W3C home > Mailing lists > Public > public-rdf-in-xhtml-tf@w3.org > August 2009

Re: Why bound prefixes are an anti-pattern in language design

From: Martin McEvoy <martin@weborganics.co.uk>
Date: Thu, 06 Aug 2009 22:42:59 +0100
Message-ID: <4A7B4E63.3080805@weborganics.co.uk>
To: danny.ayers@gmail.com, Ian Hickson <ian@hixie.ch>, RDFa Developers <public-rdf-in-xhtml-tf@w3.org>
Hello Ian, Danny

I wrote:
>> Here is where I have to stop you I am afraid, I am not talking about 
>> XML/Namespaces,  I am only talking about prefixing mechanisms to 
>> convey semantic meaning in a way it was intended by the author.
>>
>> for example: 
>> http://microformats.org/wiki/hatom-faq#Why_does_hAtom_use_class_names_with_prefixes 
>>
>>
>> "... since we were reusing the semantics of the IETF Atom standard, 
>> we very much wanted to reuse the vocabulary as well to minimize 
>> confusion and mean precisely the same semantics as defined in the 
>> Atom RFC 4287, and thus a few of the hAtom properties use class names 
>> that appear to have shared prefixes (entry-title, entry-content, 
>> entry-summary) in order to literally reuse those terms from the Atom 
>> RFC (title, content, summary) with the Atom-specific semantics 
>> defined therein, rather than the generic semantics, e.g. "summary" 
>> has a much more general purpose semantic that is utilized broadly by 
>> multiple microformats."
>>
>> This is more what I mean by prefixing mechanisms, these kind of 
>> mechanisms give wider, richer semantic scope than just simple generic 
>> keywords. In hAtom prefixing works and doesn't cause many issues or 
>> confusion, sure the question "is that a namespace" comes up and the 
>> answer is simply no.
>>
>> consider this example:
>>
>> <div prefix-entry="http://tools.ietf.org/html/rfc4287#"
>>       class="hentry">
>>    <h2 class="entry-title">My foo article</h2>
>>    <div class="entry-content">Hey this is foo.</div>
>> </div>
>>
> It gets a bit cryptic from here on.... What I meant was...
>
> All the above example tries to demonstrate  is creating a scope for 
> which terms can be used, there Is no namespace voodoo going on, just 
> prefixes used in a "meaningful" way, the content of prefix-entry is 
> just text that may or may not be referenced sometime later, Its a 
> reference to where the meaning of these scoped terms are being used.

RDFa is *NOT* evoking some kind of namespace routine or indirection 
behaviour , at least that is not what is intended, its  creating Scope 
within the document which uses RDF terms and values hence the 
"attributes" to emulate a certain behaviour, the re-use of xmlns for 
something "meaningful" makes no difference because in HTML5 *xmlns* has 
"no meaning" its just a token value much the same as your data- 
attribute, its just a convenient "hook" for something other than the 
browser, ":" is only text that represents a union of things much the 
same way  as the little stick thing people seem to be attached to "-"  ;)

Best wishes

-- 
Martin McEvoy
http://weborganics.co.uk/
Received on Thursday, 6 August 2009 21:43:52 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Thursday, 6 August 2009 21:43:53 GMT