191 lines
7.6 KiB
Python
191 lines
7.6 KiB
Python
"""
|
|
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:]
|
|
|
|
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:
|
|
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):
|
|
"""
|
|
Does a "reverse" lookup -- returns the URL for the given args/kwargs.
|
|
The args/kwargs are applied to the regular expression in this
|
|
RegexURLPattern. For example:
|
|
|
|
>>> RegexURLPattern('^places/(\d+)/$').reverse_helper(3)
|
|
'places/3/'
|
|
>>> RegexURLPattern('^places/(?P<id>\d+)/$').reverse_helper(id=3)
|
|
'places/3/'
|
|
>>> RegexURLPattern('^people/(?P<state>\w\w)/(\w+)/$').reverse_helper('adrian', state='il')
|
|
'people/il/adrian/'
|
|
|
|
Raises NoReverseMatch if the args/kwargs aren't valid for the RegexURLPattern.
|
|
"""
|
|
# TODO: Handle nested parenthesis in the following regex.
|
|
result = re.sub(r'\(([^)]+)\)', MatchChecker(args, kwargs), self.regex.pattern)
|
|
return result.replace('^', '').replace('$', '')
|
|
|
|
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 pattern.callback == viewname:
|
|
try:
|
|
return pattern.reverse_helper(*args, **kwargs)
|
|
except NoReverseMatch:
|
|
continue
|
|
raise NoReverseMatch
|