PhoneGap Mobile Rails Authentication (devise? authentication from scratch?)

Question

I have a PhoneGap app with a Rails backend. I\'m trying to figure out what the best way is to authenticate a user from the mobile app using json.

I am using devise c

Answer 1

You should override devise's sessions and registrations controller. I'll only show you how to override the sessions controller:

First, go to your User model and add the Token Authenticatable module. Something like this:

devise :token_authenticatable

before_save :ensure_authentication_token

Then edit your devise.rb file to configure that module:

# You can skip storage for :http_auth and :token_auth by adding those symbols to the array below.
config.skip_session_storage = [:token_auth]

# Defines name of the authentication token params key
config.token_authentication_key = :auth_token

Now edit your routes and point to your new controllers:

devise_for :users, :controllers => { :registrations => 'registrations', :sessions => 'sessions' }

And then create your controller like this:

class SessionsController < Devise::SessionsController
  def create
    respond_to do |format|
      format.html {
        super
      }
      format.json {
        build_resource
        user = User.find_for_database_authentication(:email => params[:user][:email])
        return invalid_login_attempt unless resource

        if user.valid_password?(params[:user][:password])
          render :json => { :auth_token => user.authentication_token }, success: true, status: :created
        else
          invalid_login_attempt
        end
      }
    end
  end

  def destroy
    respond_to do |format|
      format.html {
        super
      }
      format.json {
        user = User.find_by_authentication_token(params[:auth_token])
        if user
          user.reset_authentication_token!
          render :json => { :message => 'Session deleted.' }, :success => true, :status => 204
        else
          render :json => { :message => 'Invalid token.' }, :status => 404
        end
      }
    end
  end

  protected
  def invalid_login_attempt
    warden.custom_failure!
    render json: { success: false, message: 'Error with your login or password' }, status: 401
  end
end

Devise has a page about this, but it only points to some already outdated guides. But maybe it will help you.