API Authentication using Devise (Ruby on Rails)

Question

I'm trying to add Authentication via json in my project using devise configuration :token_authenticatable.

I have the working sessions_controller#create code which was taken from this article - http://blog.codebykat.com/2012/07/23/remote-api-authentication-with-rails-3-using-activeresource-and-devise/

def create
    build_resource
    resource = User.find_for_database_authentication(:email => params[:email])
    return invalid_login_attempt unless resource

    if resource.valid_password?(params[:password])
        resource.ensure_authentication_token!  #make sure the user has a token generated
        render :json => { :authentication_token => resource.authentication_token, :user_id => resource.id }, :status => :created
        return
    end
end

def invalid_login_attempt
    warden.custom_failure!
    render :json => { :errors => ["Invalid email or password."] },  :success => false, :status => :unauthorized
end

The problem is that native devise sessions_controller#create looks like this

  def create
    self.resource = warden.authenticate!(auth_options)
    set_flash_message(:notice, :signed_in) if is_navigational_format?
    sign_in(resource_name, resource)
    respond_with resource, :location => after_sign_in_path_for(resource)
  end

And i don't know how to combine this two create methods to have authentication working on website and via json too?

UPDATE

The working code

def create
    respond_to do |format|

      format.json do
        build_resource
        resource = User.find_for_database_authentication(:email => params[:email])
        return invalid_login_attempt unless resource

        if resource.valid_password?(params[:password])
          resource.ensure_authentication_token!  #make sure the user has a token generated
          render json: { authentication_token: resource.authentication_token, user_id: resource.id }, status: :created
          return
        end
      end

      format.html do
        self.resource = warden.authenticate!(auth_options)
        set_flash_message(:notice, :signed_in) if is_navigational_format?
        sign_in(resource_name, resource)
        respond_with resource, :location => after_sign_in_path_for(resource)
      end

    end
  end

Answer 1

You want your SessionsController#create method to look something like this:

class Users::SessionsController < Devise::SessionsController
  def create
    resource = warden.authenticate!(scope: resource_name, recall: "#{controller_path}#new")
    set_flash_message(:notice, :signed_in) if is_navigational_format?
    sign_in(resource_name, resource)

    respond_to do |format|
      format.html do
        respond_with resource, location: redirect_location(resource_name, resource)
      end
      format.json do
        render json: { response: 'ok', auth_token: current_user.authentication_token }.to_json, status: :ok
      end
    end
  end
end 

...and make sure you've configured devise to use the token authentication key your clients will pass along.