Show More
@@ -1,315 +1,328 b'' | |||||
1 | #!/usr/bin/env python |
|
1 | #!/usr/bin/env python | |
2 | # encoding: utf-8 |
|
2 | # encoding: utf-8 | |
3 | """ |
|
3 | """ | |
4 | A base class for objects that are configurable. |
|
4 | A base class for objects that are configurable. | |
5 |
|
5 | |||
6 | Authors: |
|
6 | Authors: | |
7 |
|
7 | |||
8 | * Brian Granger |
|
8 | * Brian Granger | |
9 | * Fernando Perez |
|
9 | * Fernando Perez | |
10 | * Min RK |
|
10 | * Min RK | |
11 | """ |
|
11 | """ | |
12 |
|
12 | |||
13 | #----------------------------------------------------------------------------- |
|
13 | #----------------------------------------------------------------------------- | |
14 | # Copyright (C) 2008-2011 The IPython Development Team |
|
14 | # Copyright (C) 2008-2011 The IPython Development Team | |
15 | # |
|
15 | # | |
16 | # Distributed under the terms of the BSD License. The full license is in |
|
16 | # Distributed under the terms of the BSD License. The full license is in | |
17 | # the file COPYING, distributed as part of this software. |
|
17 | # the file COPYING, distributed as part of this software. | |
18 | #----------------------------------------------------------------------------- |
|
18 | #----------------------------------------------------------------------------- | |
19 |
|
19 | |||
20 | #----------------------------------------------------------------------------- |
|
20 | #----------------------------------------------------------------------------- | |
21 | # Imports |
|
21 | # Imports | |
22 | #----------------------------------------------------------------------------- |
|
22 | #----------------------------------------------------------------------------- | |
23 |
|
23 | |||
24 | import datetime |
|
24 | import datetime | |
25 | from copy import deepcopy |
|
25 | from copy import deepcopy | |
26 |
|
26 | |||
27 | from loader import Config |
|
27 | from loader import Config | |
28 | from IPython.utils.traitlets import HasTraits, Instance |
|
28 | from IPython.utils.traitlets import HasTraits, Instance | |
29 | from IPython.utils.text import indent, wrap_paragraphs |
|
29 | from IPython.utils.text import indent, wrap_paragraphs | |
30 |
|
30 | |||
31 |
|
31 | |||
32 | #----------------------------------------------------------------------------- |
|
32 | #----------------------------------------------------------------------------- | |
33 | # Helper classes for Configurables |
|
33 | # Helper classes for Configurables | |
34 | #----------------------------------------------------------------------------- |
|
34 | #----------------------------------------------------------------------------- | |
35 |
|
35 | |||
36 |
|
36 | |||
37 | class ConfigurableError(Exception): |
|
37 | class ConfigurableError(Exception): | |
38 | pass |
|
38 | pass | |
39 |
|
39 | |||
40 |
|
40 | |||
41 | class MultipleInstanceError(ConfigurableError): |
|
41 | class MultipleInstanceError(ConfigurableError): | |
42 | pass |
|
42 | pass | |
43 |
|
43 | |||
44 | #----------------------------------------------------------------------------- |
|
44 | #----------------------------------------------------------------------------- | |
45 | # Configurable implementation |
|
45 | # Configurable implementation | |
46 | #----------------------------------------------------------------------------- |
|
46 | #----------------------------------------------------------------------------- | |
47 |
|
47 | |||
48 | class Configurable(HasTraits): |
|
48 | class Configurable(HasTraits): | |
49 |
|
49 | |||
50 | config = Instance(Config,(),{}) |
|
