loads all jpegs and makes a pdf with them

scribd2pdf.js

load = async (url) => {
  var head= document.getElementsByTagName('head')[0];
  var script= document.createElement('script');
  script.type= 'text/javascript';
  script.src= url;
  return new Promise(resolve => {
    script.addEventListener('load', resolve);
    head.appendChild(script);
  });
}

getDataUri = async (url) => {
    var image = new Image();
    image.crossOrigin = "Anonymous";

    return new Promise(resolve => {
      image.onload = function () {
        var canvas = document.createElement('canvas');
        canvas.width = this.naturalWidth; // or 'width' if you want a special/scaled size
        canvas.height = this.naturalHeight; // or 'height' if you want a special/scaled size

        canvas.getContext('2d').drawImage(this, 0, 0);

        // ... or get as Data URI
        resolve(canvas.toDataURL('image/png'));
      };
      image.src = url;
    });

}

begin = async () => {
  console.log('Loading libraries')
  await Promise.all([
    load('https://github.com/devongovett/blob-stream/releases/download/v0.1.3/blob-stream.js'),
    load('https://github.com/devongovett/pdfkit/releases/download/v0.8.0/pdfkit.js'),
  ]);
  console.log('Initing PDF')
  const doc = new PDFDocument({
    size: 'a4',
    autoFirstPage: false,
  });
  const stream = doc.pipe(blobStream());
  stream.on('finish', () => {
    url = stream.toBlobURL('application/pdf');
    window.open(url, "zhe book");
    console.log('Popup should have opened now.');
  });

  const promises = [];
  const addImage = async (imgEl) => {
    const i = promises.length;
    await Promise.all(promises);
    if (imgEl && imgEl.src) {
      console.log('adding page', i);
      const uri = await getDataUri(imgEl.src);
      doc.addPage().image(uri, 0, 0, {
        fit: [600, 780],
        align: 'center',
        valign: 'center'
      });
    } else {
      doc.addPage();
      console.log('page empty', i)
    }
  };
  let pageEls = document.querySelectorAll('.outer_page');
  for (pageEl of pageEls) {
    const i = promises.length;
    console.log('loading page', i);
    pageEl.scrollIntoView();
    let imgEl;
    const startT = Date.now();
    while (!imgEl && (Date.now() - startT < 5000)) {
      await new Promise(r => setTimeout(r, 10));
      imgEl = pageEl.querySelector('.absimg');
    }
    promises.push(addImage(imgEl));
  }
  console.log('waiting for page', promises.length);
  await Promise.all(promises);
  console.log('Making PDF');
  doc.end();
}

begin();