Download Slideshare slide sets for which saving has been disabled

ripslides.js

// Browser must be ignoring CORS
//  Chrome: Disable web security
//  Firefox: Requires proxy or Cors Everywhere extension (https://github.com/spenibus/cors-everywhere-firefox-addon)

function loadScript(url, callback)
{
    // Adding the script tag to the head as suggested before
    var head = document.getElementsByTagName('head')[0];
    var script = document.createElement('script');
    script.type = 'text/javascript';
    script.src = url;

    // Then bind the event to the callback function.
    // There are several events for cross browser compatibility.
    script.onreadystatechange = callback;
    script.onload = callback;

    // Fire the loading
    head.appendChild(script);
}

function downloadslide(zip, slides, number, cb) {
  var slide = slides[number];
  var slideurl = slide.children[0];
  if(slideurl.tagName.toLowerCase() !== "img")
    slideurl = slide.children[1];
  slideurl = slideurl.getAttribute("data-full");
  
  if(slideurl !== undefined && slideurl !== null) {
    JSZipUtils.getBinaryContent(slideurl, function(err, data) {
      if(err) {
        console.error("Slide download error: " + slideurl);
      } else {
        cb(data, number);
      }
    });
  }
}

loadScript("https://raw.githubusercontent.com/Stuk/jszip/master/dist/jszip.min.js", function() {
  loadScript("https://raw.githubusercontent.com/eligrey/FileSaver.js/master/FileSaver.min.js", function() {
    loadScript("https://raw.githubusercontent.com/Stuk/jszip-utils/master/dist/jszip-utils.min.js", function() {
      var slides = document.getElementsByClassName("slide");

      var zip = new JSZip();
      
      var schedslide = function(i) {
        downloadslide(zip, slides, i, function(data, i) {
          console.log("Got slide " + i);
          zip.file("slide" + i + ".jpg", data, {binary:true});
          if(i == slides.length - 1) {
            console.log("Saving zip");
            var content = zip.generate({type : "blob"});
                saveAs(content, document.title + ".zip");
          }
          else
            schedslide(i + 1);
        });
      }
      
      schedslide(0);
    })
  })
});