I have a web application where the user can generate PDF and PowerPoint files. These files may take some time to generate, so I would like to be able to display a loading animation while it generates. The problem here is that I have no mean to know when the download has started. The animation never goes away.
I am aware that it could be possible to generate the file on the side and alert the user when the file is ready for download using AJAX, but I prefer locking the user while he waits for the download to start.