50 | config = Instance(Config,(),{}) | |
51 | created = None |
|
51 | created = None | |
52 |
|
52 | |||
53 | def __init__(self, **kwargs): |
|
53 | def __init__(self, **kwargs): | |
54 | """Create a configurable given a config config. |
|
54 | """Create a configurable given a config config. | |
55 |
|
55 | |||
56 | Parameters |
|
56 | Parameters | |
57 | ---------- |
|
57 | ---------- | |
58 | config : Config |
|
58 | config : Config | |
59 | If this is empty, default values are used. If config is a |
|
59 | If this is empty, default values are used. If config is a | |
60 | :class:`Config` instance, it will be used to configure the |
|
60 | :class:`Config` instance, it will be used to configure the | |
61 | instance. |
|
61 | instance. | |
62 |
|
62 | |||
63 | Notes |
|
63 | Notes | |
64 | ----- |
|
64 | ----- | |
65 | Subclasses of Configurable must call the :meth:`__init__` method of |
|
65 | Subclasses of Configurable must call the :meth:`__init__` method of | |
66 | :class:`Configurable` *before* doing anything else and using |
|
66 | :class:`Configurable` *before* doing anything else and using | |
67 | :func:`super`:: |
|
67 | :func:`super`:: | |
68 |
|
68 | |||
69 | class MyConfigurable(Configurable): |
|
69 | class MyConfigurable(Configurable): | |
70 | def __init__(self, config=None): |
|
70 | def __init__(self, config=None): | |
71 | super(MyConfigurable, self).__init__(config) |
|
71 | super(MyConfigurable, self).__init__(config) | |
72 | # Then any other code you need to finish initialization. |
|
72 | # Then any other code you need to finish initialization. | |
73 |
|
73 | |||
74 | This ensures that instances will be configured properly. |
|
74 | This ensures that instances will be configured properly. | |
75 | """ |
|
75 | """ | |
76 | config = kwargs.pop('config', None) |
|
76 | config = kwargs.pop('config', None) | |
77 | if config is not None: |
|
77 | if config is not None: | |
78 | # We used to deepcopy, but for now we are trying to just save |
|
78 | # We used to deepcopy, but for now we are trying to just save | |
79 | # by reference. This *could* have side effects as all components |
|
79 | # by reference. This *could* have side effects as all components | |
80 | # will share config. In fact, I did find such a side effect in |
|
80 | # will share config. In fact, I did find such a side effect in | |
81 | # _config_changed below. If a config attribute value was a mutable type |
|
81 | # _config_changed below. If a config attribute value was a mutable type | |
82 | # all instances of a component were getting the same copy, effectively |
|
82 | # all instances of a component were getting the same copy, effectively | |
83 | # making that a class attribute. |
|
83 | # making that a class attribute. | |
84 | # self.config = deepcopy(config) |
|
84 | # self.config = deepcopy(config) | |
85 | self.config = config |
|
85 | self.config = config | |
86 | # This should go second so individual keyword arguments override |
|
86 | # This should go second so individual keyword arguments override | |
87 | # the values in config. |
|
87 | # the values in config. | |
88 | super(Configurable, self).__init__(**kwargs) |
|
88 | super(Configurable, self).__init__(**kwargs) | |
89 | self.created = datetime.datetime.now() |
|
89 | self.created = datetime.datetime.now() | |
90 |
|
90 | |||
91 | #------------------------------------------------------------------------- |
|
91 | #------------------------------------------------------------------------- | |
92 | # Static trait notifiations |
|
92 | # Static trait notifiations | |
93 | #------------------------------------------------------------------------- |
