Refactor datatable class to a controller concern

app/controllers/admin/users_controller.rb

@@ -1,16 +1,19 @@
 module Admin
   class UsersController < Admin::BaseController
     load_and_authorize_resource
+    include DatatableServersideProcessing
 
     def new
       @user = User.new
     end
 
     def index
-      users_datatable = Datatable.new(view_context, User.where(nil), %w(name email), %w(id state email name))
+      @users = filtered_records(User.where(nil), %w(name email), %w(id state email name))
       respond_to do |format|
         format.html
-        format.json { render json: users_datatable.to_json(data: users_datatable.paginated_records.map {|user| users_datatable_data(user)}) }
+        format.json do
+          render json: datatable_response(@users.map {|user| users_datatable_data(user)})
+        end
       end
     end
 

app/controllers/concerns/datatable_serverside_processing.rb

@@ -1,23 +1,19 @@
-class Datatable
+module DatatableServersideProcessing
-  delegate :params, to: :@view
+  extend ActiveSupport::Concern
 
-  def initialize(view, collection, search_columns, sort_columns)
+  def datatable_response(data)
-    @view = view
-    @collection = collection
-    @search_columns = search_columns
-    @sort_columns = sort_columns
-  end
-
-  def as_json(options={})
     {
       sEcho: params[:sEcho].to_i,
       iTotalRecords: @collection.count,
       iTotalDisplayRecords: records.count,
-      aaData: options[:data]
+      aaData: data
     }
   end
 
-  def paginated_records
+  def filtered_records(collection, search_columns, sort_columns)
+    @collection = collection
+    @search_columns = search_columns
+    @sort_columns = sort_columns
     paginate(records)
   end
 
@@ -31,12 +27,12 @@ class Datatable
     sort_direction = params[:sSortDir_0] == 'desc' ? 'desc' : 'asc'
     sort_column = @sort_columns[params[:iSortCol_0].to_i]
     records = @collection.order("#{sort_column} #{sort_direction}")
+
     if params[:sSearch].present? && @search_columns.present?
-      search_query = ''
+      search_query = @search_columns.map{ |column|  "#{column} like :search" }.join(' or ')
-      @search_columns.each { |column| search_query += "#{column} like :search or " }
-      search_query = search_query.chomp(' or ')
       records = records.where(search_query, search: "%#{params[:sSearch]}%")
     end
+
     records
   end