Storing staticfiles on a separate subdomain

Technical Support
3

I found this article which discusses another way to get around cross-origin if you’re still on the same domain (vs subdomain):

I created copies of the four linked javascript files and added document.domain = 'mydomain.com' to them.

I modified my viewer to look like this:

<!doctype html>
<html moznomarginboxes mozdisallowselectionprint>

<head>
  <base href="{% static 'pdfjsexpress/public/ui/' %}">
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no">
  <link rel="stylesheet" href="style.css">
  <title>WebViewer UI</title>
</head>

<body>
  <div id="app"></div>
  <div id="line-connector-wrapper">
    <div id="line-connector-root"></div>
  </div>
  <script>
    // Proxy whether we're running in production and set the domain to enable cross origin iframe access
    // https://pdfjs.community/t/storing-staticfiles-on-a-separate-subdomain/828
    // https://stackoverflow.com/questions/3076414/ways-to-circumvent-the-same-origin-policy
    if (window.location.href.startsWith('https')) {
      document.domain = 'onuptick.com'
    }
  </script>
  <script src="../core/CoreControls.crossdomain.js"></script>
  <script src="../core/pdfjs/PDFJSDocumentType.crossdomain.js"></script>
  <script src="../core/pdfjs/UIConfig.crossdomain.js"></script>
  <script src="webviewer-ui.min.crossdomain.js"></script>
</body>

</html>

And added this useEffect into my react component just before the useEffect call to initialise the WebViewer:

  useEffect(() => {
    if (crossOrigin) {
      document.domain = 'onuptick.com'  // https://stackoverflow.com/questions/3076414/ways-to-circumvent-the-same-origin-policy
    }
  })

However, this didn’t work. I get the same error.

So I looked at the iframe src that the pdfjs.express library was creating, and opened that in a tab directly to eliminate the cross tab communication and see whether the error remains. So to be clear that means I’ve got a tab open that is the /core/ui/index.html with the #d= pointing to a PDF file.

I get the same result “Error: Setting up fake worker failed: “Cannot read property ‘WorkerMessageHandler’ of undefined”.”

So the error is happening in PDF.js / Express somewhere, not the interframe communication.

This means the links you’ve posted aren’t relevant as I can’t use postMessage (because there’s no frame involved). It’s just that the /ui/index.html is on a different domain to the scripts it’s loading (because staticfiles are hosted on a different subdomain).

Any ideas?