xml-dev - Re: SAX Future

[John Cowan <cowan@locke.ccil.org>]

david@megginson.com wrote:

> This is much easier to handle with a SAX filter that implements both
> Parser and DocumentHandler and buffers the character data.

Which someone using my ParserFilter class can write in < 1 day.

> 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.

You betcha.  And because each filter component can specified by a Java
system property, chaining can be done at run time very neatly.

The highest level filter is specified as org.xml.sax.parser, and
each lower level is specified by <successor class name>.parser, thus:

	-D org.xml.sax.parser=com.domain.chance
	-D com.domain.chance.parser=com.domain.evers
	-D com.domain.evers.parser=com.domain.tinker
	-D com.domain.tinker.parser=com.domain.SAXDriver

sets up a chain where SAXDriver (the real parser) passes
to tinker, which passes to evers, which passes to chance, :-) which
passes to the application.

Of course all this can be set up programmatically too.

> 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).

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

I think that would be better than new class names.

-- 
John Cowan	http://www.ccil.org/~cowan		cowan@ccil.org
	You tollerday donsk?  N.  You tolkatiff scowegian?  Nn.
	You spigotty anglease?  Nnn.  You phonio saxo?  Nnnn.
		Clear all so!  'Tis a Jute.... (Finnegans Wake 16.5)

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