- From: Mark Baker <distobj@acm.org>
- Date: Mon, 30 Aug 2004 10:50:19 -0400
- To: www-tag@w3.org
Hi all, I believe there to be a rather large Web-architectural flaw with the recent WS-Addressing submission[1] that I wanted to raise with the TAG. The spec itself covers a lot of ground, but I'm primarily interested in section 2[2], "Endpoint References". As you might expect from the use of the word "reference" (and even the title of the spec, "addressing"), there is considerable overlap with URIs. More specifically, what the WS-Addressing spec appears to be doing is actually *discouraging* the use of URIs for identification, and instead replacing them with an XML document (the EPR). Consider the following example[3] of such a document; <wsa:EndpointReference xmlns:wsa="..." xmlns:fabrikam="..."> <wsa:Address>http://www.fabrikam123.example/acct</wsa:Address> <wsa:ReferenceProperties> <fabrikam:CustomerKey>123456789</fabrikam:CustomerKey> </wsa:ReferenceProperties> <wsa:ReferenceParameters> <fabrikam:ShoppingCart>ABCDEFG</fabrikam:ShoppingCart> </wsa:ReferenceParameters> </wsa:EndpointReference> In that example, the URI "http://www.fabrikam123.example/acct" is used to identify a "gateway" of sorts, beyond which one is left requiring the use of the CustomerKey value for the actual identification of the customer account resource. Can any of the WS-Addressing submitters explain why the customer account isn't just identified by a URI such as this one? http://www.fabrikam123.example/acct/123456789 (I'm ignoring the reference parameter there for the moment since it's role is slightly different than the property, and should not, arguably, be part of the URI) If the issue here is that Web services needs to license a client to peek into an identifier (which seems to be the case, otherwise why would you standardize it?), I would recommend that they define a new URI scheme, say, "epr". This would at least be consistent with the webarch good practice item[4] which states; "Agents making use of URIs SHOULD NOT attempt to infer properties of the referenced resource except as specified by relevant specifications." But on the other hand, I don't see why this licensing is required, and therefore why a relatively opaque http URI wouldn't suffice. Thanks. [1] http://www.w3.org/Submission/2004/SUBM-ws-addressing-20040810/ [2] http://www.w3.org/Submission/2004/SUBM-ws-addressing-20040810/#_Toc77464317 [3] http://www.w3.org/Submission/2004/SUBM-ws-addressing-20040810/#_Toc77464320 [4] http://www.w3.org/TR/webarch/#pr-uri-opacity Mark. -- Mark Baker. Ottawa, Ontario, CANADA. http://www.markbaker.ca
Received on Monday, 30 August 2004 14:49:07 UTC