File cleanup/organization in controllers/concerns (#27846)

app/controllers/concerns/settings/export_controller_concern.rb

@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+module Settings::ExportControllerConcern
+  extend ActiveSupport::Concern
+
+  included do
+    before_action :authenticate_user!
+    before_action :load_export
+
+    skip_before_action :check_self_destruct!
+    skip_before_action :require_functional!
+  end
+
+  private
+
+  def load_export
+    @export = Export.new(current_account)
+  end
+
+  def send_export_file
+    respond_to do |format|
+      format.csv { send_data export_data, filename: export_filename }
+    end
+  end
+
+  def export_data
+    raise 'Override in controller'
+  end
+
+  def export_filename
+    "#{controller_name}.csv"
+  end
+end