XMLClassBuilder.py

Revision 644, 11.9 kB (checked in by sholloway, 5 years ago)
Made skin:trylist only catch element factory and import errors

Line
1	#!/usr/bin/env python
2	##~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
3	##~ License
4	##~
5	##- The RuneBlade Foundation library is intended to ease some
6	##- aspects of writing intricate Jabber, XML, and User Interface (wxPython, etc.)
7	##- applications, while providing the flexibility to modularly change the
8	##- architecture. Enjoy.
9	##~
10	##~ Copyright (C) 2002 TechGame Networks, LLC.
11	##~
12	##~ This library is free software; you can redistribute it and/or
13	##~ modify it under the terms of the BSD style License as found in the
14	##~ LICENSE file included with this distribution.
15	##~
16	##~ TechGame Networks, LLC can be reached at:
17	##~ 3578 E. Hartsel Drive #211
18	##~ Colorado Springs, Colorado, USA, 80920
19	##~
20	##~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
21
22	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
23	#~ Imports
24	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
25
26	from __future__ import generators
27	import XMLBuilder
28	import keyword
29
30	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
31	#~ Definitions
32	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
33
34	ElementFactoryError = XMLBuilder.ElementFactoryError
35
36	class ElementFactory(object):
37	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
38	#~ Definitions
39	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
40
41	class Static(object):
42	def __init__(self, result):
43	self.result = result
44	def __call__(self, args, *kw):
45	return self.result
46
47	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
48
49	class Raise(object):
50	def __init__(self, exception=ElementFactoryError, message=''):
51	self.exception = exception
52	self.message = message
53
54	def __call__(self, args, *kw):
55	raise self.exception, self.message
56
57	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
58
59	class InheritFromNextFactory(Exception):
60	def __call__(self, args, *kw):
61	raise self.__class__, (args, kw)
62
63	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
64
65	class BaseImport(object):
66	retryimport = True
67
68	def __init__(self, PyPathRoot=''):
69	self.PyPathRoot = PyPathRoot
70	self._CachedElementFactories = {}
71
72	def IsEnabled(self):
73	try:
74	return self._enabled
75	except AttributeError:
76	try:
77	__import__(self.PyPathRoot, globals(), {})
78	except ImportError:
79	self._enabled = False
80	else:
81	self._enabled = True
82	return self._enabled
83
84	def _DoImport(self, PyPath, Name):
85	if not self.IsEnabled():
86	raise ImportError, 'Import element finder %r is disabled because root %r cannot be imported' % (self, self.PyPathRoot)
87
88	if self.PyPathRoot and PyPath:
89	PyPath = '.'.join((self.PyPathRoot, PyPath))
90	elif not PyPath:
91	PyPath = self.PyPathRoot
92	module = __import__(PyPath, globals(), {}, Name)
93
94	try:
95	return getattr(module, Name)
96	except AttributeError:
97	if self.retryimport:
98	module = reload(module)
99	try: return getattr(module, Name)
100	except AttributeError: pass
101	raise ElementFactoryError, 'Could not find "%s" in module %r' % (Name, module)
102
103	def __call__(self, owner, parent, node, attributes, namespacemap):
104	result = self._CachedElementFactories.get(node, None)
105	if not result:
106	ns, name = node
107	if keyword.iskeyword(name): name = name + '_'
108	result = self._DoImport('', name)
109
110	## The following works for another scheme
111	##result = self.DoImport(*node)
112
113	self._CachedElementFactories[node] = result
114	return result
115
116	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
117
118	class StaticImport(BaseImport):
119	def __init__(self, PyPath, Name, args, *kw):
120	ElementFactory.BaseImport.__init__(self, PyPath)
121	self.name = Name
122	self.result = None
123
124	def __call__(self, args, *kw):
125	if not self.result:
126	self.result = self._DoImport('', self.name)
127	return self.result
128
129	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
130
131	class NodeImport(BaseImport):
132	def __call__(self, owner, parent, node, attributes, namespacemap):
133	result = self._CachedElementFactories.get(node, None)
134	if not result:
135	ns, name = node
136	if keyword.iskeyword(name): name = name + '_'
137	result = self._DoImport(name, name)
138
139	## The following works for another scheme
140	##result = self.DoImport(*node)
141
142	self._CachedElementFactories[node] = result
143	return result
144
145	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
146
147	class NamespaceImport(BaseImport):
148	def __call__(self, owner, parent, node, attributes, namespacemap):
149	result = self._CachedElementFactories.get(node, None)
150	if not result:
151	ns, name = node
152	if keyword.iskeyword(name): name = name + '_'
153	result = self._DoImport('%s.%s' % (ns, name), name)
154
155	## The following works for another scheme
156	##result = self.DoImport(*node)
157
158	self._CachedElementFactories[node] = result
159	return result
160
161	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
162
163	class TryList(object):
164	def __init__(self, trylist, ignoreExceptions=[ElementFactoryError, ImportError]):#, AttributeError, KeyError]):
165	self._trylist = trylist
166	self._ignoreExceptions = tuple(ignoreExceptions)
167
168	def __call__(self, owner, parent, node, attributes, namespacemap):
169	for each in self._trylist:
170	try:
171	return each(owner, parent, node, attributes, namespacemap)
172	except self._ignoreExceptions:
173	pass
174
175	raise ElementFactoryError('No suitable element factory for node %r' % (node,))
