Re: [xml-dev] IDs considered harmful or why keys might be better thanIDs...

["Jonathan Borden" <jborden@mediaone.net>]

David Carlisle wrote:
>
>
> > Why would one need to redeclare an ID in the internal subset which is
> > already declared in the external DTD. Its already an ID right?
>
>
> Isn't that the whole point of this thread?

No, at least that is not _my_ point. When I suggest internal subset ID
declarations, it is simply to point out that we already have an implemented
but arguably imperfect syntax to declare document specific IDs.

>
> > Again, my point about using internal declarations of IDs is for
documents
> > which don't have an external DTD. If you are using an external DTD you
can
> > always declare a short DTD driver which sucks in docbook+mathml +
whatever
> > and defines the new IDs your particular application desires
>
> No. That isn't how the web works. I stick up a document and I have no
> idea what application is going to be reading it, but I know that that
> application might not read the external subset of the dtd 'cause that's
> how it is specified in the XML rec.
>

Right, but this application must also understand that it will _only_ be able
to understand identifiers that are implicit to the application, i.e. a
_docbook_ application has knowledge of a _docbook identifier_ regardless of
whether a validating parser is used. The vast majority of HTML parsers never
touch the DTD yet seem to handle <a href="#foo"> just fine.

If you are asking for a _generic_ processor that understands IDs regardless
of some magical internal knowledge of every application that exists and
every that will someday exists, then _this application must parse and
process the DTD_. ***

Jonathan

*** When I use the capitalized term "ID" I mean ID as defined in XML 1.0.