Re: [xml-dev] Re: determining ID-ness in XML

[Rob Lugt <roblugt@elcel.com>]

Richard Tobin wrote:
>
> It's certainly not valid *now*; but we could choose either to make it
> valid or not.  That is, we could either say that there is an implicit
> declaration for xml:id on every element [*], or say that for validity a
> declaration is required.
>
> Having an implicit declaration would not break any existing document,
> since xml:id is currently reserved.

But having an implicit declaration would create two classes of Validity.
Existing (non xmlid-conformant parsers) would declare the document invalid
whereas updated applications would declare it valid.  The idea of an
implicit declaration is also inconsistent with other recommendations such as
XML Namespaces, which explicitly does not change validation rules and
therefore requires "xmlns" to be declared.

Much to Tim Bray's dismay, I think that a variation of James Clark's idea
using PIs may be best:- Use an attribute name attribute, but make it a
pseudo-attribute inside a processing instruction.

e.g.  <?xml-typeinfo idnames="abc:id, ID, id"?>

Regards
~Rob