example of usage of a service in a controller

store_tracking.rb

# app/services/store_tracking.rb
# service that tracks user visits to a store, and keeps counters in the models
class StoreTracking

  def initialize(store, user, request)
    @store = store
    @user = user
    @request = request
  end
  
  def track
    RestClient.post "trackings/store/#{@store.id}", { user_id: @user.id, ip: @request.ip }
    @store.increment! :visits_count
    @user.increment! :visits_count
  end
end

stores_controller.rb

# app/controllers/stores_controller.rb
StoresController < ApplicationController
  before_action :find_store

  def show
    StoreTracking.new(@store, current_user, request).track
  end

  private

  def find_store
    @store = Store.find params[:id]
  end
end