Re: SAX2: When to resolve System Ids

"Karl Waclawek" <karl@xxxxxxxxxxxx>
wrote on 03/31/2004 12:30:03 AM:

> 
> > When I raised this a couple weeks ago, it got lost (possibly
because these 
> > threads are getting fragmented between sax-devel and xml-dev)
in the 
> > discussion on the canonical location for feature documentation.
Either it 
> > was always intended that the systemId passed to 
> > DeclHandler.externalEntityDecl() be fully resolved or including
this 
> > method among those affected by resolve-dtd-uris is an error.
> 
> For now I have decided to implement it like the feature 
> documentation suggests,
> as I fail to see why externalEntityDecl() should be treated differently.
> Maybe I am overlooking something obvious.

Two words... backwards compatibility.

I believe the text in DeclHandler.externalEntityDecl()
predates this feature. It says that systemId is the 'declared' system identifier.
Xerces for instance reports the declared system identifier as it was specified
in the document to DeclHandler.externalEntityDecl(). It reports an absolute
URI for DTDHandler.notationDecl() and DTDHandler.unparsedEntityDecl().
It's what the javadoc says. I agree this doesn't make much sense, but changing
the behaviour for DeclHandler.externalEntityDecl() now has the potential
to affect users of SAX who rely on this parameter being the specified system
identifier and not the one absolutized against a base URI.

Michael Glavassevich
XML Parser Development
IBM Toronto Lab
E-mail: mrglavas@xxxxxxxxxx
E-mail: mrglavas@xxxxxxxxxx