- From: Mark Baker <distobj@acm.org>
- Date: Thu, 7 Feb 2002 10:23:54 -0500 (EST)
- To: skw@hplb.hpl.hp.com (Williams Stuart)
- Cc: xml-dist-app@w3.org
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. > > 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." MB -- Mark Baker, Chief Science Officer, Planetfred, Inc. Ottawa, Ontario, CANADA. mbaker@planetfred.com http://www.markbaker.ca http://www.planetfred.com
Received on Thursday, 7 February 2002 10:34:42 UTC