Source code for django.urls.resolvers

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 ResolverMatch object which provides access to all
attributes of the resolved URL match.
from __future__ import unicode_literals

import functools
import re
import threading
from importlib import import_module

from django.conf import settings
from django.core.exceptions import ImproperlyConfigured
from django.utils import lru_cache, six
from django.utils.datastructures import MultiValueDict
from django.utils.encoding import force_str, force_text
from django.utils.functional import cached_property
from django.utils.http import RFC3986_SUBDELIMS, urlquote
from django.utils.regex_helper import normalize
from django.utils.translation import get_language

from .exceptions import NoReverseMatch, Resolver404
from .utils import get_callable

[docs]class ResolverMatch(object): def __init__(self, func, args, kwargs, url_name=None, app_names=None, namespaces=None): self.func = func self.args = args self.kwargs = kwargs self.url_name = url_name # If a URLRegexResolver doesn't have a namespace or app_name, it passes # in an empty value. self.app_names = [x for x in app_names if x] if app_names else [] self.app_name = ':'.join(self.app_names) self.namespaces = [x for x in namespaces if x] if namespaces else [] self.namespace = ':'.join(self.namespaces) if not hasattr(func, '__name__'): # A class-based view self._func_path = '.'.join([func.__class__.__module__, func.__class__.__name__]) else: # A function-based view self._func_path = '.'.join([func.__module__, func.__name__]) view_path = url_name or self._func_path self.view_name = ':'.join(self.namespaces + [view_path]) def __getitem__(self, index): return (self.func, self.args, self.kwargs)[index] def __repr__(self): return "ResolverMatch(func=%s, args=%s, kwargs=%s, url_name=%s, app_names=%s, namespaces=%s)" % ( self._func_path, self.args, self.kwargs, self.url_name, self.app_names, self.namespaces, )
@lru_cache.lru_cache(maxsize=None) def get_resolver(urlconf=None): if urlconf is None: from django.conf import settings urlconf = settings.ROOT_URLCONF return RegexURLResolver(r'^/', urlconf) @lru_cache.lru_cache(maxsize=None) def get_ns_resolver(ns_pattern, resolver): # Build a namespaced resolver for the given parent URLconf pattern. # This makes it possible to have captured parameters in the parent # URLconf pattern. ns_resolver = RegexURLResolver(ns_pattern, resolver.url_patterns) return RegexURLResolver(r'^/', [ns_resolver]) class LocaleRegexProvider(object): """ A mixin to provide a default regex property which can vary by active language. """ def __init__(self, regex): # regex is either a string representing a regular expression, or a # translatable string (using ugettext_lazy) representing a regular # expression. self._regex = regex self._regex_dict = {} @property def regex(self): """ Return a compiled regular expression based on the activate language. """ language_code = get_language() if language_code not in self._regex_dict: regex = self._regex if isinstance(self._regex, six.string_types) else force_text(self._regex) try: compiled_regex = re.compile(regex, re.UNICODE) except re.error as e: raise ImproperlyConfigured( '"%s" is not a valid regular expression: %s' % (regex, six.text_type(e)) ) self._regex_dict[language_code] = compiled_regex return self._regex_dict[language_code] class RegexURLPattern(LocaleRegexProvider): def __init__(self, regex, callback, default_args=None, name=None): LocaleRegexProvider.__init__(self, regex) self.callback = callback # the view self.default_args = default_args or {} = name def __repr__(self): return force_str('<%s %s %s>' % (self.__class__.__name__,, self.regex.pattern)) def resolve(self, path): match = 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() args = () if kwargs else match.groups() # In both cases, pass any extra_kwargs as **kwargs. kwargs.update(self.default_args) return ResolverMatch(self.callback, args, kwargs, @cached_property def lookup_str(self): """ A string that identifies the view (e.g. '' or ''). """ callback = self.callback # Python 3.5 collapses nested partials, so can change "while" to "if" # when it's the minimum supported version. while isinstance(callback, functools.partial): callback = callback.func if not hasattr(callback, '__name__'): return callback.