|
93 | #------------------------------------------------------------------------- | |
94 |
|
94 | |||
95 | def _config_changed(self, name, old, new): |
|
95 | def _config_changed(self, name, old, new): | |
96 | """Update all the class traits having ``config=True`` as metadata. |
|
96 | """Update all the class traits having ``config=True`` as metadata. | |
97 |
|
97 | |||
98 | For any class trait with a ``config`` metadata attribute that is |
|
98 | For any class trait with a ``config`` metadata attribute that is | |
99 | ``True``, we update the trait with the value of the corresponding |
|
99 | ``True``, we update the trait with the value of the corresponding | |
100 | config entry. |
|
100 | config entry. | |
101 | """ |
|
101 | """ | |
102 | # Get all traits with a config metadata entry that is True |
|
102 | # Get all traits with a config metadata entry that is True | |
103 | traits = self.traits(config=True) |
|
103 | traits = self.traits(config=True) | |
104 |
|
104 | |||
105 | # We auto-load config section for this class as well as any parent |
|
105 | # We auto-load config section for this class as well as any parent | |
106 | # classes that are Configurable subclasses. This starts with Configurable |
|
106 | # classes that are Configurable subclasses. This starts with Configurable | |
107 | # and works down the mro loading the config for each section. |
|
107 | # and works down the mro loading the config for each section. | |
108 | section_names = [cls.__name__ for cls in \ |
|
108 | section_names = [cls.__name__ for cls in \ | |
109 | reversed(self.__class__.__mro__) if |
|
109 | reversed(self.__class__.__mro__) if | |
110 | issubclass(cls, Configurable) and issubclass(self.__class__, cls)] |
|
110 | issubclass(cls, Configurable) and issubclass(self.__class__, cls)] | |
111 |
|
111 | |||
112 | for sname in section_names: |
|
112 | for sname in section_names: | |
113 | # Don't do a blind getattr as that would cause the config to |
|
113 | # Don't do a blind getattr as that would cause the config to | |
114 | # dynamically create the section with name self.__class__.__name__. |
|
114 | # dynamically create the section with name self.__class__.__name__. | |
115 | if new._has_section(sname): |
|
115 | if new._has_section(sname): | |
116 | my_config = new[sname] |
|
116 | my_config = new[sname] | |
117 | for k, v in traits.iteritems(): |
|
117 | for k, v in traits.iteritems(): | |
118 | # Don't allow traitlets with config=True to start with |
|
118 | # Don't allow traitlets with config=True to start with | |
119 | # uppercase. Otherwise, they are confused with Config |
|
119 | # uppercase. Otherwise, they are confused with Config | |
120 | # subsections. But, developers shouldn't have uppercase |
|
120 | # subsections. But, developers shouldn't have uppercase | |
121 | # attributes anyways! (PEP 6) |
|
121 | # attributes anyways! (PEP 6) | |
122 | if k[0].upper()==k[0] and not k.startswith('_'): |
|
122 | if k[0].upper()==k[0] and not k.startswith('_'): | |
123 | raise ConfigurableError('Configurable traitlets with ' |
|
123 | raise ConfigurableError('Configurable traitlets with ' | |
124 | 'config=True must start with a lowercase so they are ' |
|
124 | 'config=True must start with a lowercase so they are ' | |
125 | 'not confused with Config subsections: %s.%s' % \ |
|
125 | 'not confused with Config subsections: %s.%s' % \ | |
126 | (self.__class__.__name__, k)) |
|
126 | (self.__class__.__name__, k)) | |
127 | try: |
|
127 | try: | |
128 | # Here we grab the value from the config |
|
128 | # Here we grab the value from the config | |
