RE: [xml-dev] What Does SOAP/WS Do that A REST System Can't?

["Marc de Graauw" <marc@marcdegraauw.com>]

I've got an actual project I wasn't able to do with REST in a satisfactory
way (although I would have liked to).

I have been writing a SOAP/WSDL specification for HL7v3 messages for the
Dutch Health Authority.

Those HL7v3 messages are in XML, and derived from older (v2) non-XML
formats, so the messages themselves have a quite venerable age. As an
example, an important class of messages is query/response. An example I've
been working on is a query with (among others) a patient id, which gets a
response with all medication that has been prescribed to this patient. In
HL7v3 the queries themselves have a lot of elements. With SOAP this is not
much of a problem: both the query and response are XML messages. With REST I
have the following options:
- Use GET, and translate the query to a URI. Now I have two different
formats for query and response, and an awful long and hard-to-read URI.
- Use POST to send the XML query and fetch the XML response. This is not
very RESTful, since the patient's medication history in the response is
naturally a resource, and GET is the RESTful way to retrieve a resource. (If
I follow this solution, I would end up using POST for all or almost all
HL7v3 interactions. If I add an envelope and headers, I've almost got SOAP
over HTTP.)
- Use PUT or POST to send the query to the receiver, and have the receiver's
server PUT or POST the response to the sender's server. Same objections as
above apply.
- Rewrite HL7v3 to use simpler queries which map more naturally to REST.
Now, of course this is not something I could do on my own, and anyway, I
believe a technology should enable me to use existing vocabularies, not
force me to rewrite them to enable the technology. (If there had been no
HL7v2 or v3, I believe using REST would have been an option, and a different
design would have made using REST in a RESTful way possible.)

IMHO REST just does not map easily to request/response patterns where the
request itself is complex.

Regards,

Marc

| -----Original Message-----
| From: Bullard, Claude L (Len) [mailto:len.bullard@intergraph.com] 
| Sent: woensdag 30 maart 2005 18:36
| To: xml-dev@lists.xml.org
| Subject: [xml-dev] What Does SOAP/WS Do that A REST System Can't?
| 
| After all the threads on this, I can't remember ever seeing 
| this question answered.  Can someone point me to a list of 
| the capabilities that one gets using
| SOAP/WS* that one won't get using REST?
| 
| len
| 
| -----------------------------------------------------------------
| The xml-dev list is sponsored by XML.org 
| <http://www.xml.org>, an initiative of OASIS 
| <http://www.oasis-open.org>
| 
| The list archives are at http://lists.xml.org/archives/xml-dev/
| 
| To subscribe or unsubscribe from this list use the subscription
| manager: <http://www.oasis-open.org/mlmanage/index.php>
|