Re: Few questions about REST

On Tue, Sep 16, 2003 at 06:32:45AM -0400, Sergey Beryozkin wrote:
> Hello Mark,
> 
> > > So when you said that "doc-lit SOAP is RESTful" what did you mean by
> that ?
> >
> > Did I say that? <snip/>
> Yes you did :-). And it's now in www-archive :-)

If you're referring to;

"To me "doc-style SOAP" is "RESTful SOAP"."
  -- http://lists.w3.org/Archives/Public/www-archive/2003Sep/0020.html

What I meant is that if you want to be doing document style SOAP,
you should really be using REST.  I didn't mean to suggest that
all so-called document-style uses of SOAP are RESTful.

> > I think I may have said that the RESTful use of SOAP looks like doc/lit,
> > but where there's no method in the body.  i.e. where the document is just
> > state.
> And I'm just trying to see how RESTful a doc-lit SOAP *can* be.

Understood.

> It seems you do agree that a doc-lit SOAP can meet a resource identification
> constraint.

*Can*, yes.

> Doc-lit SOAP can also meet a uniform interface constraint, that is all
> identified resources support the same uniform interface, at least POST and
> GET.

*Can*, yes.

> The only question to me is it a uniform interface constraint which is not
> met completely when POST is used instead of GET (the same as it can be used
> instead of PUT and DELETE), I think it's a uniform interface one, and this
> is what I meant when saying that doc-lit SOAP doesn't meet the constraint
> strictly. Or is it some other, perhaps a derived constraint, which is not
> met in such a case ?

Understood.

Strictly, the REST uniform interface constraint only requires that the
interface semantics be uniform.  It doesn't require that you don't do
the equivalent of GET via POST.  Moreover, I don't believe any of REST's
other constraints disallow it.

I've run into issues like this before with REST, and when I've asked
Roy about it, his answer was basically that it was one of those "Don't
shoot yourself in the foot" things; that it was too obvious not to
include as a constraint.

> Doc-Lit SOAP can also meet other REST constraints.

Yes, I think it *could* meet all of them.

But so could rpc/encoded.

I don't believe it's particularly useful to say what *could* be, at
least without detailing what's involved in making it so.  I would say
that it's more useful to relate what people do today with doc/lit, to
REST.

> So, can we say that a doc-lit SOAP is "mostly" RESTful, taking into account
> that it can meet all constraints ?

No.  "doc/lit", by itself, is insufficiently constraining.  Thousands
of people already know what it means, and if you say that it is mostly
RESTful, they'll think that they're already close enough to REST.

Ethernet and TCP "can meet all constraints" of REST, but we wouldn't
say those are RESTful.  "Mostly RESTful" means that the system *DOES*
intern the important constraints of REST; it doesn't mean that it *CAN*.

Mark.
-- 
Mark Baker.   Ottawa, Ontario, CANADA.        http://www.markbaker.ca

Received on Tuesday, 16 September 2003 08:58:33 UTC