OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.

 


Help: OASIS Mailing Lists Help | MarkMail Help

 


 

   Re: [xml-dev] XHTML 2.0 and the death of XLink and XPointer?

[ Lists Home | Date Index | Thread Index ]

Micah Dubinko wrote:

> <disclaimer>
> I'm not in the HTML WG, though I am in the XForms WG, and we try to confer
> with each other once in a while. Everything here is personal opinion only.
> </disclaimer>

<disclaimer>I'm not sure what my opinions are on XLink and HTML, but I 
disagree with a few of Micah's assertions</disclaimer>

> Quick clarification: From my reading the 'href' attribute in XHTML2 is not
> in the xhtml2 namespace, rather it is unqualified (as in XHTML 1.x, and all
> earlier SGML flavors)

Right.  In fact the HTML WG has repeatedly complained that xlink's 
attributes being qualified is a big problem.

> * There's no concept of a link that is part of a form (either GET or POST)

Well true, but there's no notion of a link that is part of a fish or a 
bicycle either.  HTML forms are highly HTML-specific constructs with 
their associated url-encoding or POST semantics.

> * There's no concept of multiple links on the same element.
> Example, an <img> ..whoops--make that <object>.. might:
>   1. cause an image link to be traversed on load
>   2. cause a longdesc link to be traversed on user request
>   3. cause a href link to be traversed on a different kind of user request

Indeed, the XLink encoding for that would require three subelements, 
each of which could have their own content and title and role and so on 
indicators.  Why is packing it all into attributes of a single element a 
better design?  I simply don't see why this is a shortcoming.

> * Complex links can't nest properly

I wasn't aware of that, can you illustrate the problem?

> * All links intrusive into the XML syntax.

What he means is that to turn something into an XLink, you need to have 
the XLink namespace declared and you need some attributes to be in that 
namespace.  The HTML WG (or at least Steven Pemberton, presumably 
speaking for them) has repeatedly said that they find it unacceptable to 
have

   <anything-at-all xlink:href="foo">...

I assume this must simply be an aesthetic issue since the above poses no 
technical problems whatsoever, and is in fact substantially easier to 
deal with than out-of-line markup that requires you know about a schema.

>   Where would XML Schema be if xsi:type was the only way to assign
> datatypes? Out-of-line markup is a necessity in many applications.

On the other hand, in-line markup, which makes the instance more 
completely self-describing, is a huge advantage in many applications. 
This was the design prejudice of XLink.

  -Tim





 

News | XML in Industry | Calendar | XML Registry
Marketplace | Resources | MyXML.org | Sponsors | Privacy Statement

Copyright 2001 XML.org. This site is hosted by OASIS