xml-dev - Re: SAX Future

[<david@megginson.com>]

Michael Kay writes:

 > - I'd add two more features: (a) an option to ask the parser not to
 > break character data except at element boundaries.

This is much easier to handle with a SAX filter that implements both
Parser and DocumentHandler and buffers the character data.  As a
matter of fact, I'd like to formalise the idea of a SAX filter in SAX
1.0.1 (I think I'd like the first two digits to correspond to the XML
version).

In fact, a string of filters (Chain of Responsibility in
Design-Pattern-speak) can give users an awful lot of control for very
little work.  Other interesting filters would automatically include
XML documents embedded with XLink into the parent document's event
stream, resolve namespaces (John Cowan has already done this),
normalise whitespace using xml:space, selectively filter out elements,
etc.  All of this can be done above the parser/driver level, so
there's no need to complicate SAX by including it in the core spec
itself (except for including a canonical Filter interface).

 > (b) a "parser manager" to provide control of which parser is
 > used. (This of course is a bit of software not just an interface! -
 > I'll offer the parser manager in SAXON as a starter; it should be
 > extended to allow a pile of parser filters to be configured)

Agreed, though the design may have to vary dramatically from language
to language.

 > I think we can manage compatibility as follows:
 > - We design 2.0 so that an application that conforms to SAX 1.0 also
 > conforms to SAX 2.0
 > - A standard wrapper round a SAX 1.0 parser should enable it to conform to
 > SAX 2.0, providing null/default implementations of the new features where
 > necessary. (E.g. the response to the question "are you a validating parser?"
 > is "maybe").

Yes, but how do we accomplish this?  Do we invent a new package name
for SAX 1.0.1 to avoid collision?


All the best,


David

-- 
David Megginson                 david@megginson.com
           http://www.megginson.com/

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