__module__ + "." + callback.__class__.__name__ elif six.PY3: return callback.__module__ + "." + callback.__qualname__ else: # PY2 does not support __qualname__ return callback.__module__ + "." + callback.__name__ class RegexURLResolver(LocaleRegexProvider): def __init__(self, regex, urlconf_name, default_kwargs=None, app_name=None, namespace=None): LocaleRegexProvider.__init__(self, regex) # urlconf_name is the dotted Python path to the module defining # urlpatterns. It may also be an object with an urlpatterns attribute # or urlpatterns itself. self.urlconf_name = urlconf_name self.callback = None self.default_kwargs = default_kwargs or {} self.namespace = namespace self.app_name = app_name self._reverse_dict = {} self._namespace_dict = {} self._app_dict = {} # set of dotted paths to all functions and classes that are used in # urlpatterns self._callback_strs = set() self._populated = False self._local = threading.local() def __repr__(self): if isinstance(self.urlconf_name, list) and len(self.urlconf_name): # Don't bother to output the whole list, it can be huge urlconf_repr = '<%s list>' % self.urlconf_name[0].__class__.__name__ else: urlconf_repr = repr(self.urlconf_name) return str('<%s %s (%s:%s) %s>') % ( self.__class__.__name__, urlconf_repr, self.app_name, self.namespace, self.regex.pattern, ) def _populate(self): # Short-circuit if called recursively in this thread to prevent # infinite recursion. Concurrent threads may call this at the same # time and will need to continue, so set 'populating' on a # thread-local variable. if getattr(self._local, 'populating', False): return self._local.populating = True lookups = MultiValueDict() namespaces = {} apps = {} language_code = get_language() for pattern in reversed(self.url_patterns): if isinstance(pattern, RegexURLPattern): self._callback_strs.add(pattern.lookup_str) 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_pat = pattern.regex.pattern for name in pattern.reverse_dict: for matches, pat, defaults in pattern.reverse_dict.getlist(name): new_matches = normalize(parent_pat + pat) lookups.appendlist( name, ( new_matches, p_pattern + pat, dict(defaults, **pattern.default_kwargs), ) ) 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) if not getattr(pattern._local, 'populating', False): pattern._populate() self._callback_strs.update(pattern._callback_strs) else: bits = normalize(p_pattern) lookups.appendlist(pattern.callback, (bits, p_pattern, pattern.default_args)) if is not None: lookups.appendlist(, (bits, p_pattern, pattern.default_args)) self._reverse_dict[language_code] = lookups self._namespace_dict[language_code] = namespaces self._app_dict[language_code] = apps self._populated = True self._local.populating = False @property def reverse_dict(self): language_code = get_language() if language_code not in self._reverse_dict: self._populate() return self._reverse_dict[language_code] @property def namespace_dict(self): language_code = get_language() if language_code not in self._namespace_dict: self._populate() return self._namespace_dict[language_code] @property def app_dict(self): language_code = get_language() if language_code not in self._app_dict: self._populate() return self._app_dict[language_code] def _is_callback(self, name): if not self._populated: self._populate() return name in self._callback_strs def resolve(self, path): path = force_text(path) # path may be a reverse_lazy object tried = [] match = if match: new_path = path[match.end():] for pattern in self.url_patterns: try: sub_match = pattern.resolve(new_path) except Resolver404 as e: sub_tried = e.args[0].get('tried') if sub_tried is not None: tried.extend([pattern] + t for t in sub_tried) else: tried.append([pattern]) else: if sub_match: # Merge captured arguments in match with submatch sub_match_dict = dict(match.groupdict(), **self.default_kwargs) sub_match_dict.update(sub_match.kwargs) # If there are *any* named groups, ignore all non-named groups. # Otherwise, pass all non-named arguments as positional