Re: Schemas and entities (was "And the DTD says, "I'm NOT dead yet!!")

[David Carlisle <davidc@nag.co.uk>]

   Further bulletin from the front: this doesn't mean you can't use a
   validating parser as the first stage of an XML Schema-aware processor,
   or that you will of necessity be beset by error messages from it if
   you do and only use the DOCTYPE statement to define internal general
   entities: The XML Infoset draft spec. [1], on which the XML Schema
   draft spec. [2] depends in this regard, makes clear that a
   well-formed-but-invalid XML document has a perfectly good infoset.
   (XML 1.0 DTD-based) validation itself, i.e. XML 1.0 DTD-based
   processing beyond that which is required of non-validating processors) 
   of documents with no external subset affects nothing which XML
   Schema-aware processing is sensitive to.


I think maybe it's Friday here as well, but I lost the thread of that
paragrah, so maybe the point below is irrelevant, but anyway...

If the XML uses entity references then there has to be a <!DOCTYPE else
it's not well formed, no?  So to use a validating parser as the first
stage of schema processing you must have a full DTD referenced in the
DOCTYPE surely.

In other words, although a "well-formed-but-invalid XML document has a
perfectly good infoset" you can't necessarily get at that infoset using
a validating parser (as such a beast has the right to die on you).

David

_____________________________________________________________________
This message has been checked for all known viruses by Star Internet delivered
through the MessageLabs Virus Control Centre. For further information visit
http://www.star.net.uk/stats.asp