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
|
from django.core.exceptions import ImproperlyConfigured
from django.utils.importlib import import_module
# Cache of actual callables.
_standard_context_processors = None
# We need the CSRF processor no matter what the user has in their settings,
# because otherwise it is a security vulnerability, and we can't afford to leave
# this to human error or failure to read migration instructions.
_builtin_context_processors = ('django.core.context_processors.csrf',)
class ContextPopException(Exception):
"pop() has been called more times than push()"
pass
class BaseContext(object):
def __init__(self, dict_=None):
dict_ = dict_ or {}
self.dicts = [dict_]
def __repr__(self):
return repr(self.dicts)
def __iter__(self):
for d in reversed(self.dicts):
yield d
def push(self):
d = {}
self.dicts.append(d)
return d
def pop(self):
if len(self.dicts) == 1:
raise ContextPopException
return self.dicts.pop()
def __setitem__(self, key, value):
"Set a variable in the current context"
self.dicts[-1][key] = value
def __getitem__(self, key):
"Get a variable's value, starting at the current context and going upward"
for d in reversed(self.dicts):
if key in d:
return d[key]
raise KeyError(key)
def __delitem__(self, key):
"Delete a variable from the current context"
del self.dicts[-1][key]
def has_key(self, key):
for d in self.dicts:
if key in d:
return True
return False
def __contains__(self, key):
return self.has_key(key)
def get(self, key, otherwise=None):
for d in reversed(self.dicts):
if key in d:
return d[key]
return otherwise
class Context(BaseContext):
"A stack container for variable context"
def __init__(self, dict_=None, autoescape=True, current_app=None):
self.autoescape = autoescape
self.current_app = current_app
self.render_context = RenderContext()
super(Context, self).__init__(dict_)
def update(self, other_dict):
"Like dict.update(). Pushes an entire dictionary's keys and values onto the context."
if not hasattr(other_dict, '__getitem__'):
raise TypeError('other_dict must be a mapping (dictionary-like) object.')
self.dicts.append(other_dict)
return other_dict
class RenderContext(BaseContext):
"""
A stack container for storing Template state.
RenderContext simplifies the implementation of template Nodes by providing a
safe place to store state between invocations of a node's `render` method.
The RenderContext also provides scoping rules that are more sensible for
'template local' variables. The render context stack is pushed before each
template is rendered, creating a fresh scope with nothing in it. Name
resolution fails if a variable is not found at the top of the RequestContext
stack. Thus, variables are local to a specific template and don't affect the
rendering of other templates as they would if they were stored in the normal
template context.
"""
def __iter__(self):
for d in self.dicts[-1]:
yield d
def has_key(self, key):
return key in self.dicts[-1]
def get(self, key, otherwise=None):
d = self.dicts[-1]
if key in d:
return d[key]
return otherwise
# This is a function rather than module-level procedural code because we only
# want it to execute if somebody uses RequestContext.
def get_standard_processors():
from django.conf import settings
global _standard_context_processors
if _standard_context_processors is None:
processors = []
collect = []
collect.extend(_builtin_context_processors)
collect.extend(settings.TEMPLATE_CONTEXT_PROCESSORS)
for path in collect:
i = path.rfind('.')
module, attr = path[:i], path[i+1:]
try:
mod = import_module(module)
except ImportError, e:
raise ImproperlyConfigured('Error importing request processor module %s: "%s"' % (module, e))
try:
func = getattr(mod, attr)
except AttributeError:
raise ImproperlyConfigured('Module "%s" does not define a "%s" callable request processor' % (module, attr))
processors.append(func)
_standard_context_processors = tuple(processors)
return _standard_context_processors
class RequestContext(Context):
"""
This subclass of template.Context automatically populates itself using
the processors defined in TEMPLATE_CONTEXT_PROCESSORS.
Additional processors can be specified as a list of callables
using the "processors" keyword argument.
"""
def __init__(self, request, dict=None, processors=None, current_app=None):
Context.__init__(self, dict, current_app=current_app)
if processors is None:
processors = ()
else:
processors = tuple(processors)
for processor in get_standard_processors() + processors:
self.update(processor(request))
|
