I have defined method in ApplicationController
class ApplicationController < ActionController::Base
helper_method :get_active_gateway
def get_active
Why would you need such thing? The model should not know about its controllers. Maybe a redesign of your system will be more appropriate in this case.
Here is a link to similar thread.
As a design choice, its not recommended to call controller helpers from your models.
You can just simply pass the required details to your model methods as arguments.
def transfer(active_gateway) active = active_gateway end