129 | # If k has the naming convention of a config |
|
129 | # If k has the naming convention of a config | |
130 | # section, it will be auto created. |
|
130 | # section, it will be auto created. | |
131 | config_value = my_config[k] |
|
131 | config_value = my_config[k] | |
132 | except KeyError: |
|
132 | except KeyError: | |
133 | pass |
|
133 | pass | |
134 | else: |
|
134 | else: | |
135 | # print "Setting %s.%s from %s.%s=%r" % \ |
|
135 | # print "Setting %s.%s from %s.%s=%r" % \ | |
136 | # (self.__class__.__name__,k,sname,k,config_value) |
|
136 | # (self.__class__.__name__,k,sname,k,config_value) | |
137 | # We have to do a deepcopy here if we don't deepcopy the entire |
|
137 | # We have to do a deepcopy here if we don't deepcopy the entire | |
138 | # config object. If we don't, a mutable config_value will be |
|
138 | # config object. If we don't, a mutable config_value will be | |
139 | # shared by all instances, effectively making it a class attribute. |
|
139 | # shared by all instances, effectively making it a class attribute. | |
140 | setattr(self, k, deepcopy(config_value)) |
|
140 | setattr(self, k, deepcopy(config_value)) | |
141 |
|
141 | |||
142 | @classmethod |
|
142 | @classmethod | |
143 | def class_get_help(cls): |
|
143 | def class_get_help(cls): | |
144 | """Get the help string for this class in ReST format.""" |
|
144 | """Get the help string for this class in ReST format.""" | |
145 | cls_traits = cls.class_traits(config=True) |
|
145 | cls_traits = cls.class_traits(config=True) | |
146 | final_help = [] |
|
146 | final_help = [] | |
147 | final_help.append(u'%s options' % cls.__name__) |
|
147 | final_help.append(u'%s options' % cls.__name__) | |
148 | final_help.append(len(final_help[0])*u'-') |
|
148 | final_help.append(len(final_help[0])*u'-') | |
149 | for k,v in cls.class_traits(config=True).iteritems(): |
|
149 | for k,v in cls.class_traits(config=True).iteritems(): | |
150 | help = cls.class_get_trait_help(v) |
|
150 | help = cls.class_get_trait_help(v) | |
151 | final_help.append(help) |
|
151 | final_help.append(help) | |
152 | return '\n'.join(final_help) |
|
152 | return '\n'.join(final_help) | |
153 |
|
153 | |||
154 | @classmethod |
|
154 | @classmethod | |
155 | def class_get_trait_help(cls, trait): |
|
155 | def class_get_trait_help(cls, trait): | |
156 | """Get the help string for a single trait.""" |
|
156 | """Get the help string for a single trait.""" | |
157 | lines = [] |
|
157 | lines = [] | |
158 | header = "%s.%s : %s" % (cls.__name__, trait.name, trait.__class__.__name__) |
|
158 | header = "%s.%s : %s" % (cls.__name__, trait.name, trait.__class__.__name__) | |
159 | lines.append(header) |
|
159 | lines.append(header) | |
160 | try: |
|
160 | try: | |
161 | dvr = repr(trait.get_default_value()) |
|
161 | dvr = repr(trait.get_default_value()) | |
162 | except Exception: |
|
162 | except Exception: | |
163 | dvr = None # ignore defaults we can't construct |
|
163 | dvr = None # ignore defaults we can't construct | |
164 | if dvr is not None: |
|
164 | if dvr is not None: | |
165 | if len(dvr) > 64: |
|
165 | if len(dvr) > 64: | |
166 | dvr = dvr[:61]+'...' |
|
166 | dvr = dvr[:61]+'...' | |
167 | lines.append(indent('Default: %s'%dvr, 4)) |
|
167 | lines.append(indent('Default: %s'%dvr, 4)) | |
168 | if 'Enum' in trait.__class__.__name__: |
|
168 | if 'Enum' in trait.__class__.__name__: | |
169 | # include Enum choices |
|
169 | # include Enum choices | |
170 | lines.append(indent('Choices: %r'%(trait.values,))) |
|
170 | lines.append(indent('Choices: %r'%(trait.values,))) | |
