https://medium.com/p/e538ed6567a6

breadth-first-analytics.rb

# Read about this technique here:
# https://medium.com/p/e538ed6567a6

class ApplicationController < ActionController::Base
  after_filter :track_event

  private

  EVENT_TRANSLATIONS = {
   'users#create' => 'User Created',
   'users#update' => 'User Updated',
   'orders#new' => 'Order Started',
   'orders#create' => 'Order Created',
   'orders#update' => 'Order Updated'
  }  

  def track_event
    mixpanel.track(event_user, event_name, event_properties)
  end

  def event_properties
    {}
  end

  def event_user
    current_user.try(:id).to_s
  end

  def event_name
    controller_action = "#{params[:controller]}##{params[:action]}"
    EVENT_TRANSLATIONS[controller_action] || controller_action
  end  
end

class OrdersController < ApplicationController
  private

  def event_properties
    { quantity: @order.quantity, meal_name: @order.meal.name }
  end
end