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
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
|
"""
This module converts requested URLs to callback view functions.
RegexURLResolver is the main class here. Its resolve() method takes a URL (as
a string) and returns a tuple in this format:
(view_function, function_args, function_kwargs)
"""
from django.http import Http404
from django.core.exceptions import ImproperlyConfigured, ViewDoesNotExist
import re
class Resolver404(Http404):
pass
class NoReverseMatch(Exception):
pass
def get_mod_func(callback):
# Converts 'django.views.news.stories.story_detail' to
# ['django.views.news.stories', 'story_detail']
dot = callback.rindex('.')
return callback[:dot], callback[dot+1:]
def reverse_helper(regex, *args, **kwargs):
"""
Does a "reverse" lookup -- returns the URL for the given args/kwargs.
The args/kwargs are applied to the given compiled regular expression.
For example:
>>> reverse_helper(re.compile('^places/(\d+)/$'), 3)
'places/3/'
>>> reverse_helper(re.compile('^places/(?P<id>\d+)/$'), id=3)
'places/3/'
>>> reverse_helper(re.compile('^people/(?P<state>\w\w)/(\w+)/$'), 'adrian', state='il')
'people/il/adrian/'
Raises NoReverseMatch if the args/kwargs aren't valid for the regex.
"""
# TODO: Handle nested parenthesis in the following regex.
result = re.sub(r'\(([^)]+)\)', MatchChecker(args, kwargs), regex.pattern)
return result.replace('^', '').replace('$', '')
class MatchChecker(object):
"Class used in reverse RegexURLPattern lookup."
def __init__(self, args, kwargs):
self.args, self.kwargs = args, kwargs
self.current_arg = 0
def __call__(self, match_obj):
# match_obj.group(1) is the contents of the parenthesis.
# First we need to figure out whether it's a named or unnamed group.
#
grouped = match_obj.group(1)
m = re.search(r'^\?P<(\w+)>(.*?)$', grouped)
if m: # If this was a named group...
# m.group(1) is the name of the group
# m.group(2) is the regex.
try:
value = self.kwargs[m.group(1)]
except KeyError:
# It was a named group, but the arg was passed in as a
# positional arg or not at all.
try:
value = self.args[self.current_arg]
self.current_arg += 1
except IndexError:
# The arg wasn't passed in.
raise NoReverseMatch('Not enough positional arguments passed in')
test_regex = m.group(2)
else: # Otherwise, this was a positional (unnamed) group.
try:
value = self.args[self.current_arg]
self.current_arg += 1
except IndexError:
# The arg wasn't passed in.
raise NoReverseMatch('Not enough positional arguments passed in')
test_regex = grouped
# Note we're using re.match here on purpose because the start of
# to string needs to match.
if not re.match(test_regex + '$', str(value)): # TODO: Unicode?
raise NoReverseMatch("Value %r didn't match regular expression %r" % (value, test_regex))
return str(value) # TODO: Unicode?
class RegexURLPattern(object):
def __init__(self, regex, callback, default_args=None):
# regex is a string representing a regular expression.
# callback is something like 'foo.views.news.stories.story_detail',
# which represents the path to a module and a view function name.
self.regex = re.compile(regex)
self.callback = callback
self.default_args = default_args or {}
def resolve(self, path):
match = self.regex.search(path)
if match:
# If there are any named groups, use those as kwargs, ignoring
# non-named groups. Otherwise, pass all non-named arguments as
# positional arguments.
kwargs = match.groupdict()
if kwargs:
args = ()
if not kwargs:
args = match.groups()
# In both cases, pass any extra_kwargs as **kwargs.
kwargs.update(self.default_args)
try: # Lazily load self.func.
return self.func, args, kwargs
except AttributeError:
self.func = self.get_callback()
return self.func, args, kwargs
def get_callback(self):
mod_name, func_name = get_mod_func(self.callback)
try:
return getattr(__import__(mod_name, '', '', ['']), func_name)
except ImportError, e:
raise ViewDoesNotExist, "Could not import %s. Error was: %s" % (mod_name, str(e))
except AttributeError, e:
raise ViewDoesNotExist, "Tried %s in module %s. Error was: %s" % (func_name, mod_name, str(e))
def reverse(self, viewname, *args, **kwargs):
if viewname != self.callback:
raise NoReverseMatch
return self.reverse_helper(*args, **kwargs)
def reverse_helper(self, *args, **kwargs):
return reverse_helper(self.regex, *args, **kwargs)
class RegexURLResolver(object):
def __init__(self, regex, urlconf_name):
# regex is a string representing a regular expression.
# urlconf_name is a string representing the module containing urlconfs.
self.regex = re.compile(regex)
self.urlconf_name = urlconf_name
self.callback = None
def resolve(self, path):
tried = []
match = self.regex.search(path)
if match:
new_path = path[match.end():]
for pattern in self.urlconf_module.urlpatterns:
try:
sub_match = pattern.resolve(new_path)
except Resolver404, e:
tried.extend([(pattern.regex.pattern + ' ' + t) for t in e.args[0]['tried']])
else:
if sub_match:
return sub_match[0], sub_match[1], dict(match.groupdict(), **sub_match[2])
tried.append(pattern.regex.pattern)
raise Resolver404, {'tried': tried, 'path': new_path}
def _get_urlconf_module(self):
try:
return self._urlconf_module
except AttributeError:
try:
self._urlconf_module = __import__(self.urlconf_name, '', '', [''])
except ValueError, e:
# Invalid urlconf_name, such as "foo.bar." (note trailing period)
raise ImproperlyConfigured, "Error while importing URLconf %r: %s" % (self.urlconf_name, e)
return self._urlconf_module
urlconf_module = property(_get_urlconf_module)
def _get_url_patterns(self):
return self.urlconf_module.urlpatterns
url_patterns = property(_get_url_patterns)
def _resolve_special(self, view_type):
callback = getattr(self.urlconf_module, 'handler%s' % view_type)
mod_name, func_name = get_mod_func(callback)
try:
return getattr(__import__(mod_name, '', '', ['']), func_name), {}
except (ImportError, AttributeError), e:
raise ViewDoesNotExist, "Tried %s. Error was: %s" % (callback, str(e))
def resolve404(self):
return self._resolve_special('404')
def resolve500(self):
return self._resolve_special('500')
def reverse(self, viewname, *args, **kwargs):
for pattern in self.urlconf_module.urlpatterns:
if isinstance(pattern, RegexURLResolver):
try:
return pattern.reverse_helper(viewname, *args, **kwargs)
except NoReverseMatch:
continue
elif pattern.callback == viewname:
try:
return pattern.reverse_helper(*args, **kwargs)
except NoReverseMatch:
continue
raise NoReverseMatch
def reverse_helper(self, viewname, *args, **kwargs):
sub_match = self.reverse(viewname, *args, **kwargs)
result = reverse_helper(self.regex, *args, **kwargs)
return result + sub_match
def resolve(path, urlconf=None):
if urlconf is None:
from django.conf import settings
urlconf = settings.ROOT_URLCONF
resolver = RegexURLResolver(r'^/', urlconf)
return resolver.resolve(path)
def reverse(viewname, urlconf=None, args=None, kwargs=None):
args = args or []
kwargs = kwargs or {}
if urlconf is None:
from django.conf import settings
urlconf = settings.ROOT_URLCONF
resolver = RegexURLResolver(r'^/', urlconf)
return '/' + resolver.reverse(viewname, *args, **kwargs)
|
