[XML-SIG] DOM walker examples

[Kevin Russell]

I notice the XML howto still has a blank space for examples
of DOM walking.  I've finally wrapped my head around
CVS (by the way, is it a good idea for the howto to talk about
stuff that's only available through CVS and not from the ordinary
web-site?) and played around with it.  A couple of my toy
programs might be appropriate howto-examples, so here
they are.

-- Kevin Russell

--------------
"""killnote.py
A DOM-walker example:  remove all "note" elements from a document
"""

from xml.dom import utils, walker
from sys import argv

class NoteKiller (walker.Walker):
    def startElement(self,node):
        if node.nodeName == 'note':
            node.parentNode.removeChild(node)

if __name__ == '__main__':
    f = utils.FileReader()
    doc = f.readFile(argv[1])
    NoteKiller().walk(doc)
    print doc.toxml()


---------------
"""renumber.py
A DOM-walker example: give each element a unique ID attribute
"""

from xml.dom import utils, walker
from sys import argv

class NumberingWalker (walker.Walker):
    counters = {}
    def startElement(self,node):
        try:
            self.counters[node.nodeName] = self.counters[node.nodeName]
+ 1
        except KeyError:
            self.counters[node.nodeName] = 1
        node.setAttribute('id', '%s%s' % (node.nodeName,
self.counters[node.nodeName]))

if __name__ == '__main__':
    f = utils.FileReader()
    doc = f.readFile(argv[1])
    NumberingWalker().walk(doc)
    print doc.toxml()