# Bryan Schumaker (10/24/2010)

import xml.dom.minidom as xml

def attributes(node):
	attrs = dict()
	for i in range(node.attributes.length):
		item = node.attributes.item(i)
		attrs[item.name] = item.nodeValue
	return attrs

def children(doc):
	list = []
	for node in doc.childNodes:
		if node.nodeType == node.TEXT_NODE:
			if node.data.strip() == "":
				continue
		list += [node]
	return list

def child(doc):
	list = children(doc)
	if len(list) > 0:
		return list[0]
	return None

def check_type(value):
	if value.__class__ == unicode:
		return value.encode("utf-8")
	return str(value)

def add_child(doc, node, name, attrs = {}):
	child = doc.createElement(name)
	for attr in attrs:
		value = check_type(attrs[attr])
		child.setAttribute(attr, value)
	node.appendChild(child)
	return child

def add_text(doc, node, value):
	value = check_type(value)
	try:
		child = doc.createTextNode( value )
		node.appendChild(child)
		return value
	except Exception, e:
		print e
		print value, value.__class__

def get_elements(doc, tag):
	return doc.getElementsByTagName(tag)

def find_attribute(doc, tag, attr, value):
	for node in get_elements(doc, tag):
		if attributes(node)[attr] == value:
			return node
	return None

def find_preferred_attribute(doc, tag, attr, values):
	for value in values:
		attr = find_attribute(doc, tag, attr, value)
		if attr:
			return attr
	None

def new():
	return xml.Document()

def parse(xml_file):
	return xml.parse(xml_file)