| """ |
| 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.encoding import iri_to_uri, force_unicode, smart_str |
| from django.utils.functional import memoize |
| from django.utils.thread_support import currentThread |
| |
| 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. |
| |
| # 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) |
| 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('$', '').replace('\\', '') |
| |
| class MatchChecker(object): |
| "Class used in reverse RegexURLPattern lookup." |
| def __init__(self, args, kwargs): |
| self.args, self.kwargs = args, kwargs |
| self.current_arg = 0 |
| |
| def __call__(self, match_obj): |
| # match_obj.group(1) is the contents of the parenthesis. |
| # First we need to figure out whether it's a named or unnamed group. |
| # |
| grouped = match_obj.group(1) |
| m = re.search(r'^\?P<(\w+)>(.*?)$', 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("'%s' is not a callable." % lookup_view) |
| 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("Reverse for '%s' not found." % lookup_view) |
| |
| 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, 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'/') |
| |
