+
−"""
+
−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)
+
−"""
+
−
+
−import re
+
−
+
−from django.http import Http404
+
−from django.core.exceptions import ImproperlyConfigured, ViewDoesNotExist
+
−from django.utils.datastructures import MultiValueDict
+
−from django.utils.encoding import iri_to_uri, force_unicode, smart_str
+
−from django.utils.functional import memoize
+
−from django.utils.regex_helper import normalize
+
−from django.utils.thread_support import currentThread
+
−
+
−try:
+
−    reversed
+
−except NameError:
+
−    from django.utils.itercompat import reversed     # Python 2.3 fallback
+
−    from sets import Set as set
+
−
+
−_resolver_cache = {} # Maps urlconf modules to RegexURLResolver instances.
+
−_callable_cache = {} # Maps view and url pattern names to their view functions.
+
−
+
−# SCRIPT_NAME prefixes for each thread are stored here. If there's no entry for
+
−# the current thread (which is the only one we ever access), it is assumed to
+
−# be empty.
+
−_prefixes = {}
+
−
+
−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)
+
−                if not callable(lookup_view):
+
−                    raise AttributeError("'%s.%s' is not a callable." % (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:]
+
−
+
−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)
+
−
+
−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 = MultiValueDict()
+
−
+
−    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):
+
−                p_pattern = pattern.regex.pattern
+
−                if p_pattern.startswith('^'):
+
−                    p_pattern = p_pattern[1:]
+
−                if isinstance(pattern, RegexURLResolver):
+
−                    parent = normalize(pattern.regex.pattern)
+
−                    for name in pattern.reverse_dict:
+
−                        for matches, pat in pattern.reverse_dict.getlist(name):
+
−                            new_matches = []
+
−                            for piece, p_args in parent:
+
−                                new_matches.extend([(piece + suffix, p_args + args) for (suffix, args) in matches])
+
−                            self._reverse_dict.appendlist(name, (new_matches, p_pattern + pat))
+
−                else:
+
−                    bits = normalize(p_pattern)
+
−                    self._reverse_dict.appendlist(pattern.callback, (bits, p_pattern))
+
−                    self._reverse_dict.appendlist(pattern.name, (bits, p_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:
+
−            self._urlconf_module = __import__(self.urlconf_name, {}, {}, [''])
+
−            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):
+
−        if args and kwargs:
+
−            raise ValueError("Don't mix *args and **kwargs in call to reverse()!")
+
−        try:
+
−            lookup_view = get_callable(lookup_view, True)
+
−        except (ImportError, AttributeError), e:
+
−            raise NoReverseMatch("Error importing '%s': %s." % (lookup_view, e))
+
−        possibilities = self.reverse_dict.getlist(lookup_view)
+
−        for possibility, pattern in possibilities:
+
−            for result, params in possibility:
+
−                if args:
+
−                    if len(args) != len(params):
+
−                        continue
+
−                    unicode_args = [force_unicode(val) for val in args]
+
−                    candidate =  result % dict(zip(params, unicode_args))
+
−                else:
+
−                    if set(kwargs.keys()) != set(params):
+
−                        continue
+
−                    unicode_kwargs = dict([(k, force_unicode(v)) for (k, v) in kwargs.items()])
+
−                    candidate = result % unicode_kwargs
+
−                if re.search(u'^%s' % pattern, candidate, re.UNICODE):
+
−                    return candidate
+
−        raise NoReverseMatch("Reverse for '%s' with arguments '%s' and keyword "
+
−                "arguments '%s' not found." % (lookup_view, args, kwargs))
+
−
+
−def resolve(path, urlconf=None):
+
−    return get_resolver(urlconf).resolve(path)
+
−
+
−def reverse(viewname, urlconf=None, args=None, kwargs=None, prefix=None):
+
−    args = args or []
+
−    kwargs = kwargs or {}
+
−    if prefix is None:
+
−        prefix = get_script_prefix()
+
−    return iri_to_uri(u'%s%s' % (prefix, get_resolver(urlconf).reverse(viewname,
+
−            *args, **kwargs)))
+
−
+
−def clear_url_caches():
+
−    global _resolver_cache
+
−    global _callable_cache
+
−    _resolver_cache.clear()
+
−    _callable_cache.clear()
+
−
+
−def set_script_prefix(prefix):
+
−    """
+
−    Sets the script prefix for the current thread.
+
−    """
+
−    if not prefix.endswith('/'):
+
−        prefix += '/'
+
−    _prefixes[currentThread()] = prefix
+
−
+
−def get_script_prefix():
+
−    """
+
−    Returns the currently active script prefix. Useful for client code that
+
−    wishes to construct their own URLs manually (although accessing the request
+
−    instance is normally going to be a lot cleaner).
+
−    """
+
−    return _prefixes.get(currentThread(), u'/')
+
−