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RE: Core versioning issues and nits

From: Lisa Dusseault <lisa@xythos.com>
Date: Mon, 5 Feb 2001 14:58:35 -0800
To: "Geoffrey M. Clemm" <geoffrey.clemm@rational.com>, <ietf-dav-versioning@w3.org>
Message-ID: <CNEEJCPIOLHKIOFNFJDPGEBMCDAA.lisa@xythos.com>
>
>    I agree that determining type by the absence of properties is
>    sub-optimal; I'd say it's not very reliable.
>
> How is it any less reliable than looking for a particular value
> in a "resourcetype" property?

A particular value on a particular property can be preserved even when
the protocol changes (whether the protocol is changing as a result of
sanctioned IETF activity or independent vendor activity).  Also, a
particular value on a particular property is less likely to appear "by
accident".

In contrast, the absence of a property is less likely to be preserved
when extending the protocol: somebody will come up with a new useful
value for the property, and break clients that relied on that property
being absent.  Or, on an non-versioning server like IIS 5.0 that
supports dead properties, somebody could set the "DAV:checked-in"
property to ANY value, and no matter what value it's set to, it risks
breaking clients that look for that property.

I'm not saying this is broke (particularly if the DAV:supported-methods
comes back as a property).  It's just not as reliable as I would prefer.

Lisa
Received on Monday, 5 February 2001 17:59:42 GMT

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