[whatwg] several messages about XML syntax and HTML5

Mon Dec 4 03:10:08 PST 2006

Le Mon, 04 Dec 2006 09:55:32 +0200, Ian Hickson <ian at hixie.ch> a écrit:

>
> I've been having a lot of trouble following this discussion, because I
> can't work out what it is that is being asked for. There seem to be
> multiple discussions going on, and it isn't clear to me that everybody
> really knows what they are arguing for or against.

Agreed.

> I've changed the spec to allow a (meaningless) "xmlns" attribute on the
> root <html> element, for the same reasons /> is allowed on void elements
> now. I don't think it's a particularly useful thing, but I'm curious to
> see what people think. (Like anything in the spec, we might remove it in
> due course, based on real world experiences with the spec.)

IMHO, requests for allowing the xmlns attribute and other XMLiness is a  
bit over the board. I am for allowing the trailing slashes, they do no  
harm, and they help us on the server side, under strict control. Also,  
according to statistics you've provided the trailing slashes are used  
right now on 50% of web pages.

However, in the same "spirit", a middle way for those who want XMLiness in  
HTML, would be to allow the xmlns:?.* attribute, xml:base, xml:id, and  
xml:lang. Yet, define them as meaningless. Just for validation purposes,  
just for helping people who do such things on the server-side.

It should be taken into consideration that this will add a lot of  
confusion.

> There seem to be other issues being raised, though. Here's some possible
> things I think people might be asking for, based on the thread so far and
> on discussions on IRC:
>
> Possible Request A: We want a way to add proprietary markup to HTML
> documents, and have them be usable by text/html browsers.

I don't.

> Possible Request B: We want a way to add markup representing standard
> vocabularies other than HTML (e.g. MathML, SVG, DocBook, RDF) to HTML
> documents, and have them be usable by text/html browsers.

This would be interesting.

There have been proposal (AFAIK) for adding a new attribute to HTML,  
something like "ns". The value being either an URI (like XMLNS), or a  
fixed set of values: svg, mathml, etc.

Personally I wouldn't like having two attributes serving similar purposes  
(ns in HTML, xmlns in XHTML). I would also not like having the ns  
attribute provide a different set of values (compared to xmlns). Providing  
a fixed set of values is not desirable.

If you feel like adding the attribute, I recommend to reuse XMLNS in a way  
that is as close as possible to the real XMLNS.

> Possible Request C: We want XML-style draconian error handling for
> text/html.

403 Bad request :).

> Possible Request D: We want HTML-style graceful error handling for XML
> content sent.

It's already happening (somehow). Opera 9 allows reparsing XHTML web pages  
as HTML.

I'd say there shouldn't be an XML-specific "graceful error handling"  
algorithm. If there's any error handling to be ever added to XML parsers,  
that should be as close as possible to HTML itself.

> Possible Request E: We want to use XML syntactic sugar in HTML.

CDATA is useful, but as you said further down in your email: the real Web  
matters.

> Possible Request F: We want a powerful tool chain like the XML one.

Who doesn't want this?

> [...]

Overall, I see everyone is pushing his/her own "agenda". Everyone wants  
his/her own "bit" in the spec. It's like pet bugs. Nobody will be able to  
satisfy them all. You do your best to make HTML5 as good as possible. Good  
luck saying "no" to some requests :).

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