""" 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.importlib import import_module 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_module(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, app_name=None, namespace=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 if not isinstance(urlconf_name, basestring): self._urlconf_module = self.urlconf_name self.callback = None self.default_kwargs = default_kwargs or {} self.namespace = namespace self.app_name = app_name self._reverse_dict = None self._namespace_dict = None self._app_dict = None def __repr__(self): return '<%s %s (%s:%s) %s>' % (self.__class__.__name__, self.urlconf_name, self.app_name, self.namespace, self.regex.pattern) def _populate(self): lookups = MultiValueDict() namespaces = {} apps = {} for pattern in reversed(self.url_patterns): p_pattern = pattern.regex.pattern if p_pattern.startswith('^'): p_pattern = p_pattern[1:] if isinstance(pattern, RegexURLResolver): if pattern.namespace: namespaces[pattern.namespace] = (p_pattern, pattern) if pattern.app_name: apps.setdefault(pattern.app_name, []).append(pattern.namespace) else: 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]) lookups.appendlist(name, (new_matches, p_pattern + pat)) for namespace, (prefix, sub_pattern) in pattern.namespace_dict.items(): namespaces[namespace] = (p_pattern + prefix, sub_pattern) for app_name, namespace_list in pattern.app_dict.items(): apps.setdefault(app_name, []).extend(namespace_list) else: bits = normalize(p_pattern) lookups.appendlist(pattern.callback, (bits, p_pattern)) lookups.appendlist(pattern.name, (bits, p_pattern)) self._reverse_dict = lookups self._namespace_dict = namespaces self._app_dict = apps def _get_reverse_dict(self): if self._reverse_dict is None: self._populate() return self._reverse_dict reverse_dict = property(_get_reverse_dict) def _get_namespace_dict(self): if self._namespace_dict is None: self._populate() return self._namespace_dict namespace_dict = property(_get_namespace_dict) def _get_app_dict(self): if self._app_dict is None: self._populate() return self._app_dict app_dict = property(_get_app_dict) def resolve(self, path): tried = [] match = self.regex.search(path) if match: new_path = path[match.end():] for pattern in self.url_patterns: try: sub_match = pattern.resolve(new_path) except Resolver404, e: sub_tried = e.args[0].get('tried') if sub_tried is not None: tried.extend([(pattern.regex.pattern + ' ' + t) for t in sub_tried]) else: tried.append(pattern.regex.pattern) 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} raise Resolver404, {'path' : path} def _get_urlconf_module(self): try: return self._urlconf_module except AttributeError: self._urlconf_module = import_module(self.urlconf_name) return self._urlconf_module urlconf_module = property(_get_urlconf_module) def _get_url_patterns(self): patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module) try: iter(patterns) except TypeError: raise ImproperlyConfigured("The included urlconf %s doesn't have any " "patterns in it" % self.urlconf_name) return patterns 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_module(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 # lookup_view can be URL label, or dotted path, or callable, Any of # these can be passed in at the top, but callables are not friendly in # error messages. m = getattr(lookup_view, '__module__', None) n = getattr(lookup_view, '__name__', None) if m is not None and n is not None: lookup_view_s = "%s.%s" % (m, n) else: lookup_view_s = lookup_view raise NoReverseMatch("Reverse for '%s' with arguments '%s' and keyword " "arguments '%s' not found." % (lookup_view_s, args, kwargs)) def resolve(path, urlconf=None): return get_resolver(urlconf).resolve(path) def reverse(viewname, urlconf=None, args=None, kwargs=None, prefix=None, current_app=None): resolver = get_resolver(urlconf) args = args or [] kwargs = kwargs or {} if prefix is None: prefix = get_script_prefix() if not isinstance(viewname, basestring): view = viewname else: parts = viewname.split(':') parts.reverse() view = parts[0] path = parts[1:] resolved_path = [] while path: ns = path.pop() # Lookup the name to see if it could be an app identifier try: app_list = resolver.app_dict[ns] # Yes! Path part matches an app in the current Resolver if current_app and current_app in app_list: # If we are reversing for a particular app, use that namespace ns = current_app elif ns not in app_list: # The name isn't shared by one of the instances (i.e., the default) # so just pick the first instance as the default. ns = app_list[0] except KeyError: pass try: extra, resolver = resolver.namespace_dict[ns] resolved_path.append(ns) prefix = prefix + extra except KeyError, key: if resolved_path: raise NoReverseMatch("%s is not a registered namespace inside '%s'" % (key, ':'.join(resolved_path))) else: raise NoReverseMatch("%s is not a registered namespace" % key) return iri_to_uri(u'%s%s' % (prefix, resolver.reverse(view, *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'/')