[XML-SIG] Whitespace handling in XMLWriter

[Radestock, Guenter]

I am using xml.sax.writer to produce nicely indentex XML output from Python.
The xmlwriter is pretty good at indentation and formatting, but for some
tags, I would like to have whitespace preserved.  I did not see a way
to tell this via the doctype info.  Right now I am using the following:


class OutputWriter:
    def __init__(self, fo=sys.stdout):
        self.fo = fo
        self.containers = []
        self.docinfo = xml.sax.writer.XMLDoctypeInfo()
        
        saxout = self.saxout = xml.sax.writer.PrettyPrinter(
            self.fo, dtdinfo=self.docinfo, endtagindentation=-2)
        # put a print here to see how (slow) output is generated.
        # there should not be a visible delay between the message
        # printed and the log output of the http server.
        #print '### starting xml output'
        saxout.startDocument()

    def pcdata_tag(self, name, s):
        s = '%s' % s
        self.saxout.startElement(name)
        self.saxout.characters(s, 0, len(s))
        self.saxout.endElement(name)

    def start_tag(self, name):
        if not name in self.containers:
            # needed to make pretty printing work (the pretty
            # printer needs to know where whitespace is allowed
            # in the output)
            self.containers.append(name)
            self.docinfo.add_element_container(name)
        self.saxout.startElement(name, {})

    def end_tag(self, name):
        self.saxout.endElement(name)

    def comment(self, text):
        text = ' ' + text + ' '
        self.saxout.comment(text, 0, len(text))

    def close(self):
        self.saxout.endDocument()
        self.fo.flush()

This works the way I want only for short content (there is no whitespace
inserted before and after).  Passing longer strings, possibly with
whitespace, to pcdata_tag will reformat, changing the internal and
external whitespace contained in my text.

Is there a way to do this with the current xmlwriter or is this
missing right now?

- Guenter