171 |
|
171 | |||
172 | help = trait.get_metadata('help') |
|
172 | help = trait.get_metadata('help') | |
173 | if help is not None: |
|
173 | if help is not None: | |
174 | help = '\n'.join(wrap_paragraphs(help, 76)) |
|
174 | help = '\n'.join(wrap_paragraphs(help, 76)) | |
175 | lines.append(indent(help, 4)) |
|
175 | lines.append(indent(help, 4)) | |
176 | return '\n'.join(lines) |
|
176 | return '\n'.join(lines) | |
177 |
|
177 | |||
178 | @classmethod |
|
178 | @classmethod | |
179 | def class_print_help(cls): |
|
179 | def class_print_help(cls): | |
180 | """Get the help string for a single trait and print it.""" |
|
180 | """Get the help string for a single trait and print it.""" | |
181 | print cls.class_get_help() |
|
181 | print cls.class_get_help() | |
182 |
|
182 | |||
183 | @classmethod |
|
183 | @classmethod | |
184 | def class_config_section(cls): |
|
184 | def class_config_section(cls): | |
185 | """Get the config class config section""" |
|
185 | """Get the config class config section""" | |
186 | def c(s): |
|
186 | def c(s): | |
187 | """return a commented, wrapped block.""" |
|
187 | """return a commented, wrapped block.""" | |
188 | s = '\n\n'.join(wrap_paragraphs(s, 78)) |
|
188 | s = '\n\n'.join(wrap_paragraphs(s, 78)) | |
189 |
|
189 | |||
190 | return '# ' + s.replace('\n', '\n# ') |
|
190 | return '# ' + s.replace('\n', '\n# ') | |
191 |
|
191 | |||
192 | # section header |
|
192 | # section header | |
193 | breaker = '#' + '-'*78 |
|
193 | breaker = '#' + '-'*78 | |
194 | s = "# %s configuration"%cls.__name__ |
|
194 | s = "# %s configuration"%cls.__name__ | |
195 | lines = [breaker, s, breaker, ''] |
|
195 | lines = [breaker, s, breaker, ''] | |
196 | # get the description trait |
|
196 | # get the description trait | |
197 | desc = cls.class_traits().get('description') |
|
197 | desc = cls.class_traits().get('description') | |
198 | if desc: |
|
198 | if desc: | |
199 | desc = desc.default_value |
|
199 | desc = desc.default_value | |
200 | else: |
|
200 | else: | |
201 | # no description trait, use __doc__ |
|
201 | # no description trait, use __doc__ | |
202 | desc = getattr(cls, '__doc__', '') |
|
202 | desc = getattr(cls, '__doc__', '') | |
203 | if desc: |
|
203 | if desc: | |
204 | lines.append(c(desc)) |
|
204 | lines.append(c(desc)) | |
205 | lines.append('') |
|
205 | lines.append('') | |
206 |
|
206 | |||
|
207 | parents = [] | |||
|
208 | for parent in cls.mro(): | |||
|
209 | # only include parents that are not base classes | |||
|
210 | # and are not the class itself | |||
|
211 | if issubclass(parent, Configurable) and \ | |||
|
212 | not parent in (Configurable, SingletonConfigurable, cls): | |||
|
213 | parents.append(parent) | |||
|
214 | ||||
|
215 | if parents: | |||
|
216 | pstr = ', '.join([ p.__name__ for p in parents ]) | |||
|
217 | lines.append(c('%s will inherit config from: %s'%(cls.__name__, pstr))) | |||
|
218 | lines.append('') | |||
|
219 | ||||
207 | for name,trait in cls.class_traits(config=True).iteritems(): |
|
220 | for name,trait in cls.class_traits(config=True).iteritems(): | |
208 | help = trait.get_metadata('help') or '' |
|
221 | help = trait.get_metadata('help') or '' | |
209 | lines.append(c(help)) |
|
222 | lines.append(c(help)) | |
210 | lines.append('# c.%s.%s = %r'%(cls.__name__, name, trait.get_default_value())) |
|
223 | lines.append('# c.%s.%s = %r'%(cls.__name__, name, trait.get_default_value())) | |
211 | lines.append('') |
|
224 | lines.append('') | |
212 | return '\n'.join(lines) |
|
225 | return '\n'.join(lines) | |
213 |
|
226 | |||
214 |
|
227 | |||
215 |
|
228 | |||
