; the latter resulting from attempted solution from my first question.

A. ArgumentError in UsersController#create; Wrong number of arguments (2 for 0)

B. Form_for taking in values and not posting to database.

I am posting my solution here for future references for any one run into either problems with their codes.

Andrew, Thanks for referring me to the guide, it was an educational read. Juanpastas, Thanks. You helped solved both queries, though i ended up using Profile.create(user_id: self.id) instead of Profile.create(user: self) due to trouble with mass assignment of protected values. Your comment requesting the server log output made me scrutinize the log and noticed that it was rolling back the parameters instead of saving them to the database. Through research and other post on here such as, how to find the cause of ActiveRecord ROLLBACK (Serge Seletskyy's answer), and Max Wong's answer in Why does my rails rollback when I try to user.save? , I learned it might be due to failing validations Using User.save! as the if condition in my User's create function helped see that some other attributes and the line validates :address, :age, :sex, presence: true in the profile model was making the callback function to fail validation as they can't be blank and return false, causing the rollback by the server, but commenting out the line, #validates :address, :age, :sex, presence: true , solved it.