> Does SAX support the notion of a low-level/full-control interface
> with high-level/app-safe layers over it? Is this what filters do?
> Does anyone have a pointer to a conceptual overview of the SAX
> object hierarchy?
SAX provides no explicit support for doing so, but what you suggest is
implicit in the design: SAX was intended to provide very low-level
parse information that middle layers (such as a DOM implementation or
some other object model) can present to application writers in a more
palatable form. In the end, I bent a little to the wishes of the
masses and included a few friendly helper classes, but for the most
part, SAX is still more IP than HTTP.
There are two major advantages to keeping SAX relatively stupid:
1. Parser writers do not need to implement too much, so they're more
likely to support SAX (as has happened almost universally among
Java parser writers).
2. Application writers aren't stuck with a single, high-level object
model.
All the best,
David
--
David Megginson david@megginson.com
http://www.megginson.com/