ANN: SAX 2.0 extension proposals.

David Megginson david at
Mon Jan 31 23:05:16 GMT 2000

Miles Sabin <msabin at> writes:

> There are, however, a few areas where I think a little bit more 
> needs to be done. I've put my code where my mouth is, and 
> written up and implemented a set of proposals for additions to 
> SAX 2.0beta. These proposals mostly cover things that have 
> already been discussed on this list,

Thank you again for the feedback.

> * A means of querying an XMLReader implementations features 
>   without first having to instantiate an XMLReader.

That's not too hard: it would take only a few static methods.  There
are a couple of issues, though:

1. For a filter (which may be more common than a root reader), the
   features available depend on the features supported by the parent
   -- in other words, you cannot know what features are supported
   *until* the reader is instantiated.

2. You cannot enforce static methods with an interface, so they would
   have to be a matter of convention (like a no-argument constructor).

The second is minor, but the first may be much more serious.

> * A plug'n'play XMLReader factory which supports multiple 
>   parsers and transparent adaptation of SAX 1 parsers.

Does this belong in the SAX core, or should it be a higher-level app?
I ask because I'm trying to keep the core sax2.jar as small as
possible, since it will usually be only a minor part of an app.

> * An extended ParserAdapter which exposes a SAX 1 parsers
>   support for validation.

I don't know if this belongs in SAX1 per se, since there's no way to
know in the general case.  People writing adapters for specific SAX1
parsers (where validation is known) can extend ParserAdapter to add
that information.

> * A couple of utility interfaces which bundle up the standard 
>   SAX 2.0 feature and property identifiers.

Two issues here:

1. I'm trying to limit bloat.

2. I expect that the list of core feature and property identifiers
   will be able to grow *without* a new SAX release, so the class
   would become outdated.

All the best,


David Megginson                 david at

xml-dev: A list for W3C XML Developers. To post, mailto:xml-dev at
Archived as: or CD-ROM/ISBN 981-02-3594-1
Please note: New list subscriptions and unsubscriptions
are  now ***CLOSED*** in preparation for list transfer to OASIS.

More information about the Xml-dev mailing list