[jQuery] AJAX download progress
I am trying to figure out a way of displaying how far along an AJAX
download is. Assuming I know the size of the file being downloaded
(this will require the server to send a content-length header) then if
I can check the number of bytes downloaded thus far I should be able
to work out the download progress.
So what I need to know, how can you get the value of the content-
length header if it is set, and how can you check the number of bytes
sent periodically? I can then display a percentage for the case where
both are known, or simply a count of downloaded bytes when I don't
know the content length.