FEATURE: export user list

app/controllers/admin/export_csv_controller.rb

@@ -0,0 +1,20 @@
+class Admin::ExportCsvController < Admin::AdminController
+
+  skip_before_filter :check_xhr, only: [:download]
+
+  def export_user_list
+    # export csv file in a background thread
+    Jobs.enqueue(:export_csv_file, entity: 'user', user_id: current_user.id)
+    render json: success_json
+  end
+
+  def download
+    filename = params.fetch(:id)
+    if export_csv_path = ExportCsv.get_download_path(filename)
+      send_file export_csv_path
+    else
+      render nothing: true, status: 404
+    end
+  end
+
+end