Piwik not recording javascript getpdf

I have a javascript call getpdf to download some pdf when the link is clicked. It seems that piwik is not recording those in the download section. Is this just a limit or can I tweak something to get those recorded?

JavaScript links are ignored. If your script causes a download, then call trackLink().

Thanks for the information. Since, where would you call the trackLink(). Can you give an example?