Devise and simple-private-messages

I am using Devise in my Ruby on Rails 3 application. I am trying to implement private messaging in my application and I came across this gem:

https://github.com/jongilbraith/simple-private-messages

I (accidentally) ran the following command.

rails generate simple_private_messages:model User Message

It created the Message model. But it changed some properties of my existing 开发者_开发百科User model that I had generated using Devise using the following command:

    rails generate devise User

Now, when I start my Ruby on Rails application I get this warning:

[WARNING] You provided devise_for :users but there is no model User defined in your application

And my Devise links have stopped working:

ActionView::Template::Error (undefined local variable or method `edit_user_registration_path' for #<#:0x1064c9490>):

Can someone please suggest how can I integrate the both or revert my changes if it is not possible to use them simultaneously?

I've followed these steps to install the gem:

rails generate devise:install

rails generate devise User

rails generate simple_private_messages:model User Message

Add this line (has_private_messages) to User Model:

class User < ActiveRecord::Base
    # Include default devise modules. Others available are:
    # :token_authenticatable, :encryptable, :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

    has_private_messages

end

Edit the routes.rb file, the order is important here, devise_for should be defined before the messages routes.

devise_for :users

resources :users do
    resources :messages do
        collection do
            post :delete_selected
        end
    end
end

If you want the scaffold:

rails generate simple_private_messages:scaffold User Message

And remember to uncomment this (attr_accessor :to):

class Message < ActiveRecord::Base

  is_private_message

  # The :to accessor is used by the scaffolding,
  # uncomment it if using it or you can remove it if not
  attr_accessor :to
end