W3C home > Mailing lists > Public > public-html@w3.org > February 2009

Re: Placing elements in the HTML namespace

From: Ian Hickson <ian@hixie.ch>
Date: Thu, 12 Feb 2009 01:59:11 +0000 (UTC)
To: James Graham <jgraham@opera.com>
Cc: HTML WG <public-html@w3.org>
Message-ID: <Pine.LNX.4.62.0902120158100.28232@hixie.dreamhostps.com>

On Fri, 16 Jan 2009, James Graham wrote:
> Ian Hickson wrote:
> > On Thu, 15 Jan 2009, James Graham wrote:
> > > The requirement that UAs place all HTML elements in the HTML namespace
> > > does not make sense for all classes of UA. For html5lib I plan to make it
> > > optional whether HTML elements are assigned to the HTML namespace so that
> > > people using APIs that have a significant namespace tax do not have to pay
> > > that tax in the common case.
> > 
> > This wouldn't be non-conforming, since you don't expose a (W3C) DOM. 
> 
> It's not clear to me that Section 8.2.5.1 agrees with this. Insofar as
> building non-DOM trees is supported by the specification at all, requirements
> like "the UA must first create an element for the token in the HTML namespace"
> (where HTML namespace is linked to the corresponding URI) do not seem to be
> DOM-specific.
> 
> > The requirement is a black-box requirement that is only testable if the UA
> > also supports Selectors (with namespaces), XPath, W3C DOM scripting, or such
> > like.
> 
> It seems to me that what I want is, from the point of view of other resources
> in the browsing context of the page, a MUST level requirement that elements be
> in the HTML namespace (so scripts, CSS, etc always work with elements in the
> HTML namespace regardless of UA). For cases like screen scraping, however,
> application-level code is being written against the tree and portability
> between different implementations of the tree API is a less significant
> concern than ease-of-use in the API. Therefore from the point of view of such
> application-level code the parser should be allowed to put HTML elements in no
> namespace (maybe with a SHOULD requirement that it does not).

I've tried addressing this, in r2797.

I tried adding an example to explain it in more detail, but I couldn't 
really work out how you would distinguish between HTML and MathML nodes in 
html5lib if you don't really have namespaces. Could you elaborate?

-- 
Ian Hickson               U+1047E                )\._.,--....,'``.    fL
http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
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Received on Thursday, 12 February 2009 01:59:50 UTC

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