[XML-SIG] Request For Clarification on packages

[Alexandre Fayolle]

Hi everyone,

I so far have been mainly using the DOM part of PyXML, and since I
volunteered to write a SAX wrapper around sgmlop, I'm getting to know some
other parts of the library. However, everything is not as cristal clear as
I'd like, so I thought maybe I should ask here for a few
clarifications. What I'll do is make a number of statements, which I
believe are true. If some of them are either plain wrong or inaccurate,
I'd appreciate if someone knowledgeable could correct me. 

There we go:

 * the xml.parsers module contains 4 parsers (pyexpat, sgmllib, sgmlop,
xmlproc), each of which has its own API

 * xml.sax.drivers contains SAX wrappers for the 4 parsers above, plus
wrappers for some other parsers

 * xml.sax.drivers2 contains SAX 2.0 wrappers for pyxexpat and xmlproc

 * xml.sax.expatreader really belongs to xml.sax.drivers2 but is there for
backwards compatibility. One should preferably use
xml.sax.drivers2.drv_pyexpat

 * a SAX 2.0 parser should implement the interface defined in
xml.sax.xmlreader.XmlReader

 * xml.sax.handler defines the interface that should be implemented by
someone willing to use a SAX2.0 parser. A parser making callback to
methods not defined in there is not SAX 2.0 compatible.

 * xml.sax.saxlib defines the interfaces of objects manipulated by a SAX
2.0 parser.

 * xml.sax.saxutils provides basic implementations of some of the
interfaces defined in handler and saxlib

 * xml.dom.ext.reader.Sax contains a DOM generator that uses a SAX parser,
with the Reader interface

 * xml.dom.ext.reader.Sax2 contains a DOM generator that uses a SAX 2.0
parser with the Reader interface

 * xml.dom.ext.reader.Sgmlop contains a DOM generator that uses the raw
Sgmlop reader to generate either a DOM or an HTML DOM.

 * xml.dom.ext.reader.HtmlLib is a wrapper around
xml.dom.ext.reader.Sgmlop wich provides the Reader interface

 * xml.dom.ext.reader.HtmlSax is an HTML DOM generator which uses a SAX
parser as the input (is this SAX 1 or SAX 2?)

 * xml.dom.ext.reader.PyExpat is a DOM generator that uses the raw Expat
reader together with the Reader interface

 * xml.dom.ext.reader.Sax2Lib is redundant with xml.sax.handler



Alexandre Fayolle
-- 
LOGILAB, Paris (France).
http://www.logilab.com   http://www.logilab.fr  http://www.logilab.org
Narval, the first software agent available as free software (GPL).