RE: Global Properties

The concept of global properties is not defined in the protocol,
so either your clients or your servers (or both) will need to 
adopt some non-standard convention to support the concept.

An advantage of the "VHR property" approach is that only the clients
need to understand the convention (you can use standard DeltaV servers).
An advantage of the attribute approach you describe below is that
any client can see the global properties (but only special servers
can be used).  So either approach has its advantages and disadvantages.

Cheers,
Geoff

-----Original Message-----
From: John Hall [mailto:johnhall@xythos.com]
Sent: Wednesday, September 12, 2001 6:28 PM
To: ietf-dav-versioning@w3.org
Subject: Global Properties




> Your client can present any model that it wants, but to 
> interoperate with multiple servers, it needs to adhere to the 
> DeltaV semantics, in which the VCR and VHR are separate 
> resources with their own locks. Similarly, your client can do 
> whatever it wants in terms of displaying a global property 
> model, but to provide an interoperable form, it must use 
> DeltaV/WebDAV compatible requests (such as modeling global 
> properties as properties of the shared VHR).


'Modeling' global properties as properties of the VHR in such a system
is necessarily a proprietary design.  It is simpler to just say that
DeltaV does not provide global properties, period.

For properties to be global, I have to be able to get them by doing a
propfind on the VCR or any particular VERSION.  If I have to go to two
completely different places with two completely different requests, then
they are not behaving as global properties.  Pretending that they are
would only confuse people.

=====================

Global Properties are still useful, though.  But the only real way I can
see them being implemented is adding something like a scope attribute to
the prop element like:

<property-update>
  <prop scope=global>
     <globalprop1>foo</globalprop1>
  </prop>
</property-update>

============================

I assume that servers that don't support global properties would just
ignore the scope attribute.

Received on Wednesday, 12 September 2001 22:48:30 UTC