- From: Williams, Stuart <skw@hplb.hpl.hp.com>
- Date: Thu, 7 Feb 2002 16:56:28 -0000
- To: "'Mark Baker'" <distobj@acm.org>
- Cc: xml-dist-app@w3.org
Hi Mark, > -----Original Message----- > From: Mark Baker [mailto:distobj@acm.org] > Sent: 07 February 2002 15:24 > To: skw@hplb.hpl.hp.com > Cc: xml-dist-app@w3.org > Subject: Re: SOAP & REST > > > Hi Stuart, > > > > The difference is that in the former form, a user doesn't know whether > > ^^^^person, browser or program? > > All of the above. The URI is opaque. In the absence of other > information (i.e. before invoking GET), given only the URI, > nobody knows what it does. > > > > the operation being performed is multiplication or division. > > > > Hmmm... if I were using it to calculate my taxes that would seem like a bad > > thing to me. > > But you wouldn't use just any URI that you found on a napkin to do > that job. You'd use one from some entity you trusted, that when you > invoked GET on it, described to your satisfaction that this service > was a multiplier. Machines can work exactly the same way, though > obviously they'd need a machine processable assertion of the fact that > the service was a multiplier, returned on the GET. Feels like you just contradicted your original premise: <quote> The difference is that in the former form, a user doesn't know whether the operation being performed is multiplication or division. </quote> > > > In the latter form, the client is required to specify the desired > > > operation. > > > > I find this a little perplexing... on one level these are just large > > 'opague' strings. > > In the former URI, the string "multiply" is opaque to the client. In the > latter URI, it is not (see below), modulo the hidden form field kludge I > mentioned, where the server specifies it as a sort of "callback method" - > but the *server* specifies it, not the client. > > > You seem to be suggesting that in one case a "client" needs to "know" what > > arithmetic operation is "being performed" and in the other case it doesn't. > > No, not at all. Obviously, in both cases you need to know that > multiplication is occuring. It's *how* this is known that is > accomplished differently in hypertext and RPC. > > > What I don't understand here is how it can be argued that the sequence of > > characters 'm', 'u', 'l', 't', 'i', 'p','l' and 'e' has any more or less > > significance to the client depending on whether it is preceded by a '/' and > > followed by a '?' than when it is preceded by the character sequence > > '/','?','o','p','e','r','a','t','i','o','n', '=' and '"' and followed by '"' > > and '+'. > > See the Opacity axiom, specifically this sentence; > > "Query strings are clearly not opaque to the client." I'll think on that a while... > MB > -- > Mark Baker, Chief Science Officer, Planetfred, Inc. > Ottawa, Ontario, CANADA. mbaker@planetfred.com > http://www.markbaker.ca http://www.planetfred.com > Cheers, Stuart
Received on Thursday, 7 February 2002 11:56:44 UTC