1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
|
from importlib import import_module
from django.core.exceptions import ImproperlyConfigured
from django.utils.module_loading import module_has_submodule
from django.utils._os import upath
MODELS_MODULE_NAME = 'models'
class AppConfig(object):
"""
Class representing a Django application and its configuration.
"""
def __init__(self, app_name, app_module):
# Full Python path to the application eg. 'django.contrib.admin'.
self.name = app_name
# Root module for the application eg. <module 'django.contrib.admin'
# from 'django/contrib/admin/__init__.pyc'>.
self.module = app_module
# The following attributes could be defined at the class level in a
# subclass, hence the test-and-set pattern.
# Last component of the Python path to the application eg. 'admin'.
# This value must be unique across a Django project.
if not hasattr(self, 'label'):
self.label = app_name.rpartition(".")[2]
# Human-readable name for the application eg. "Admin".
if not hasattr(self, 'verbose_name'):
self.verbose_name = self.label.title()
# Filesystem path to the application directory eg.
# u'/usr/lib/python2.7/dist-packages/django/contrib/admin'. May be
# None if the application isn't a bona fide package eg. if it's an
# egg. Otherwise it's a unicode on Python 2 and a str on Python 3.
if not hasattr(self, 'path'):
try:
self.path = upath(app_module.__path__[0])
except AttributeError:
self.path = None
# Module containing models eg. <module 'django.contrib.admin.models'
# from 'django/contrib/admin/models.pyc'>. Set by import_models().
# None if the application doesn't have a models module.
self.models_module = None
# Mapping of lower case model names to model classes. Initally set to
# None to prevent accidental access before import_models() runs.
self.models = None
def __repr__(self):
return '<%s: %s>' % (self.__class__.__name__, self.label)
@classmethod
def create(cls, entry):
"""
Factory that creates an app config from an entry in INSTALLED_APPS.
"""
try:
# If import_module succeeds, entry is a path to an app module.
# Otherwise, entry is a path to an app config class or an error.
module = import_module(entry)
except ImportError:
# Avoid django.utils.module_loading.import_by_path because it
# masks errors -- it reraises ImportError as ImproperlyConfigured.
mod_path, _, cls_name = entry.rpartition('.')
# Raise the original exception when entry cannot be a path to an
# app config class.
if not mod_path:
raise
mod = import_module(mod_path)
try:
cls = getattr(mod, cls_name)
except AttributeError:
# Emulate the error that "from <mod_path> import <cls_name>"
# would raise when <mod_path> exists but not <cls_name>, with
# more context (Python just says "cannot import name ...").
raise ImportError(
"cannot import name '%s' from '%s'" % (cls_name, mod_path))
# Check for obvious errors. (This check prevents duck typing, but
# it could be removed if it became a problem in practice.)
if not issubclass(cls, AppConfig):
raise ImproperlyConfigured(
"'%s' isn't a subclass of AppConfig." % entry)
# Obtain app name here rather than in AppClass.__init__ to keep
# all error checking for entries in INSTALLED_APPS in one place.
try:
app_name = cls.name
except AttributeError:
raise ImproperlyConfigured(
"'%s' must supply a name attribute." % entry)
# Ensure app_name points to a valid module.
app_module = import_module(app_name)
# Entry is a path to an app config class.
return cls(app_name, app_module)
else:
# Entry is a path to an app module.
return cls(entry, module)
def get_model(self, model_name):
"""
Returns the model with the given case-insensitive model_name.
Raises LookupError if no model exists with this name.
"""
if self.models is None:
raise LookupError(
"App '%s' doesn't have any models." % self.label)
try:
return self.models[model_name.lower()]
except KeyError:
raise LookupError(
"App '%s' doesn't have a '%s' model." % (self.label, model_name))
def get_models(self, include_auto_created=False,
include_deferred=False, include_swapped=False):
"""
Returns an iterable of models.
By default, the following models aren't included:
- auto-created models for many-to-many relations without
an explicit intermediate table,
- models created to satisfy deferred attribute queries,
- models that have been swapped out.
Set the corresponding keyword argument to True to include such models.
Keyword arguments aren't documented; they're a private API.
"""
for model in self.models.values():
if model._deferred and not include_deferred:
continue
if model._meta.auto_created and not include_auto_created:
continue
if model._meta.swapped and not include_swapped:
continue
yield model
def import_models(self, all_models):
# Dictionary of models for this app, primarily maintained in the
# 'all_models' attribute of the Apps this AppConfig is attached to.
# Injected as a parameter because it gets populated when models are
# imported, which might happen before populate() imports models.
self.models = all_models
if module_has_submodule(self.module, MODELS_MODULE_NAME):
models_module_name = '%s.%s' % (self.name, MODELS_MODULE_NAME)
self.models_module = import_module(models_module_name)
def ready(self):
"""
Override this method in subclasses to run code when Django starts.
"""
|
