Tandro.de - Close Confirmation Prompt

Warns you before accidentally closing or reloading tandro.de

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install an extension such as Tampermonkey or Violentmonkey to install this script.

You will need to install an extension such as Tampermonkey or Userscripts to install this script.

You will need to install an extension such as Tampermonkey to install this script.

You will need to install a user script manager extension to install this script.

(I already have a user script manager, let me install it!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         Tandro.de - Close Confirmation Prompt
// @namespace    http://tampermonkey.net/
// @version      1.1
// @description  Warns you before accidentally closing or reloading tandro.de
// @author       Asriel
// @license      GPL-3.0
// @icon         https://tandro.de/img/logo_small_4.png
// @match        *://tandro.de/*
// @match        *://www.tandro.de/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';

    window.addEventListener('beforeunload', function(e) {
        const confirmationMessage = 'Bist du sicher, dass du die Seite verlassen möchtest? Deine Änderungen könnten verloren gehen.';
        (e || window.event).returnValue = confirmationMessage; // For older browsers
        return confirmationMessage;
    });
})();