app/controllers/application_controller.rb
class ApplicationController < ActionController::Base
# Prevent CSRF attacks by raising an exception.
# For APIs, you may want to use :null_session instead.
protect_from_forgery with: :exception
helper_method :current_channel
private
def current_channel
@current_channel ||= Channel.find(session[:channel_id]) if session[:channel_id]
end
end