Sam Ruby writes;

The very notion of a link has become practically inexpressible and virtually unthinkable in the vernacular of SOA.

That’s an awesome soundbite, but I don’t think that’s the (whole) problem because SOA/WS does have links, they’re called EPRs.

But what SOA doesn’t offer, is a uniform interface for the targets of those links, and a uniform interface is what gives the links most of their value as each one contains sufficient information to initiate a subsequent action (e.g. GET).

There’s a unique symbiotic relationship between links and the uniform interface that makes the whole greater than the sum of the parts; individually they’re useful, but together they changed the world.


no comment until now

  1. Semantics. WSDL has always had xsd:anyURI. I’m sure that you would agree that neither quite have the semantics of “link”.

    It is worth noting that hypertext links rarely occur in HTTP headers. HTML+HTTP are the expoxy of the web.

  2. WSDL doesn’t count because it’s not part of the messages. But no, I *do* think EPRs are links. Poorly designed links mind you (no scheme, crappy syntax), but links nonetheless.

    I think that if SOAP were to have been defined with a “turn this EPR into data” method, that we’d be seeing a lot more EPRs.

    And yah, I though about including HTML in there too, as a carrier of links, but three’s a crowd (at least for an epoxy analogy 8-)

  3. Mark Mc Keown

    For me links/URIs are part of the uniform interface, as you say the whole is greater than the sum.

    People are trying to use EPRs as links, in WSRF for example. Of course they often don’t realise that is what they are doing.

    I have found the Location and Referrer HTTP Headers useful for passing around URIs.

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