analytics_worker.rb

#app/workers/analytics_worker.rb
##
# A Sidekiq worker that handles sending order data to Analytics
# Measurement Protocol

class AnalyticsWorker
  include Sidekiq::Worker
  sidekiq_options retry: 2
  
  def perform(id)
  	Order.find(id).send_to_ga
  end
end

line_item.rb

class LineItem < ActiveRecord::Base

  belongs_to :order
  
  ##
  # Sending subscription to GA https://developers.google.com/analytics/devguides/collection/protocol/v1/devguide#ecom
  # v=1               // Version.
  # &tid=UA-XXXXX-Y   // Tracking ID / Property ID.
  # &cid=555          // Anonymous Client ID.
  
  # &t=item           // Item hit type.
  # &ti=12345         // Transaction ID. Required.
  # &in=sofa          // Item name. Required.
  # &ip=300           // Item price.
  # &iq=2             // Item quantity.
  # &ic=u3eqds43      // Item code / SKU.
  # &iv=furniture     // Item variation / category.
  def send_to_ga
  	url = "https://www.google-analytics.com/collect?v=1&t=item&tid=#{GA_ID}&cid=#{order.ga_id}&ti=#{order_id}&in=#{ga_name}&ip=#{revenue}&iq=1&ic=#{provider.try(:id)}&iv=#{service_type.try(:name)}"
  	RestClient.post(url, {})
  end
end

order.rb

class Order < ActiveRecord::Base
  
  after_commit :queue_ga_worker
  has_many :line_items
  
  ##
  # Queue sidekiq worker to perform task of sending orders and subscriptions
  # to Google Analytics
  def queue_ga_worker
  	AnalyticsWorker.perform_async(id)
  end
  
  ##
  # Send order to GA Measurement Protocol
  # https://developers.google.com/analytics/devguides/collection/protocol/v1/devguide#ecom
  def send_to_ga
  	return nil unless ga_id
  	return nil unless completed?
  	ga_transaction_req
  	line_items.each(&:send_to_ga)
  	return true
  end
  
  ##
  # https://developers.google.com/analytics/devguides/collection/protocol/v1/devguide#ecom
  # v=1               // Version.
  # &tid=UA-XXXXX-Y   // Tracking ID / Property ID.
  # &cid=555          // Anonymous Client ID.
  # &t=transaction    // Transaction hit type.
  # &ti=12345         // transaction ID. Required.
  # &ta=westernWear   // Transaction affiliation.
  # &tr=50.00         // Transaction revenue.
  # &ts=32.00         // Transaction shipping.
  # &tt=12.00         // Transaction tax.
  # &cu=EUR           // Currency code.
  def ga_transaction_req
  	url = "https://www.google-analytics.com/collect?v=1&t=transaction&tid=#{GA_ID}&cid=#{ga_id}&ti=#{id}&tr=#{revenue}"
  	RestClient.post(url, {})
  end
end