FB Instant Articles: Can i display a PDF file inside an instant article?

I'm new to facebook instant articles. I have a website that depends on PDF files to represent political researches, each article (page) on the website contains a PDF file inside. Is there a way to display a PDF file inside the instant article?

Instant Articles does not support PDF's as a format. You can see all the supported formats here BUT you should still be able to display a pdf as an op-interactive(Embed). See the documentation here: https://developers.facebook.com/docs/instant-articles/reference/embeds

It's basically just an iframe to which you can either add the js script inline or point to a hosted page that uses something like pdf.js, for example.

Here are some examples assuming pdf.js:

Embedded op-interactive (untested, grabbed from their github docs):

<figure class="op-interactive">
    <iframe>
        <script>
            var url = './helloworld.pdf';
            PDFJS.workerSrc = 'http://yourdomain.com/build/pdf.worker.js';
            PDFJS.getDocument(url).then(function getPdfHelloWorld(pdf) {
                pdf.getPage(1).then(function getPageHelloWorld(page) {
                    var scale = 1.5;
                    var viewport = page.getViewport(scale);
                    var canvas = document.getElementById('the-canvas');
                    var context = canvas.getContext('2d');
                    canvas.height = viewport.height;
                    canvas.width = viewport.width;
                    var renderContext = {
                        canvasContext: context,
                        viewport: viewport
                    };
                    page.render(renderContext);
                });
            });
        </script>
    </iframe>
</figure>

URL based op-interactive:

<figure class="op-interactive">
  <iframe src="https://yourdomain.com/pdfembed.html" width="600" height="600"></iframe>
</figure>

There really wouldn't be any other way to do it at this time.