176
177	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
178
179	class CachedTryList(TryList):
180	def __init__(self, args, *kw):
181	ElementFactory.TryList.__init__(self, args, *kw)
182	self._CachedElementFactories = {}
183
184	def __call__(self, owner, parent, node, attributes, namespacemap):
185	result = self._CachedElementFactories.get(node, None)
186	if result:
187	return result
188	for each in self._trylist:
189	try:
190	result = each(owner, parent, node, attributes, namespacemap)
191	self._CachedElementFactories[node] = result
192	return result
193	except self._ignoreExceptions, e:
194	pass
195
196	raise ElementFactoryError('No suitable element factory for node %r' % (node,))
197
198	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
199
200	class ElementFactorySet(dict):
201	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
202	#~ Constants / Variables / Etc.
203	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
204
205	NextFactorySet = None
206	_PushCount = 0
207
208	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
209	#~ Public Methods
210	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
211
212	def PushFactorySet(self, FactorySet):
213	if FactorySet is not self:
214	self.NextFactorySet = FactorySet
215	self._PushCount = 1
216	else:
217	self._PushCount += 1
218	return self
219
220	def PopFactorySet(self):
221	self._PushCount -= 1
222	if self._PushCount <= 0:
223	result = self.NextFactorySet
224	self.NextFactorySet = None
225	return result
226	else:
227	return self
228
229	def copy(self):
230	return self.__class__(dict.copy(self))
231
232	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
233	#~ Protected Methods
234	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
235
236	def _GetElementFactoryIndices(self, node):
237	idx = node
238	while idx:
239	yield idx
240	idx = idx[:-1]
241	yield None
242
243	def _GetElementFactory(self, owner, parent, node, attributes, namespacemap):
244	try:
245	for idx in self._GetElementFactoryIndices(node):
246	FactoryFactory = self.get(idx)
247	if FactoryFactory is not None:
248	result = FactoryFactory(owner, parent, node, attributes, namespacemap)
249	if result:
250	return result
251	except ElementFactory.InheritFromNextFactory, (args, kw):
252	if self.NextFactorySet:
253	return self.NextFactorySet._GetElementFactory(args, *kw)
254
255	raise ElementFactoryError("Could not find a class to build for node %r" % (node,))
256
257	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
258
259	class XMLClassBuilderBaseMixin(object):
260	"""Mixin that forms the python import indirectly from a dictionary lookup of the namespace,
261	and then combines the result with the node name."""
262
263	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
264	#~ Constants / Variables / Etc.
265	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
266
267	ElementFactories = ElementFactorySet()
268
269	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
270	#~ Public Methods
271	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
272
273	def AddElementFactory(self, idx, Factory):
274	self.ElementFactorySet[idx] = Factory
275
276	def RemoveElementFactory(self, idx):
277	try:
278	del self.ElementFactorySet[idx]
279	return True
280	except KeyError:
281	return False
282
283	def AddElementFactories(self, Factories):
284	"""Registeres a new mapping between xmlns and python import strings."""
285	# Did they send us a real change?
286	if Factories:
287	# And now update with what they gave us
288	self.ElementFactorySet.update(Factories)
289
290	def RemoveElementFactories(self, Factories):
291	# Did they send us a real change?
292	return map(self.RemoveElementFactory, Frctories or ())
293
294	def PushElementFactorySet(self, FactorySet):
295	result = self.ElementFactories
296	self.ElementFactories = FactorySet.PushFactorySet(result)
297	return result
298
299	def PopElementFactorySet(self):
300	result = self.ElementFactories
301	self.ElementFactories = result.PopFactorySet()
302	return result
303
304	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
305	#~ Protected Methods
306	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
307
308	def _GetModifableElementFactoryDict(self):
309	# Are we working on the class dictionary?
310	if self.ElementFactories is self.__class__.ElementFactories:
311	# If so, lets get an instance copy
312	self.ElementFactories = self.ElementFactories.copy()
313	return self.ElementFactories
314	ElementFactorySet = property(_GetModifableElementFactoryDict)
315
316	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
317
318	class XMLClassBuilderMixin(XMLClassBuilderBaseMixin, XMLBuilder.XMLBuilderMixin):
319	def _GetElementFactory(self, owner, parent, node, attributes, namespacemap):
320	if self._elements:
321	result = self._elements[-1]._xmlChildFactory(owner, parent, node, attributes, namespacemap)
322	if result: return result
323	return self.ElementFactorySet._GetElementFactory(owner, parent, node, attributes, namespacemap)
324
325	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
326
327	class XMLClassBuilderObjectMixin(XMLClassBuilderBaseMixin):
328	def _xmlChildFactory(self, owner, parent, node, attributes, namespacemap):
329	return self.ElementFactorySet._GetElementFactory(owner, parent, node, attributes, namespacemap)
330
331	#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
332
333	class XMLClassBuilder(XMLClassBuilderMixin, XMLBuilder.XMLExpatBuilderMixin):
334	pass
335

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root/trunk/RBFoundation/RBFoundation/XMLClassBuilder.py

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