[XML-SIG] WSDL library ?
Wed, 13 Feb 2002 17:05:17 -0700
OK. Quick answers because, like Paul, I don't have a lot of time to repeat
what I've written before in this and other forums, as well as in articles.
> > Pretty scary when I'd be more comfortable pointing people to a hack like
> > XML-RPC than I would be pointing people to SOAP.
> What's wrong with SOAP? I like it because:
> - Supports more than just sender-receiver; e.g., intermediates.
So can HTTP and SMTP, using extension headers. BEEP doesn't even need
extensions, I think.
> - SOAP with Attachments
I thought you were listing reasons for liking SOAP. I'm unable to interpret
this as such.
> - Ability to send XML
Anything can send XML. And SOAP/RPC is very lexically brittle for sending XML
has serious problems sending XML. For instance, if the embedded XML has an
XML decl, you have to escape things.
And anyway, why can't anything else send XML?
> - Richer data types
This is not an absolute statement. A CORBA person would tell you that given
structs, ANYs, object-by-value, etc., CORBA is every bit as rich in data types
Can you give a concrete example of a task that SOAP's data typs made more
possible than if you'd used other RPC mechanisms?
> - href/id handles pointer aliasing
Only if you're delivering the entire object being pointed to anyway. I hardly
see what this buys you over CORBA OBV.
> - href allows (transparent!) refs to network data
And why can't you send hrefs using any other mechanism?
> - extensible architecture (header elements)
HTTP and SMTP are also extensible. SOAP does have the advantage that
extensions can have hierarchical structure. This is one of the few true
advantages I've been able to admit for SOAP. But guess what? BEEP has the
> - reasonable size to implement
Having looked really closely at ZSI, SOAP.py, SOAPy, and our own coupel of
attempts to implement, I am astounded at this claim.
> > Good riddance.
> Why? What do you not like about it?
* Most importantly, it has nothing whatsoever to contribute to RPC except for
hierarchically extensible headers
* SOAP interoperability is a myth, as I can painfully attest
* It conflates transport and payload details
* SOAP data types consist of hack after hack, with the biggest hack being the
multi-reference values you seem to like so much
* It is wicked inefficient (5-6x the network traffic, several times the
latency and about 100 times the marshalling/unmarshalling expense when
compared to OmniORB/Python, in my low-fidelity observation)
Funny thing is that Clay Shirky makes a completely different set of points from my own, and still manages to roast WS quite handily
Uche Ogbuji Principal Consultant
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Fourthought, Inc. http://Fourthought.com
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