HTML5 notifications on Spotify Web Player

Adds silent song notifications with title, artist and cover art

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 or Violentmonkey 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        HTML5 notifications on Spotify Web Player
// @description Adds silent song notifications with title, artist and cover art
// @namespace   https://greasyfork.org/users/4813-swyter
// @match       https://play.spotify.com/*
// @version     2016.06.08
// @grant       none
// @noframes
// ==/UserScript==

/* run this just on the parent page, not in sub-frames */
if (window.parent !== window)
  throw "stop execution";

function when_external_loaded()
{
  /* request permission to show notifications, if needed */
  if (Notification.permission !== 'granted')
    Notification.requestPermission();

  /* create a listener mechanism for title changes using mutation observers,
     let's be good citizens (http://stackoverflow.com/a/29540461) */
  document.aptEventListener = document.addEventListener;
  document.addEventListener = function(what, callback)
  {
    if (what !== 'title')
      return document.aptEventListener.apply(this, arguments);

    console.log('setting title event listener =>', arguments);

    new MutationObserver(function(mutations)
    {
      console.log('mutation observer triggered =>', mutations[0].target);
      
      /* save the title also at trigger time, so that we can skip it if the song
         has quickly changed between the triggering and the notificaction shows up */
      setTimeout(
        callback.bind(this, document.title),
        4500
      );

    }).observe(document.querySelector('title'), {subtree: true, childList: true, characterData: true});
  };

  /* trigger a new notification every time the page title changes */
  document.addEventListener('title', function(title_when_triggered)
  {
    /* trigger it only if we are actually playing songs and we haven't
       shown a notification for this song already */
    if (!document.title.match('▶') || document.prevtitle === document.title || title_when_triggered !== document.title)
    {
      console.log('returning without showing it up =>', document.title);
      return;
    }

    /* save the current title to avoid needless repetition */
    document.prevtitle = document.title;

    /* some debug printing to help out development, seems work work pretty nicely */
    console.log('this seems to be a new song, showing it up =>', document.title);

    /* feel free to customize the formatting and layout to your liking */
    var track_name     = document.querySelector("iframe#app-player").contentWindow.document.querySelector("#track-name > a").textContent;
    var track_artist   = document.querySelector("iframe#app-player").contentWindow.document.querySelector("#track-artist > a").textContent;
    var track_coverart = document.querySelector("iframe#app-player").contentWindow.document.querySelector(".sp-image-img").style.backgroundImage.replace(/"/g,'').split("(")[1].split(")")[0];

    /* show it! */
    new Notification(track_name, {body: track_artist, icon: track_coverart, silent: true});
  });
}

/* inject this cleaning function right in the page to avoid silly sandbox-related greasemonkey limitations */
window.document.head.appendChild(
  inject_fn = document.createElement("script")
);

inject_fn.innerHTML = '(' + when_external_loaded.toString() + ')()';