[Catalyst] Detecting if a user aborted a (long) download

[Jeff Chimene]

Wade.Stuart at fallon.com wrote:
>
>
>   
>> Since we haven't heard from the OP. I have two questions:
>> o Did you investigate sendfile?
>>     
>
> Sendfile() buys you nothing relevant to the OP's question.
>   
Really? The OP was merely detecting whether or not the session aborted, 
not whether or not the file successfully downloaded. Apparently 
sendfile() can return an error condition related to the OP's original 
design.
>   
>> o Have you considered implementing a download progress indicator? One of
>> the reasons users give up on downloads is that they don't know what's
>> happening.
>>     
>
> What browser are you using that does not:
>
> 1, have its own download session manager + progress display
> 2, where download app continues download even if you leave the page/site
> that started it
> 3, and the browser tells you "hey numbnuts, you are still downloading are
> you sure you want to close?" when you try to close your browser before the
> download is complete.
> 4, where a separate download progress bar that is non standard would be
> anything but confusing to a user?
>
> The bottom line is, downloads break sometimes for many reasons.  Your app
> (being on the server) will never be able to know if the download completes
> or not unless you control the download end-to-end (such as writing and
> distributing your own download manager).  A silly progress bar embedded in
> your webapp does not get you past this problem.  A simple, smart and quite
> frankly the industry standard solution is to allow the user to try again on
> failure.
>   
It's not clear to me that the OP is using a browser, vs. some custom 
application that relies on HTTP protocol. Since the OP hasn't chimed in 
on this thread, I'm done answering these questions.