order city on top page

app/controllers/tops_controller.rb

 class TopsController < ApplicationController
   def index
-    @vn_cities = City.vn_cities
+    @vn_cities = City.city_order.take(Settings.top.city.limit)
     @industries  = Industry.all
     @jobs = Job.page(params[:page]).per(Settings.job.per_page)
   end

app/models/city.rb

@@ -23,4 +23,8 @@ class City < ApplicationRecord
   def job_count
     @job_count ||= jobs.count
   end
+
+  def self.city_order
+    @city_order ||= all.sort_by(&:job_count).reverse
+  end
 end

config/settings.yml

@@ -3,3 +3,7 @@ job:
 
 csv:
   file_path: "jobss.csv"
+
+top:
+  city:
+    limit: 9