Custom Token Authentication SessionController with DRY Authenticatable Logout

create.json.jbuilder

json.success true
json.data do
  json.auth_token @user.authentication_token
  json.message "login successful"
end

destroy.json.jbuilder

json.success true
json.data do
  json.message "logout successful"
end

failure.json.jbuilder

json.sucess false
json.data do
  json.message "login failed"
end

sessions_controller.rb

class SessionsController < Devise::SessionsController
  skip_before_filter :verify_authenticity_token, if: :json_request?

  acts_as_token_authentication_handler_for User
  skip_before_filter :authenticate_entity_from_token!
  skip_before_filter :authenticate_entity!
  before_filter :authenticate_entity_from_token!, :only => [:destroy]
  before_filter :authenticate_entity!, :only => [:destroy]

  def create
    warden.authenticate!(:scope => resource_name, :recall => "sessions#failure")
    @user = current_user
    # renders destroy.json.jbuilder
  end

  def destroy
    @user = current_user
    @user.authentication_token = nil
    @user.save
    # renders destroy.json.jbuilder
  end

  def failure
    # renders failure.json.jbuilder
  end

  protected

  def json_request?
    request.format.json?
  end
end