Do you have automatic output buffering or gzipping turned on in PHP? 
We set $no_compress on downloads, but if you have it turned out at the 
PHP level we can't override it (afaik).



After thinking about this during a few days of downloading things, I 
am very much against an interim page by default, as it'd get really 
annoying. I can see it for large files and zipped downloads, as long 
as we can arrive at a reasonable definition of "large".



It might also be worth profiling view.php a little - Michael, any 
sense if there's easy improvements to squeeze out of that code?



Any other opinions here?

Either way would be a positive addition.  The goal is to give the user 
an indication that their file is downloading.  As it stands users tend 
to associate a spinning logo with nothing new on the screen as a 
stalled process and they immediately assume something is broken.

The thing we can control is what happens before we start sending data 
back to the client, which is probably the issue here. One thing is 
that if there's any sort of compression or output buffering, there'll 
be a wait until either all of the data or the first chunk is ready.



Another possibility would be to spool downloads to a temp file and 
then redirect so the download when it's ready. That's probably not 
better. We could also have some sort of sourceforge-like "your 
download will begin shortly..." page (or javascript layer).

I'm not 100% sure either.  However IMHO it's not good design to just 
have the page sitting there doing what appears to be nothing for 
several minutes.  Thus at the very least there should be a message 
somewhere that says that the file is downloading and it can take 
several minutes depending on the size of the file.  I think that would 
go a long way towards reassuring users that nothing has broken

We have no influence on how the browser visualizes a file download, 
let alone that we could get this information from the browser and 
display it in the IMP interface. I have no idea how you want to 
achieve this.

Currently when downloading large (10 MB+) attachments once the user 
has clicked on the link the browser just sits there spinning for 
several minutes, presumably transferring the attachment to the browser 
cache, before getting a popup asking you where you want to save the 
attachment.  The problem is that there's no progress indicatior.  In 
fact, there's no notice whatsoever that something's actually 
happening.  Thus our users have been erroneously assuming that there's 
a problem or something's "stuck" and hit the stop button, never 
actually receiving the attachment... and then promptly complaining to 
us.



What I'd like to see is at bare minimum there be a message of some 
sort telling the user that the attachment is downloading (a time 
estimate would be nice - especially for larger files).  Ideally a 
progress bar would appear somewhere to let users know that something's 
actually happening.  I'm not sure how feasible that is (it might be 
easier with Dimp) but it would alleviate a LOT of grief from our help 
desk since that's one of the more frequent complaints we get.