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Re: ISSUE-41/ACTION-97 decentralized-extensibility

From: Jonas Sicking <jonas@sicking.cc>
Date: Thu, 1 Oct 2009 01:02:26 -0700
Message-ID: <63df84f0910010102nefa386dnc63a194d66ae7e5f@mail.gmail.com>
To: Julian Reschke <julian.reschke@gmx.de>
Cc: Adrian Bateman <adrianba@microsoft.com>, HTML WG <public-html@w3.org>, Tony Ross <tross@microsoft.com>, Sam Ruby <rubys@intertwingly.net>
On Wed, Sep 30, 2009 at 11:26 PM, Julian Reschke <julian.reschke@gmx.de> wrote:
> Jonas Sicking wrote:
>>
>> ...
>> I'm not actually a big fan of this proposal. Experience with
>> namespaces in XML has showed (at least to me) that namespaces are too
>> complex for authors to understand. The most recent example of this was
>> the discussion on RDFa+HTML where it was clear that even the experts
>> that developed RDFa thought of nodes as receiving their meaning from
>> their nodeName rather than from their localName+namespaceURI.
>> ...
>
> Pointer?

This is one example:

http://lists.w3.org/Archives/Public/public-html/2009Sep/0923.html

But really, the whole thread is filled with missunderstandings about
how namespaced nodes in the DOM work.

>> Additionally, the SVG working group is hard at work trying to get away
>> from exposing their users (SVG authors) to the SVG namespace. I'm
>> assuming that this is based on feedback from authors disliking the SVG
>> namespace.
>>
>> Even the RDFa working group has moved away from the namespacing
>> mechanism that XML Namespaces is using. RDFa is based on CURIEs, which
>> is a compacted single string, rather than the string-tuple that XML
>> Namespaces force upon users.
>> ...
>
> Not sure what you're comparing here. As far as I can tell, there is no
> proposal here to use prefixes (a la qname or curie) in content.

Are you asking just in relation to the second of my paragraphs above?
I don't understand the question if it's in relation to the first one
as well.

Assuming it applies to the second:

One of the problems with namespacing a'la XML Namespaces is that an
objects identifing name isn't a single string, it's a tuple. Everyone
has to lug around two separate values, localName and namespaceURI.
(Many times implementations have to lug around three values,
localName, namespaceURI, and prefix).

RDF has not chosen to use this. Instead it concatenates the expanded
prefix together with the localName-esq value in order to form a single
string. Each part of an RDF triplet, subject, predicate and object, is
identified by a single string (though in the case of object there's
additionally a datatype). The triplet does not consist of 3 string
tuples.

So while RDFa keeps one (what I perceive) complexity of XML
Namespaces, the use of prefixes, it has done away with another
complexity, namely the use of string tuples as identifiers.

However the proposal from microsoft still uses tuples of strings to
identify element and attribute names.

/ Jonas
Received on Thursday, 1 October 2009 08:03:22 UTC

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