Set default value at backend side

app/assets/javascripts/admin/bulk_product_update.js.coffee

@@ -56,7 +56,7 @@ angular.module("ofn.admin").controller "AdminProductEditCtrl", ($scope, $timeout
       'q[name_cont]': $scope.query,
       'q[supplier_id_eq]': $scope.producerFilter,
       'q[primary_taxon_id_eq]': $scope.categoryFilter,
-      'q[s]': $scope.sorting || 'created_at asc',
+      'q[s]': $scope.sorting,
       import_date: $scope.importDateFilter,
       page: $scope.page,
       per_page: $scope.per_page

app/controllers/api/products_controller.rb

@@ -60,7 +60,7 @@ module Api
       end
 
       @products = product_query.
-        ransack(params[:q]).
+        ransack(query_params_with_defaults).
         result.
         page(params[:page] || DEFAULT_PAGE).
         per(params[:per_page] || DEFAULT_PER_PAGE)
@@ -142,6 +142,10 @@ module Api
       }.to_json
     end
 
+    def query_params_with_defaults
+      params[:q].to_h.reverse_merge!({ 's' => 'created_at DESC' })
+    end
+
     def pagination_data(results)
       {
         results: results.total_count,