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comparison CSP2/CSP2_env/env-d9b9114564458d9d-741b3de822f2aaca6c6caa4325c4afce/lib/python3.8/xml/dom/domreg.py @ 68:5028fdace37b

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planemo upload commit 2e9511a184a1ca667c7be0c6321a36dc4e3d116d
author jpayne
date Tue, 18 Mar 2025 16:23:26 -0400
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67:0e9998148a16 68:5028fdace37b
1 """Registration facilities for DOM. This module should not be used
2 directly. Instead, the functions getDOMImplementation and
3 registerDOMImplementation should be imported from xml.dom."""
4
5 # This is a list of well-known implementations. Well-known names
6 # should be published by posting to xml-sig@python.org, and are
7 # subsequently recorded in this file.
8
9 import sys
10
11 well_known_implementations = {
12 'minidom':'xml.dom.minidom',
13 '4DOM': 'xml.dom.DOMImplementation',
14 }
15
16 # DOM implementations not officially registered should register
17 # themselves with their
18
19 registered = {}
20
21 def registerDOMImplementation(name, factory):
22 """registerDOMImplementation(name, factory)
23
24 Register the factory function with the name. The factory function
25 should return an object which implements the DOMImplementation
26 interface. The factory function can either return the same object,
27 or a new one (e.g. if that implementation supports some
28 customization)."""
29
30 registered[name] = factory
31
32 def _good_enough(dom, features):
33 "_good_enough(dom, features) -> Return 1 if the dom offers the features"
34 for f,v in features:
35 if not dom.hasFeature(f,v):
36 return 0
37 return 1
38
39 def getDOMImplementation(name=None, features=()):
40 """getDOMImplementation(name = None, features = ()) -> DOM implementation.
41
42 Return a suitable DOM implementation. The name is either
43 well-known, the module name of a DOM implementation, or None. If
44 it is not None, imports the corresponding module and returns
45 DOMImplementation object if the import succeeds.
46
47 If name is not given, consider the available implementations to
48 find one with the required feature set. If no implementation can
49 be found, raise an ImportError. The features list must be a sequence
50 of (feature, version) pairs which are passed to hasFeature."""
51
52 import os
53 creator = None
54 mod = well_known_implementations.get(name)
55 if mod:
56 mod = __import__(mod, {}, {}, ['getDOMImplementation'])
57 return mod.getDOMImplementation()
58 elif name:
59 return registered[name]()
60 elif not sys.flags.ignore_environment and "PYTHON_DOM" in os.environ:
61 return getDOMImplementation(name = os.environ["PYTHON_DOM"])
62
63 # User did not specify a name, try implementations in arbitrary
64 # order, returning the one that has the required features
65 if isinstance(features, str):
66 features = _parse_feature_string(features)
67 for creator in registered.values():
68 dom = creator()
69 if _good_enough(dom, features):
70 return dom
71
72 for creator in well_known_implementations.keys():
73 try:
74 dom = getDOMImplementation(name = creator)
75 except Exception: # typically ImportError, or AttributeError
76 continue
77 if _good_enough(dom, features):
78 return dom
79
80 raise ImportError("no suitable DOM implementation found")
81
82 def _parse_feature_string(s):
83 features = []
84 parts = s.split()
85 i = 0
86 length = len(parts)
87 while i < length:
88 feature = parts[i]
89 if feature[0] in "0123456789":
90 raise ValueError("bad feature name: %r" % (feature,))
91 i = i + 1
92 version = None
93 if i < length:
94 v = parts[i]
95 if v[0] in "0123456789":
96 i = i + 1
97 version = v
98 features.append((feature, version))
99 return tuple(features)