On 08/02/06, Stephen Stagg <[EMAIL PROTECTED]> wrote: > Why do we need an HTML 5? Can't we dispose of HTML and just use > styled XML in the future? It would be one helluva way to enforce > standards, and we wouldn't have all this wrangling over exactly which > element to use. HTML in itself is not a good example of an XML > doctype because the paragraph markup does not lend itself to proper > hierarchic layout. the heading tags should be able to be subsets of > a paragraph, for example.
Well, it's a question of attaching semantic meaning to the structure of the data. XML has zero semantic meaning for elements. In XML, <hdusdlejncy wiakhjsem="blah"> has exactly the same semantic meaning as <a href="blah">. That is, no meaning at all. We need some kind of attachement mechanism for semantics. This is provided in two possible ways, either externally by the mimetype or internally by namespaces. XHTML, SVG, RSS, Atom etc. can all be summarised as sets of semantics. And by all means things closer to the heart of XML such as XLink, XInclude, XML Schemas, XLS-FO, XLST etc. too. What we really want to do when we create documents isn't usually just to provide a structure for data to present in a certain way. We want to convey some kind of meaning. The meaning can't be conveyed by CSS. It's possible we could create a semantics attachment model, but semantics on the whole aren't easily representable for computer understanding. A much easier solution is to use specific sets of semantics, which we attach by namespaces or mimetypes. All consumers can then see if they support the mimetype or namespace, and attach the semantics of that set of semantics to the underlying structure. In fact, consumers of XML that don't know the semantic set of a namespace are still able to say that the meaning is described by that namespace, even if they don't know in particular what that meaning is. These sets of semantics are of course the XML applications such as XHTML1 or XHTML5. > The focus would then shift to CSS and the different display-types > that can be defined for ANY tag. Microformats and Micro-Namespaces > could then be used to allow true semantic delivery. But really, you need a namespace to attach meaning in XML. XHTML is a known and widely implemented namespace. Why not use this namespace as base for extended semantics, instead of introducing new namespaces for it? And as for microformats, those are actually just extensions of the semantic set of this very namespace, or extensions of other sets of semantics. You can't attach semantics to XML without these tools, really. Microformats are just semantics attached to normally semantically indifferent constructs in an already existing set of semantics. > I take it this has been suggested before, so what are the arguments / > counter-arguments ?? Arguments for using plain home made XML is that you might want higher granularity and specificity of semantics than provided by preexisting XML applications. But really, to get that you essentially need to create that set of semantics and assign it to a namespace. Just naming something <footnote> or <navigation> doesn't mean it gets the semantic meaning of being a footnote or navigation. Nor does it convey any particular definition of how to handle that if no presentational or behavioral hints exists explicitly in the document, because the defaults on not-strictly-semantical aspects are also part of the semantic sets (In my view, at least. Which isn't neccesarily canon...) Counter arguments against it I think I've already mentioned. -- David "liorean" Andersson <uri:http://liorean.web-graphics.com/> ****************************************************** The discussion list for http://webstandardsgroup.org/ See http://webstandardsgroup.org/mail/guidelines.cfm for some hints on posting to the list & getting help ******************************************************
