diff -r 57b4279d8c4e -r 03e267d67478 app/django/core/urlresolvers.py
--- /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))
+