- From: Len Bullard <cbullard@hiwaay.net>
- Date: Fri, 14 Mar 1997 13:51:01 -0600
- To: Terry Allen <tallen@sonic.net>
- CC: w3c-sgml-wg@w3.org
Terry Allen wrote: > >len wrote > > | object encapsulation, virtual interfaces, etc. are used, > | you can't and that is exactly why some will prefer to do > | this. Inheriting the interface, not the implementation, > | and hiding the implementation is key to distributing > | objects without giving away code. I guess what I am > > So far as I understand what you're saying, such an arrangement > would rely on the user already possessing some sofware that > encapsulates the semantics of the XML. Is that right? If so, > that software already has the information about what tags are > EMPTY. Depending on the level to which they hardwire the app, yes. Would you rather send an encapsulated object down the wire, an application --, (what an instance plus processing specification, plus any embedded thingies, plus PIs which hide the DTD under smokin' syntax are), or just a data file of hierarchies of value-pairs? > | saying is, some people think the way to maintain > | proprietary code is to encapsulate and deliver only > | exposed information. I think we shall see a lot > | of applications where XML is just initialization > | data and the stylesheets are irrelevant. This is the key. It is the key to what Eve is suggesting about PIs, about the question Tim passes from the conference about "selling a million units", "competitive advantage", semantics vs data, etc. etc. etc. Push aside the syntax arguments for awhile. Forget URLs. Forget stylesheets. Why would one want to use XML and StylesheetX if all they have to do is deliver an object to the user and the object is automatically usable? It is complete, it is ready for action, it's interface is already contractually obligated. Why? If I want to add an object to an Active-X system, right now, I just have to keep up with COM. As long as the IUnknown and queryInterface pointer magic is done right, it will work. Every time. If apply containment and aggregation correctly, I even get a pretty efficient system. If I keep in-process, out-of-process, and remote process interfaces (stubs, etc.) straight, this all even works across a network transparently except for speed. Why bother with XML, HTML, SGML, or DSSSL? Keeping up with a complicated packaging scheme, stylesheets, collections, catalogs, and the other nine yards looks pretty daunting to someone who only has to submit to COM/OLE to get what they want? Right? This isn't just arbitrariness on my part. These are questions being asked very seriously in some quarters off this list, and they must be answered. I can cite the SGML legacy, I can cite the lifecycle advantages (even where seriously compromised by well-formed approaches), but to make the case for a complete XML System in a world in which the proliferation of objects is fast and accelerating, we have to answer with something that is an irrefutable advantage. I can cite one or two, but I am interested in what the list thinks. I'm not looking to stoke the fires of paranoia, but I think there is a business case and it can't be made unless the technical details are understood just a little, and the technical tradeoffs are understood a lot. Furthermore, unless one accepts and embraces the competitive position the adopter accrues, it isn't a very strong case. With SGML/XML, the adopter can lay out a company that only knows how to do ONE DTD like filleted fish: one slice/newDTD at a time. But to do it, they have to dump the stylesheets and catalogs for most applications. Ask yourselves: when does it make good sense to have a stylesheet? len
Received on Friday, 14 March 1997 15:02:32 UTC