Subject: Re: Lock

From: Jim Whitehead <[email-masked]>
Date: Tue, 8 Feb 2000 18:24:08 -0800

Accidentally caught by the spam filter.

- Jim

-----Original Message-----
From: Barry Schaeffer [mailto:[email-masked]]
Sent: Tuesday, February 08, 2000 1:07 PM
To: [email-masked]
Subject: [Moderator Action] Re: Lock

This is perhaps somewhat afield from the current thread of discussion and
design but having monitored the colloquy over the past several weeks, I am
impelled to hazard a comment.

I have, over the past number of years, had the opportunity to see the
sometimes wide difference between what very intelligent standards developers
can reason out, and what often overworked, underfunded production
organizations can understand and use.  At times, the difference has been so
great that the standard never achieved working status because no-one in the
field felt responsible to spend the time or money to build a production
environment upon it.  DSSSL is a good example; extremely elegant but after
nearly 15 years, never moving into the mainstream.  Even XML has spawned
SML, a reaction against perceived over-complexity.  Moreover, the software
community nearly always indulges in a certain level of summarization in what
they elect to support (indeed, often the firms that go the  farthest toward
full compliance have the most troulble selling their wares with the
inevitiable negative result.)

While I am in no way qualified to question the efficacy of anything passing
in this thread, I am getting the feeling that the nuance of design embodied
in the current efforts may have the effect of making the target users feel
inadequate to understand or leverage the standard and the software vendors
unwilling to fully step up to the bar of support.

Let me, then, merely suggest that in each of these threads, a certain
capping of the capability (and complexity) might be appropriate.  If the
user world needs more than is initially made available, they will ask and
the standards community will, I'm sure, respond effectively.  But going too
far initially is usually a good way to become a footnote.

Best regards,

Barry Schaeffer
X.Systems, Inc.

----- Original Message -----
From: <[email-masked]>
To: <[email-masked]>
Sent: Tuesday, February 08, 2000 4:41 PM
Subject: Re: Lock

> Ok... But the real issue is if I can make sure that the Lock command tells
me,
> if I'm trying to lock something that has been updated. There is nothing in
the
> webdav spec. that specifies this behaviour, right? Can I even rely on that
if I
> send the E-tag, that the server is supporting this behavour on a Lock
command?
> ( this maybe applies to some other commands to... )
> If the resource is changed, what reply can I expect from the server?
>
> /Rickard
>
> >
> > I would like to voice *very* strong support for Greg's suggestion.  In
> > the presence of versioning, date comparisons such as "Last-Modified"
> > or "If-Unmodified-Since" do not provide you with reliable information
> > about the accuracy of what you have in your cache.  In particular, if
> > an older revision is made the default revision of a versioned
> > resource, it will have an older date, but your cache should be updated
> > with that older value.
> >
> > So ETag values should be the only ones you use to verify that you are
> > seeing the current value of a resource.
> >
> > Cheers,
> > Geoff
> >
> >    Date: Tue, 8 Feb 2000 03:34:19 -0800 (PST)
> >    From: Greg Stein <[email-masked]>
> >
> >    On Tue, 8 Feb 2000, Rickard Falk wrote:
> >    > I have another 'client side' related question.
> >    > When I'm issuing a Lock command, can I include the
'If-Unmodified-Since'
> in
> >    > the header ( http standard parameter...)?
> >    > In our client a user can browse through allot of files, without
having
> them
> >    > locked. Then when he wants to edit the file, he then presses a lock
> button.
> >    > But when he presses this button, the client must make sure that the
file
> >    > that he has read, is the latest one. Today I'm doing a Lock, then a
Head
> >    > command to se if the 'Last-Modified' parameter is changed since the
Get.
> It
> >    > would be much easier if I just could add the 'If-Unmodified-Since'
in the
> >    > Lock request.
> >
> >    You should be able to use If-Unmodified-Since (mod_dav will check for
it).
> >
> >    Note that you could also use ETag values to check for changes. I
think the
> >    ETag is probably the Right Way to look for possible changes on the
server.
> >
> >    Cheers,
> >    -g
> >
> >    --
> >    Greg Stein, http://www.lyra.org/
> >
> >
>
>