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RE: HREF Property in Thai Restaurant

From: Jim Davis <jrd3@alum.mit.edu>
Date: Sun, 21 Nov 1999 23:57:39 +0100
Message-Id: <4.1.19991121234319.00af9de0@pop.xs4all.nl>
To: "WWW WebDAV DASL (E-mail)" <www-webdav-dasl@w3.org>
At 05:18 PM 11/21/99 +0000, Mark Birbeck wrote:
>Jim Davis wrote:
>> Adding a new review is done by first PUTting a new resource, 
>> then setting some properties on it with PROPPATCH.  You can
>> get all the data by doing a PROPFIND, and you search by doing
>> a SEARCH.  
>> 
>> On such a server, you certainly want access control (so that 
>> only the one who creates the review can change it) and you also
>> want locking (so that if two different people both want to add
>> a new review at the same time, they see a consistent world)
>
>OK - but where are the locks for these reviews? Don't the locks on the
>'good-eating.com' server refer to the URI in the review - that is, the
>restaurant web site? And you can't lock that because it is not in your
>control.

No, not at all.  When you lock  a resource (eg http://good-eating.com/i274) you
prevent anyone else from changing the state of that resource.  The state of a
resource includes at least its properties and perhaps also its "content" (in
the simple cases, the contents of a resourc is just the file that's associated
with it, but this is tricky in tricky cases where the resource is dynamic.  but
we dont need to go into those tricky cases.)

So suppose the resource whose URI is  http://good-eating.com/i259 

has the properties and contents shown
    +----------------------------------------------- 
     | rating: 4 stars 
     | reviewed by: Dave Fielding 
     | review of: http://www.siamiam.com 
     | date: 19-11-1999 
     | review number 259
    +-------------
     | this is the best pad thai ever....
    +------------

Then when you lock it, no one else can change the rating, the reviewed by, or
the URI of the site you reviewed.  (e.g to make it point somewhere else)  .
But you have no lock on http://www.siamiam.com itself.  That web site could
totally change, and you could not do anything about it.

>Although you said my scenario was 'unnecessarily complicated', it's the
>only solution I can see - that is, to introduce another WebDAV server
>(or a new container within the review server) that contained references
>to the reviews on the good-eating.com server you just described. *Then*
>you can have locking on the reviews, and then you can search for
>"reviews that are currently locked by Jim", or were "created yesterday".
>If you query for "created yesterday" on good-eating.com, don't you get
>back restaurant web sites that were created yesterday, not reviews that
>were written yesterday

No, not at all.

if this still does not make sense to you I think you need to draw a picture or
something.
sorry to be so bad at explaining all this.
Received on Sunday, 21 November 1999 17:59:20 GMT

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