Re: Open systems / Freedom ( was RE: The Web as an Application)

On 23/09/2013 14:22, Rushforth, Peter wrote:
> I realize that XML can not be said to have a "schema", in the XML
> Schema, DTD, RelaxNG sense of the word.

As I say, you should use a different word if you want to avoid confusion:-)


> If the designers of XML had intended that the xml: namespace was a
> "no fly zone", XML Processors would reject content in that namespace
> which they do not understand.

I don't accept that argument at all: At that level you are just talking
about the parser and there are no "understood" attributes at that level
so long as it is well formed

<a zzz="sss" xml:zz=".." zz:ww="" xmlns:zz=".."/>

will be accepted by the XML (Namespace) Processor, the fact that xml:zz
is parsed without error tells you nothing more than the fact that
zz:ww="" is parsed without error. The XML Namespace is predeclared
but that is the only difference, all attributes are accepted
by a non-validating parser and may or may not be accepted by a
validating parser or higher level application depending on the rules
specified in each case.


There are many applications where using any colon-prefixed attribute is
a pain (anything related to html for example) so for those it is much
simpler to use href="..." than ???:href="...". Especially for
applications of XML on the web, having a relationship to HTML doesn't
seem that unlikely.

Applications that are already handling namespace aware XML could
probably cope with href="..." as well (as shown by xhtml or mathml or
many other xml vocabularies that include link semantics)

If you want to use a namespace prefixed version the choice between

xml:href=".."

xlink:href=".." xmlns:xmlink="..."

newns:href=".." xmlns:newns="..."

The first is a minor, almost trivial, syntactic simplification for a
namespace aware system, with a price of all sorts of backward
compatibility and political coordination issues. I can't seriously
consider that as a viable option.

The second is done, so xlink is there if you want it, presumably you
want the semantics for this to be a bit different, which leaves the
third option.


Basically this list has achieved nothing in months as we keep coming
back to this issue of using the XML namespace, which you seem to see
as a blocking issue and so there has been no discussion of what
attributes one might actually want to specify, and what they might mean.

David

Received on Monday, 23 September 2013 14:34:26 UTC