Auto WayBack - Load latest snapshot from Wayback Machine

autoWayBack.js

// ==UserScript==
// @name         Auto Wayback
// @namespace    http://tampermonkey.net/
// @version      3.1.1
// @description  Load latest snapshot from Wayback Machine
// @author       Piyush Singh
// @match        *://*/*
// @icon         data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==
// @grant        unsafeWindow
// ==/UserScript==

// To Use just press Ctrl+L and you will be redirected to Wayback URL.
// Can also be used from your browser console by `wayback()`


function wayback()
{
            var url = "https://archive.org/wayback/available?url="+document.URL;
            const xhr = new XMLHttpRequest();
            xhr.open("GET", url);
            xhr.send();
            xhr.responseType = "json";
            xhr.onload = () => {
            if (xhr.readyState == 4 && xhr.status == 200) {
                 console.log("valid");
                 console.log(xhr.response);
                 if (Object.keys(xhr.response.archived_snapshots).length==0)
                 {
                     window.alert("No snapshot found in Wayback Machine.");
                     return;
                 }
                 var wayback_url = xhr.response.archived_snapshots.closest.url;
                 window.location.replace(wayback_url);
             } else {
                 console.log(`Error: ${xhr.status}`);
             }
            };
}

(function() {
    'use strict';
    if(!unsafeWindow.wayback) unsafeWindow.wayback = wayback;
    document.onkeyup=function(ev){
        // var ev = ev || window.event; // for IE to cover IEs window object
        if(ev.ctrlKey && ev.which == 76) {
            wayback();
            return false;
        }
    }

})();