Rails: Trouble adding belongs_to relationship to Devise User Registration form - ruby-on-rails

Question

So, I'm trying to add a selection for a belongs_to relationship in the User Registration form.
For example:
Here's the User model:
class User < ActiveRecord::Base
# Include default devise modules. Others available are:
# :token_authenticatable, :confirmable,
# :lockable, :timeoutable and :omniauthable
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable
# Setup accessible (or protected) attributes for your model
attr_accessible :email, :password, :password_confirmation, :remember_me
# attr_accessible :title, :body
belongs_to :thing
validates_presence_of :thing
end
Thing model:
class Thing < ActiveRecord::Base
attr_accessible :name
has_many :user
validates_presence_of :name
validates :name, :uniqueness => { :case_sensitive => false }
end
So, I've added some code to the app/views/devise/registration/new.html.haml file:
%h2 Sign up
= form_for(resource, :as => resource_name, :url => registration_path(resource_name)) do |f|
= devise_error_messages!
%div
= f.label :email
%br
= f.email_field :email, :autofocus => true
%div
= f.label :password
%br
= f.password_field :password
%div
= f.label :password_confirmation
%br
= f.password_field :password_confirmation
%div
= f.label :thing
%br
= f.select :thing, #things.map{ |r| [r.name, r.id] }
%div
= f.submit "Sign up"
= render "devise/shared/links"
So this all works fine, I can select the things from the select box. However, handling the submit is what I'm getting confused about. With this how it is, I'm getting a "can't mass assign protected attributes" error, which is what it should be doing.
How can I override the Devise controller to handle this? I've tried something like:
class RegistrationsController < Devise::RegistrationsController
def new
#things = Thing.all.sort_by{|e| e[:name]}
super
end
def create
#user = User.new(params[:user][:email], params[:user][:password])
#user.thing = params[:user][:thing]
super
end
end
but I get the feeling this is not anywhere close to what I'm supposed to do. Any help would be appreciated! Thanks!

Answer 1

Adding a relationship between two models can't be done without database changes. Rails don't change the database automatically to you, you need to write a migration for that. You can check on rails guides how to add a rails has_many relationship, and overall, I recommend take a good read in the model/view/controller sections form index before start using rails. It should take you no more than two days to read this stuff and if you understand what you are doing you will be able to do things better/faster.

Answer 2

So I figured it out.
I had to add a create method in the Registrations controller to override the Devise one.
class RegistrationsController < Devise::RegistrationsController
def new
#things = Thing.all.sort_by{|e| e[:name]}
super
end
def create
#things = Thing.all.sort_by{|e| e[:name]}
#user = User.new(email: params[:user][:email], password: params[:user][:password], password_confirmation: params[:user][:password_confirmation])
#user.thing = Thing.find(params[:user][:thing])
if #user.save
if #user.active_for_authentication?
set_flash_message :notice, :signed_up if is_navigational_format?
sign_up(:user, #user)
respond_with #user, :location => after_sign_up_path_for(#user)
else
set_flash_message :notice, :"signed_up_but_#{#user.inactive_message}" if is_navigational_format?
expire_session_data_after_sign_in!
respond_with #user, :location => after_inactive_sign_up_path_for(#user)
end
else
clean_up_passwords #user
respond_with #user
end
end
end
I basically copy and pasted the one from the Devise source code and put the save code for my object in there.