a js script to embed spotify playlists or albums when a spotify share url is present

spotify-embed.user.js

// ==UserScript==
// @name         spotify embedder
// @version      1
// @namespace    https://gist.github.com/chadlavi/eba2e3420fb9c1a6a891f8ed2c29e2ae
// @downloadURL  https://gist.github.com/chadlavi/eba2e3420fb9c1a6a891f8ed2c29e2ae/raw/spotify-embed.user.js
// @updateURL    https://gist.github.com/chadlavi/eba2e3420fb9c1a6a891f8ed2c29e2ae/raw/spotify-embed.user.js
// @description  embed spotify player when a url is present
// @author       Chad Lavimoniere
// @exclude      http*://*youtube.com*
// @exclude      http*://*facebook.com*
// @exclude      http*://*twitter.com*
// @exclude      http*://mltshp.com*
// @exclude      http*://news.ycombinator.com*
// @include      http*://*.*
// @grant        none
// ==/UserScript==

// playlist link pattern:
// https://open.spotify.com/user/[user]/playlist/[id]

// album link pattern:
// https://open.spotify.com/album/[id]

// embed pattern:
//<iframe src="https://open.spotify.com/embed?uri=spotify:[album/playlist]:[id]" width="300" height="380" frameborder="0" allowtransparency="true" allow="encrypted-media"></iframe>

(function() {
  'use strict';

  function create(htmlStr) {
    var frag = document.createDocumentFragment(),
        temp = document.createElement('div')
    temp.innerHTML = htmlStr
    while (temp.firstChild) {
      frag.appendChild(temp.firstChild)
    }
    return frag;
  }
  
  function spotifyPlaylistEmbed(link) {
    var url = link.href.replace(/\?.*/, '')
    var playlistId = url.replace(/https?:\/\/open\.spotify\.com\/user\/[^\/]*\/playlist\//, '')
    var embed = create('\<br>\
<iframe src="https://open.spotify.com/embed?uri=spotify:playlist:' + playlistId + '" width="300" height="380" frameborder="0" allowtransparency="true" allow="encrypted-media"></iframe>\
<br>')
    link.parentNode.insertBefore(embed, link)
  }
  
    function spotifyAlbumEmbed(link) {
    var url = link.href.replace(/\?.*/, '')
    var albumId = url.replace(/https?:\/\/open\.spotify\.com\/album\//, '')
    var embed = create('\<br>\
<iframe src="https://open.spotify.com/embed?uri=spotify:album:' + albumId + '" width="300" height="380" frameborder="0" allowtransparency="true" allow="encrypted-media"></iframe>\
<br>')
    link.parentNode.insertBefore(embed, link)
  }

  var links = document.links
  for (var i=0; i<links.length; i++){
    var link = links[i]
    if (link.href.match(/https?:\/\/open\.spotify\.com\/user\/[^\/]*\/playlist/g)){  
      spotifyPlaylistEmbed(link)
    } 
    
    if (link.href.match(/https?:\/\/open\.spotify\.com\/album/g)){  
      spotifyAlbumEmbed(link)
    } 
  }
})();