How to prevent a shared document from downloading more than once?
Gary C Martin
gary at garycmartin.com
Mon Mar 16 15:45:11 EDT 2009
On 16 Mar 2009, at 15:29, James Simmons wrote:
> It looks like my last naive question about collaboration started a
> discussion so notable that Walter Bender wrote about it in his blog
> http://walterbender.org/. Let's see what you can do with this one.
> Both my Activities, Read ETexts and View Slides, have document sharing
> code mostly copied from the core Read activity. Currently this works
> just fine in both Activities, with only one problem. Suppose someone
> shares a document with me, I receive it successfully, then quit,
> the copied document to be saved in my Journal. Now if the original
> stops sharing (closes his copy of the Activity) and I resume mine I
> my stored copy and all is wonderful. But suppose the original user
> *doesn't* stop sharing. I resume my copy, see the stored copy on the
> screen, but I *still* download the document my friend is sharing. I
> don't want to do that. It wastes bandwidth and time and causes *keep*
> errors when you close the document.
> Now the problem is, the sharing code is in the __init__() method,
> always runs before anything else, and the read_file() method, which
> when you resume from the Journal, unfortunately *after* the Activity
> already decided it needs to download the file. I need a way for the
> __init__ method to realize that it doesn't need to download the
> file, or
> some other way to deal with the problem.
Sorry, I'm likely missing something obvious here, but could the
__init__() check to see if it was resumed from journal, and use that
as a cue to read the local file? If the file is incomplete/corrupt
you'd need back out and get the file remotely:
if handle.object_id == None:
# Launched from home.
# Journal resume, don't download, use local file.
P.S. This coming from a man who hasn't implemented collaboration in
any of his activities yet.
> James Simmons
> Devel mailing list
> Devel at lists.laptop.org
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