More Gems From the Mines

from xml.dom import Node

from xml.ns import XMLNS


def _splitname(name):

    '''Split a name, returning prefix, localname, qualifiedname.

    '''

    i = name.find(u':')

    if i == -1: return u'', name, name

    return name[:i], name[i + 1:], name


def _initattrs(n, type):

    '''Set the initial node attributes.

    '''

    n.attributes = {}

    n.childNodes = []

    n.nodeType = type

    n.parentNode = None

    n.namespaceURI = u''


class SimpleContentNode:

    '''A CDATA, TEXT, or COMMENT node.

    '''

    def __init__(self, type, text):

	_initattrs(self, type)

	self.data = text


class SimplePINode:

    '''A PI node.

    '''

    def __init__(self, name, value):

	_initattrs(self, Node.PROCESSING_INSTRUCTION_NODE)

	self.name, self.value, self.nodeValue = name, value, value


class SimpleAttributeNode:

    '''An element attribute node.

    '''

    def __init__(self, name, value):

	_initattrs(self, Node.ATTRIBUTE_NODE)

	self.value, self.nodeValue = value, value

	self.prefix, self.localName, self.nodeName = _splitname(name)


class SimpleElementNode:

    '''An element.  Might have children, text, and attributes.

    '''

    def __init__(self, name, nsdict = None, newline = 1):

	if nsdict:

	    self.nsdict = nsdict.copy()

	else:

	    self.nsdict = {}

	_initattrs(self, Node.ELEMENT_NODE)

	self.prefix, self.localName, self.nodeName = _splitname(name)

	self.namespaceURI = self.nsdict.get(self.prefix, None)

	for k,v in self.nsdict.items():

	    self.addNSAttr(k, v)

	if newline: self.addText(u'\n')


    def nslookup(self, key):

	n = self

	while n:

	    if n.nsdict.has_key(key): return n.nsdict[key]

	    n = n.parentNode

	raise KeyError, u'namespace prefix %s not found' % key


    def addAttr(self, name, value):

	n = SimpleAttributeNode(name, value)

	n.parentNode = self

	if not n.prefix:

	    n.namespaceURI = None

	else:

	    n.namespaceURI = self.nslookup(n.prefix)

	self.attributes[name] = n

	return self


    def addNSAttr(self, prefix, value):

	if prefix:

	    n = SimpleAttributeNode(u'xmlns:' + prefix, value)

	else:

	    n = SimpleAttributeNode(u'xmlns', value)

        #XMLNS.BASE is the special namespace W3C

        #circularly uses for namespace declaration attributes themselves

	n.parentNode, n.namespaceURI = self, XMLNS.BASE

	self.attributes[u'xmlns:'] = n

	self.nsdict[prefix] = value

	return self


    def addDefaultNSAttr(self, value):

	return self.addNSAttr(u'', value)


    def addChild(self, n):

	n.parentNode = self

	if n.namespaceURI == None: n.namespaceURI = self.namespaceURI

	self.childNodes.append(n)

	return self


    def addText(self, text):

	n = SimpleContentNode(Node.TEXT_NODE, text)

	return self.addChild(n)


    def addCDATA(self, text):

	n = SimpleContentNode(Node.CDATA_SECTION_NODE, text)

	return self.addChild(n)


    def addComment(self, text):

	n = SimpleContentNode(Node.COMMENT_NODE, text)

	return self.addChild(n)


    def addPI(self, name, value):

	n = SimplePINode(name, value)

	return self.addChild(n)

	return self


    def addElement(self, name, nsdict = None, newline = 1):

	n = SimpleElementNode(name, nsdict, newline)

	self.addChild(n)

	return n


if __name__ == '__main__':

    e = SimpleElementNode('z', {'': 'uri:example.com', 'q':'q-namespace'})


    n = e.addElement('zchild')

    n.addNSAttr('d', 'd-uri')

    n.addAttr('foo', 'foo-value')

    n.addText('some text for d\n')

    n.addElement('d:k2').addText('innermost txt\n')


    e.addElement('q:e-child-2').addComment('This is a comment')

    e.addText('\n')

    e.addElement('ll:foo', { 'll': 'example.org'})

    e.addAttr('eattr', '''eat at joe's''')


    from xml.dom.ext import Canonicalize

    print Canonicalize(e, comments=1)

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