216 | class SingletonConfigurable(Configurable): |
|
229 | class SingletonConfigurable(Configurable): | |
217 | """A configurable that only allows one instance. |
|
230 | """A configurable that only allows one instance. | |
218 |
|
231 | |||
219 | This class is for classes that should only have one instance of itself |
|
232 | This class is for classes that should only have one instance of itself | |
220 | or *any* subclass. To create and retrieve such a class use the |
|
233 | or *any* subclass. To create and retrieve such a class use the | |
221 | :meth:`SingletonConfigurable.instance` method. |
|
234 | :meth:`SingletonConfigurable.instance` method. | |
222 | """ |
|
235 | """ | |
223 |
|
236 | |||
224 | _instance = None |
|
237 | _instance = None | |
225 |
|
238 | |||
226 | @classmethod |
|
239 | @classmethod | |
227 | def _walk_mro(cls): |
|
240 | def _walk_mro(cls): | |
228 | """Walk the cls.mro() for parent classes that are also singletons |
|
241 | """Walk the cls.mro() for parent classes that are also singletons | |
229 |
|
242 | |||
230 | For use in instance() |
|
243 | For use in instance() | |
231 | """ |
|
244 | """ | |
232 |
|
245 | |||
233 | for subclass in cls.mro(): |
|
246 | for subclass in cls.mro(): | |
234 | if issubclass(cls, subclass) and \ |
|
247 | if issubclass(cls, subclass) and \ | |
235 | issubclass(subclass, SingletonConfigurable) and \ |
|
248 | issubclass(subclass, SingletonConfigurable) and \ | |
236 | subclass != SingletonConfigurable: |
|
249 | subclass != SingletonConfigurable: | |
237 | yield subclass |
|
250 | yield subclass | |
238 |
|
251 | |||
239 | @classmethod |
|
252 | @classmethod | |
240 | def clear_instance(cls): |
|
253 | def clear_instance(cls): | |
241 | """unset _instance for this class and singleton parents. |
|
254 | """unset _instance for this class and singleton parents. | |
242 | """ |
|
255 | """ | |
243 | if not cls.initialized(): |
|
256 | if not cls.initialized(): | |
244 | return |
|
257 | return | |
245 | for subclass in cls._walk_mro(): |
|
258 | for subclass in cls._walk_mro(): | |
246 | if isinstance(subclass._instance, cls): |
|
259 | if isinstance(subclass._instance, cls): | |
247 | # only clear instances that are instances |
|
260 | # only clear instances that are instances | |
248 | # of the calling class |
|
261 | # of the calling class | |
249 | subclass._instance = None |
|
262 | subclass._instance = None | |
250 |
|
263 | |||
251 | @classmethod |
|
264 | @classmethod | |
252 | def instance(cls, *args, **kwargs): |
|
265 | def instance(cls, *args, **kwargs): | |
253 | """Returns a global instance of this class. |
|
266 | """Returns a global instance of this class. | |
254 |
|
267 | |||
255 | This method create a new instance if none have previously been created |
|
268 | This method create a new instance if none have previously been created | |
256 | and returns a previously created instance is one already exists. |
|
269 | and returns a previously created instance is one already exists. | |
257 |
|
270 | |||
258 | The arguments and keyword arguments passed to this method are passed |
|
271 | The arguments and keyword arguments passed to this method are passed | |
259 | on to the :meth:`__init__` method of the class upon instantiation. |
|
272 | on to the :meth:`__init__` method of the class upon instantiation. | |
260 |
|
273 | |||
261 | Examples |
|
274 | Examples | |
262 | -------- |
|
275 | -------- | |
263 |
|
276 | |||
264 | Create a singleton class using instance, and retrieve it:: |
|
277 | Create a singleton class using instance, and retrieve it:: | |
265 |
|
278 | |||
