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Re: A REST challenge

From: Paul Prescod <paul@prescod.net>
Date: Tue, 16 Jul 2002 13:10:54 -0700
Message-ID: <3D347DCE.3BD077E1@prescod.net>
To: Francis McCabe <fgm@fla.fujitsu.com>, www-ws-arch@w3.org
CC: Mark Baker <distobj@acm.org>

Francis McCabe wrote:
> 
>...
> 
> Think a little about it. You are building a single system that is
> simultaneously maintaining a server presence and acting as a user agent.
> The two facets need to be coordinated; if you want the left hand to know
> what the right hand is doing.

Let's be concrete.

POST /call-back/server/
callback-URI: http://www.myhomeaddress.com/myuri/CORRELATIONID_1234

Now the call-back server calls back

POST /myuri/CORRELATIONID_1234
host: www.myhomeaddress.com

Note that the user agent can embed *as much* information in this URI as
it needs to recognize the appropriate callback. In fact, however, the
original POST could have also supplied all sorts of correlating
information in the body.

How would you do this otherwise with SOAP?

> This was the motivation in suggesting that an identity was necessary in
> maintaining a permanent presence in P2P style interactions.

Even if you were right that identity was important (which in some cases
it is, and some it isn't), identity can be established easily. 


POST /call-back/server/
callback-URI: http://www.myhomeaddress.com/myuri/CORRELATIONID_1234

<message>
<peer_identity>http:///some_uri_representing_my_identity</peer_identity>

You'll notice a trend. URIs and hyperlinks are a core part of REST.
That's why Mark and others have a terminological mismatch when they say:
"Web Services are not just about hypermedia." In Mark (and my) view of
the world a purchase order is hypermedia because it has references to
customer resources, supplier resources, product resources, etc.
-- 
Come discuss XML and REST web services at:
  Open Source Conference: July 22-26, 2002, conferences.oreillynet.com
  Extreme Markup: Aug 4-9, 2002,  www.extrememarkup.com/extreme/
Received on Tuesday, 16 July 2002 16:11:56 GMT

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