How to programmatically use pdf.js

[lfoppiano]

Hi, I'm trying to figure out how to use pdf.js in a programmatic way (without using the viewer wrappers that are provided in the project). The most comprehensive guide I found is here: https://www.sitepoint.com/custom-pdf-rendering/#renderingtextlayers however it seems outdated.

In particular:

1. the TextLayerBuilder constructor does not seems to be used correctly

      var textLayer = new TextLayerBuilder({
      textLayerDiv: textLayerDiv, 
      pageIndex: page.pageIndex,
      viewport: viewport
       });

2. The textLayer.setTextcontent() seems to be outdated too, I found only setTextContentSource() which did not work

    textLayer.setTextContent(textContent);
   
    // Render text-fragments
    textLayer.render();

I did not find much around, just a lot of old issues, but nothing really up-to-date.

I'm working on a streamlit pdf plugin that uses pdf.js https://github.com/lfoppiano/streamlit-pdf-viewer and I'm trying to enable the textLayer on it in this branch, if you need to see some code: https://github.com/lfoppiano/streamlit-pdf-viewer/tree/enable-text-content

[lfoppiano]

For information, I found a partial solution to my problem in #18068, however we are still not able to have a functioning application. I hope to get some hints by more knowledgeable people around here.
Thank you in advance