You could either configure the defaultFileName initially or you could destroy and recreate the PDFViewer widget using the needed configuration. Here is a Dojo example where this is demonstrated.
I hope you will find the provided suggestion helpful.
any chances to have the filename changed in a more friendly way?
Neli
Telerik team
commented on 08 Sep 2021, 09:05 AM
Hi Aleksandr,
In case the defaultFileName is set on initialization of the PDFViewer there should be no issue and the PDFViewer functionalities should work as expected. However, setOptions as mentioned earlier is not suitable for changing all the configuration options of the widget. I am afraid it is not suitable for DefaultFileName as well and in case you need to change the DefaultFileName after initialization of the widget, you will need to use the approach described above.