SAX 2.0 extension proposals.
msabin at cromwellmedia.co.uk
Wed Feb 2 13:55:04 GMT 2000
Toby Speight wrote,
> [snip: XMLImplementation and filters]
> It would be nice if Miles gave some thought to this issue.
> Perhaps it's an insoluble problem; perhaps filters need some
> additional feature types (or additional queries on those
> features) to indicate how the the upstream parser's behaviour
> is modified.
Actually, I don't think there's a problem here. The
org.xml.sax.helpers.XMLFilter itself isn't intended to be
used directly ... it's meant to be extended by SAX applications
(David: I think it should be marked as abstract). That being
so, there's no reason for it to have a corresponding concrete
Now, if you extend it,
public class MyFilter
// override methods as required
you could do something like this,
public class MyFilterImpl
private XMLReaderImplementation itsBaseImpl;
// Locate a base implementation to wrap
// MyFilter's around.
getImplementation(... features wanted ...);
public boolean supportsBoolean(String name, boolean state)
// Just pass through here, but we could adapt
return itsBaseImpl.supportsFeature(name, state);
public XMLReader createReader()
return new MyFilter(itsBaseImpl.createReader());
and add a provider file pointing to MyFilterImpl.
I'm not sure that this solves _all_ the problems, but it looks
like it covers quite a few cases.
Miles Sabin Cromwell Media
Internet Systems Architect 5/6 Glenthorne Mews
+44 (0)20 8817 4030 London, W6 0LJ, England
msabin at cromwellmedia.com http://www.cromwellmedia.com/
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