--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/app/django/core/urlresolvers.py Fri Jul 18 18:22:23 2008 +0000
@@ -0,0 +1,298 @@
+"""
+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
+from django.utils.encoding import iri_to_uri, force_unicode, smart_str
+from django.utils.functional import memoize
+import re
+
+try:
+ reversed
+except NameError:
+ from django.utils.itercompat import reversed # Python 2.3 fallback
+
+_resolver_cache = {} # Maps urlconf modules to RegexURLResolver instances.
+_callable_cache = {} # Maps view and url pattern names to their view functions.
+
+class Resolver404(Http404):
+ pass
+
+class NoReverseMatch(Exception):
+ # Don't make this raise an error when used in a template.
+ silent_variable_failure = True
+
+def get_callable(lookup_view, can_fail=False):
+ """
+ Convert a string version of a function name to the callable object.
+
+ If the lookup_view is not an import path, it is assumed to be a URL pattern
+ label and the original string is returned.
+
+ If can_fail is True, lookup_view might be a URL pattern label, so errors
+ during the import fail and the string is returned.
+ """
+ if not callable(lookup_view):
+ try:
+ # Bail early for non-ASCII strings (they can't be functions).
+ lookup_view = lookup_view.encode('ascii')
+ mod_name, func_name = get_mod_func(lookup_view)
+ if func_name != '':
+ lookup_view = getattr(__import__(mod_name, {}, {}, ['']), func_name)
+ except (ImportError, AttributeError):
+ if not can_fail:
+ raise
+ except UnicodeEncodeError:
+ pass
+ return lookup_view
+get_callable = memoize(get_callable, _callable_cache, 1)
+
+def get_resolver(urlconf):
+ if urlconf is None:
+ from django.conf import settings
+ urlconf = settings.ROOT_URLCONF
+ return RegexURLResolver(r'^/', urlconf)
+get_resolver = memoize(get_resolver, _resolver_cache, 1)
+
+def get_mod_func(callback):
+ # Converts 'django.views.news.stories.story_detail' to
+ # ['django.views.news.stories', 'story_detail']
+ try:
+ dot = callback.rindex('.')
+ except ValueError:
+ return callback, ''
+ 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, re.UNICODE)
+ 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 + '$', force_unicode(value), re.UNICODE):
+ raise NoReverseMatch("Value %r didn't match regular expression %r" % (value, test_regex))
+ return force_unicode(value)
+
+class RegexURLPattern(object):
+ def __init__(self, regex, callback, default_args=None, name=None):
+ # regex is a string representing a regular expression.
+ # callback is either a string like 'foo.views.news.stories.story_detail'
+ # which represents the path to a module and a view function name, or a
+ # callable object (view).
+ self.regex = re.compile(regex, re.UNICODE)
+ if callable(callback):
+ self._callback = callback
+ else:
+ self._callback = None
+ self._callback_str = callback
+ self.default_args = default_args or {}
+ self.name = name
+
+ def __repr__(self):
+ return '<%s %s %s>' % (self.__class__.__name__, self.name, self.regex.pattern)
+
+ def add_prefix(self, prefix):
+ """
+ Adds the prefix string to a string-based callback.
+ """
+ if not prefix or not hasattr(self, '_callback_str'):
+ return
+ self._callback_str = prefix + '.' + self._callback_str
+
+ 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 = ()
+ else:
+ args = match.groups()
+ # In both cases, pass any extra_kwargs as **kwargs.
+ kwargs.update(self.default_args)
+
+ return self.callback, args, kwargs
+
+ def _get_callback(self):
+ if self._callback is not None:
+ return self._callback
+ try:
+ self._callback = get_callable(self._callback_str)
+ except ImportError, e:
+ mod_name, _ = get_mod_func(self._callback_str)
+ raise ViewDoesNotExist, "Could not import %s. Error was: %s" % (mod_name, str(e))
+ except AttributeError, e:
+ mod_name, func_name = get_mod_func(self._callback_str)
+ raise ViewDoesNotExist, "Tried %s in module %s. Error was: %s" % (func_name, mod_name, str(e))
+ return self._callback
+ callback = property(_get_callback)
+
+ def reverse(self, viewname, *args, **kwargs):
+ mod_name, func_name = get_mod_func(viewname)
+ try:
+ lookup_view = getattr(__import__(mod_name, {}, {}, ['']), func_name)
+ except (ImportError, AttributeError):
+ raise NoReverseMatch
+ if lookup_view != 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, default_kwargs=None):
+ # regex is a string representing a regular expression.
+ # urlconf_name is a string representing the module containing urlconfs.
+ self.regex = re.compile(regex, re.UNICODE)
+ self.urlconf_name = urlconf_name
+ self.callback = None
+ self.default_kwargs = default_kwargs or {}
+ self._reverse_dict = {}
+
+ def __repr__(self):
+ return '<%s %s %s>' % (self.__class__.__name__, self.urlconf_name, self.regex.pattern)
+
+ def _get_reverse_dict(self):
+ if not self._reverse_dict and hasattr(self.urlconf_module, 'urlpatterns'):
+ for pattern in reversed(self.urlconf_module.urlpatterns):
+ if isinstance(pattern, RegexURLResolver):
+ for key, value in pattern.reverse_dict.iteritems():
+ self._reverse_dict[key] = (pattern,) + value
+ else:
+ self._reverse_dict[pattern.callback] = (pattern,)
+ self._reverse_dict[pattern.name] = (pattern,)
+ return self._reverse_dict
+ reverse_dict = property(_get_reverse_dict)
+
+ 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:
+ sub_match_dict = dict([(smart_str(k), v) for k, v in match.groupdict().items()])
+ sub_match_dict.update(self.default_kwargs)
+ for k, v in sub_match[2].iteritems():
+ sub_match_dict[smart_str(k)] = v
+ return sub_match[0], sub_match[1], sub_match_dict
+ 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 Exception, e:
+ # Either an invalid urlconf_name, such as "foo.bar.", or some
+ # kind of problem during the actual import.
+ 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, lookup_view, *args, **kwargs):
+ try:
+ lookup_view = get_callable(lookup_view, True)
+ except (ImportError, AttributeError):
+ raise NoReverseMatch
+ if lookup_view in self.reverse_dict:
+ return u''.join([reverse_helper(part.regex, *args, **kwargs) for part in self.reverse_dict[lookup_view]])
+ raise NoReverseMatch
+
+ def reverse_helper(self, lookup_view, *args, **kwargs):
+ sub_match = self.reverse(lookup_view, *args, **kwargs)
+ result = reverse_helper(self.regex, *args, **kwargs)
+ return result + sub_match
+
+def resolve(path, urlconf=None):
+ return get_resolver(urlconf).resolve(path)
+
+def reverse(viewname, urlconf=None, args=None, kwargs=None):
+ args = args or []
+ kwargs = kwargs or {}
+ return iri_to_uri(u'/' + get_resolver(urlconf).reverse(viewname, *args, **kwargs))
+