Python code coverage for Lib/xml/dom/domreg.py

#	count	content
1	n/a	"""Registration facilities for DOM. This module should not be used
2	n/a	directly. Instead, the functions getDOMImplementation and
3	n/a	registerDOMImplementation should be imported from xml.dom."""
4	n/a
5	n/a	# This is a list of well-known implementations. Well-known names
6	n/a	# should be published by posting to xml-sig@python.org, and are
7	n/a	# subsequently recorded in this file.
8	n/a
9	n/a	well_known_implementations = {
10	n/a	'minidom':'xml.dom.minidom',
11	n/a	'4DOM': 'xml.dom.DOMImplementation',
12	n/a	}
13	n/a
14	n/a	# DOM implementations not officially registered should register
15	n/a	# themselves with their
16	n/a
17	n/a	registered = {}
18	n/a
19	n/a	def registerDOMImplementation(name, factory):
20	n/a	"""registerDOMImplementation(name, factory)
21	n/a
22	n/a	Register the factory function with the name. The factory function
23	n/a	should return an object which implements the DOMImplementation
24	n/a	interface. The factory function can either return the same object,
25	n/a	or a new one (e.g. if that implementation supports some
26	n/a	customization)."""
27	n/a
28	n/a	registered[name] = factory
29	n/a
30	n/a	def _good_enough(dom, features):
31	n/a	"_good_enough(dom, features) -> Return 1 if the dom offers the features"
32	n/a	for f,v in features:
33	n/a	if not dom.hasFeature(f,v):
34	n/a	return 0
35	n/a	return 1
36	n/a
37	n/a	def getDOMImplementation(name=None, features=()):
38	n/a	"""getDOMImplementation(name = None, features = ()) -> DOM implementation.
39	n/a
40	n/a	Return a suitable DOM implementation. The name is either
41	n/a	well-known, the module name of a DOM implementation, or None. If
42	n/a	it is not None, imports the corresponding module and returns
43	n/a	DOMImplementation object if the import succeeds.
44	n/a
45	n/a	If name is not given, consider the available implementations to
46	n/a	find one with the required feature set. If no implementation can
47	n/a	be found, raise an ImportError. The features list must be a sequence
48	n/a	of (feature, version) pairs which are passed to hasFeature."""
49	n/a
50	n/a	import os
51	n/a	creator = None
52	n/a	mod = well_known_implementations.get(name)
53	n/a	if mod:
54	n/a	mod = __import__(mod, {}, {}, ['getDOMImplementation'])
55	n/a	return mod.getDOMImplementation()
56	n/a	elif name:
57	n/a	return registered[name]()
58	n/a	elif "PYTHON_DOM" in os.environ:
59	n/a	return getDOMImplementation(name = os.environ["PYTHON_DOM"])
60	n/a
61	n/a	# User did not specify a name, try implementations in arbitrary
62	n/a	# order, returning the one that has the required features
63	n/a	if isinstance(features, str):
64	n/a	features = _parse_feature_string(features)
65	n/a	for creator in registered.values():
66	n/a	dom = creator()
67	n/a	if _good_enough(dom, features):
68	n/a	return dom
69	n/a
70	n/a	for creator in well_known_implementations.keys():
71	n/a	try:
72	n/a	dom = getDOMImplementation(name = creator)
73	n/a	except Exception: # typically ImportError, or AttributeError
74	n/a	continue
75	n/a	if _good_enough(dom, features):
76	n/a	return dom
77	n/a
78	n/a	raise ImportError("no suitable DOM implementation found")
79	n/a
80	n/a	def _parse_feature_string(s):
81	n/a	features = []
82	n/a	parts = s.split()
83	n/a	i = 0
84	n/a	length = len(parts)
85	n/a	while i < length:
86	n/a	feature = parts[i]
87	n/a	if feature[0] in "0123456789":
88	n/a	raise ValueError("bad feature name: %r" % (feature,))
89	n/a	i = i + 1
90	n/a	version = None
91	n/a	if i < length:
92	n/a	v = parts[i]
93	n/a	if v[0] in "0123456789":
94	n/a	i = i + 1
95	n/a	version = v
96	n/a	features.append((feature, version))
97	n/a	return tuple(features)