humble bundle export download links to a list

humble-download-list.js

// ==UserScript==
// @name     humble export downloads as a text file
// @version  1
// @match    https://www.humblebundle.com/downloads*
// @grant    none
// @require https://cdnjs.cloudflare.com/ajax/libs/FileSaver.js/2.0.0/FileSaver.min.js
// ==/UserScript==
(function() {
  'use strict';

  function parseDownloadButtons() {
    var selector = '.download-rows .download a';
    var downloadButtons = document.querySelectorAll(selector);

    var links = [];

    for (var i = 0; i < downloadButtons.length; i++) {
      var btn = downloadButtons.item(i);
      var link = btn.href;

      if (link !== undefined && link !== null) {
        links.push(link);
      }
    }

    return links;
  }

  function exportAsList(desiredFileType) {
    var fileType = desiredFileType.toLowerCase();
    var links = parseDownloadButtons();

    if (desiredFileType !== undefined && desiredFileType !== null) {
      links = links.filter(function (link) {
        return link.indexOf(fileType) > 0;
      });
    }

    var content = links.join("\n");
    var txt = new Blob([content], { type: 'plain/text;charset=utf-8' });

    saveAs(txt, "humble-download-links.txt");
  }

  function ourDownloadButton() {
    var selector = '.js-all-downloads-holder .bulk-downloader';
    var typeSelector = 'select.js-file-type-select';

    var bulkDownloader = document.querySelector(selector);
    var select = document.querySelector(selector + ' ' + typeSelector);

    var fileType = select.value;

    var ourBtn = document.createElement('button');
    ourBtn.appendChild(document.createTextNode('Export as List'));

    ourBtn.addEventListener('click', function () {
      exportAsList(fileType);
    });

    bulkDownloader.appendChild(ourBtn);
  }

  // ready, set, go!
  var isRegistered = false;
  var run = setInterval(function () {
    // already there, don't keep running this please
    if (isRegistered) {
      return;
    }

    // keep checking for bulk downloader <div>
    var box = document.querySelector('.js-all-downloads-holder .bulk-downloader');
    if (box === undefined || box === null) {
      return false;
    }

    // once it's found register the button
    clearInterval(run);

    // set our excellent button
    ourDownloadButton();
    isRegistered = true;
  }, 500);
})();