266 | >>> from IPython.config.configurable import SingletonConfigurable |
|
279 | >>> from IPython.config.configurable import SingletonConfigurable | |
267 | >>> class Foo(SingletonConfigurable): pass |
|
280 | >>> class Foo(SingletonConfigurable): pass | |
268 | >>> foo = Foo.instance() |
|
281 | >>> foo = Foo.instance() | |
269 | >>> foo == Foo.instance() |
|
282 | >>> foo == Foo.instance() | |
270 | True |
|
283 | True | |
271 |
|
284 | |||
272 | Create a subclass that is retrived using the base class instance:: |
|
285 | Create a subclass that is retrived using the base class instance:: | |
273 |
|
286 | |||
274 | >>> class Bar(SingletonConfigurable): pass |
|
287 | >>> class Bar(SingletonConfigurable): pass | |
275 | >>> class Bam(Bar): pass |
|
288 | >>> class Bam(Bar): pass | |
276 | >>> bam = Bam.instance() |
|
289 | >>> bam = Bam.instance() | |
277 | >>> bam == Bar.instance() |
|
290 | >>> bam == Bar.instance() | |
278 | True |
|
291 | True | |
279 | """ |
|
292 | """ | |
280 | # Create and save the instance |
|
293 | # Create and save the instance | |
281 | if cls._instance is None: |
|
294 | if cls._instance is None: | |
282 | inst = cls(*args, **kwargs) |
|
295 | inst = cls(*args, **kwargs) | |
283 | # Now make sure that the instance will also be returned by |
|
296 | # Now make sure that the instance will also be returned by | |
284 | # parent classes' _instance attribute. |
|
297 | # parent classes' _instance attribute. | |
285 | for subclass in cls._walk_mro(): |
|
298 | for subclass in cls._walk_mro(): | |
286 | subclass._instance = inst |
|
299 | subclass._instance = inst | |
287 |
|
300 | |||
288 | if isinstance(cls._instance, cls): |
|
301 | if isinstance(cls._instance, cls): | |
289 | return cls._instance |
|
302 | return cls._instance | |
290 | else: |
|
303 | else: | |
291 | raise MultipleInstanceError( |
|
304 | raise MultipleInstanceError( | |
292 | 'Multiple incompatible subclass instances of ' |
|
305 | 'Multiple incompatible subclass instances of ' | |
293 | '%s are being created.' % cls.__name__ |
|
306 | '%s are being created.' % cls.__name__ | |
294 | ) |
|
307 | ) | |
295 |
|
308 | |||
296 | @classmethod |
|
309 | @classmethod | |
297 | def initialized(cls): |
|
310 | def initialized(cls): | |
298 | """Has an instance been created?""" |
|
311 | """Has an instance been created?""" | |
299 | return hasattr(cls, "_instance") and cls._instance is not None |
|
312 | return hasattr(cls, "_instance") and cls._instance is not None | |
300 |
|
313 | |||
301 |
|
314 | |||
302 | class LoggingConfigurable(Configurable): |
|
315 | class LoggingConfigurable(Configurable): | |
303 | """A parent class for Configurables that log. |
|
316 | """A parent class for Configurables that log. | |
304 |
|
317 | |||
305 | Subclasses have a log trait, and the default behavior |
|
318 | Subclasses have a log trait, and the default behavior | |
306 | is to get the logger from the currently running Application |
|
319 | is to get the logger from the currently running Application | |
307 | via Application.instance().log. |
|
320 | via Application.instance().log. | |
308 | """ |
|
321 | """ | |
309 |
|
322 | |||
310 | log = Instance('logging.Logger') |
|
323 | log = Instance('logging.Logger') | |
311 | def _log_default(self): |
|
324 | def _log_default(self): | |
312 | from IPython.config.application import Application |
|
325 | from IPython.config.application import Application | |
313 | return Application.instance().log |
|
326 | return Application.instance().log | |
314 |
|
327 | |||
315 |
|
328 |
General Comments 0
You need to be logged in to leave comments.
Login now