Intercept/Overwrite Download Function in WebViewer

WebViewer Version: 8.10.0

We have the use case in which the pdftron WebViewer is running in a embedded Chromium instance (CEF) .
In this case, the build in download functionality failed (not implemented). But we have the possibility, to handle a download which a custom API.

Is it possible to intercept/overwrite the download/extract functionality?


Thank you for contacting WebViewer support.

There is an API called updateElement that you can use to override the onClick function of the download button.

You can call:

instance.UI.updateElement('downloadButton', {
    onClick: () => console.log('download button clicked'),

If you try the code above, you’ll notice that when you click on the download button, instead of making the download, it will just log a message. So, instead of the console.log, you’ll add your logic.


Dandara Navarro
Web Software Developer
PDFTron Systems, Inc.