arguments. sub_match_args = sub_match.args if not sub_match_dict: sub_match_args = match.groups() + sub_match.args return ResolverMatch( sub_match.func, sub_match_args, sub_match_dict, sub_match.url_name, [self.app_name] + sub_match.app_names, [self.namespace] + sub_match.namespaces, ) tried.append([pattern]) raise Resolver404({'tried': tried, 'path': new_path}) raise Resolver404({'path': path}) @cached_property def urlconf_module(self): if isinstance(self.urlconf_name, six.string_types): return import_module(self.urlconf_name) else: return self.urlconf_name @cached_property def url_patterns(self): # urlconf_module might be a valid set of patterns, so we default to it patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module) try: iter(patterns) except TypeError: msg = ( "The included URLconf '{name}' does not appear to have any " "patterns in it. If you see valid patterns in the file then " "the issue is probably caused by a circular import." ) raise ImproperlyConfigured(msg.format(name=self.urlconf_name)) return patterns def resolve_error_handler(self, view_type): callback = getattr(self.urlconf_module, 'handler%s' % view_type, None) if not callback: # No handler specified in file; use lazy import, since # django.conf.urls imports this file. from django.conf import urls callback = getattr(urls, 'handler%s' % view_type) return get_callable(callback), {} def reverse(self, lookup_view, *args, **kwargs): return self._reverse_with_prefix(lookup_view, '', *args, **kwargs) def _reverse_with_prefix(self, lookup_view, _prefix, *args, **kwargs): if args and kwargs: raise ValueError("Don't mix *args and **kwargs in call to reverse()!") text_args = [force_text(v) for v in args] text_kwargs = {k: force_text(v) for (k, v) in kwargs.items()} if not self._populated: self._populate() possibilities = self.reverse_dict.getlist(lookup_view) for possibility, pattern, defaults in possibilities: for result, params in possibility: if args: if len(args) != len(params): continue candidate_subs = dict(zip(params, text_args)) else: if (set(kwargs.keys()) | set(defaults.keys()) != set(params) | set(defaults.keys())): continue matches = True for k, v in defaults.items(): if kwargs.get(k, v) != v: matches = False break if not matches: continue candidate_subs = text_kwargs # WSGI provides decoded URLs, without %xx escapes, and the URL # resolver operates on such URLs. First substitute arguments # without quoting to build a decoded URL and look for a match. # Then, if we have a match, redo the substitution with quoted # arguments in order to return a properly encoded URL. candidate_pat = _prefix.replace('%', '%%') + result if'^%s%s' % (re.escape(_prefix), pattern), candidate_pat % candidate_subs, re.UNICODE): # safe characters from `pchar` definition of RFC 3986 url = urlquote(candidate_pat % candidate_subs, safe=RFC3986_SUBDELIMS + str('/~:@')) # Don't allow construction of scheme relative urls. if url.startswith('//'): url = '/%%2F%s' % url[2:] return url # lookup_view can be URL name or callable, 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 patterns = [pattern for (possibility, pattern, defaults) in possibilities] raise NoReverseMatch( "Reverse for '%s' with arguments '%s' and keyword " "arguments '%s' not found. %d pattern(s) tried: %s" % (lookup_view_s, args, kwargs, len(patterns), patterns) ) class LocaleRegexURLResolver(RegexURLResolver): """ A URL resolver that always matches the active language code as URL prefix. Rather than taking a regex argument, we just override the ``regex`` function to always return the active language-code as regex. """ def __init__( self, urlconf_name, default_kwargs=None, app_name=None, namespace=None, prefix_default_language=True, ): super(LocaleRegexURLResolver, self).__init__( None, urlconf_name, default_kwargs, app_name, namespace, ) self.prefix_default_language = prefix_default_language @property def regex(self): language_code = get_language() or settings.LANGUAGE_CODE if language_code not in self._regex_dict: if language_code == settings.LANGUAGE_CODE and not self.prefix_default_language: regex_string = '' else: regex_string = '^%s/' % language_code self._regex_dict[language_code] = re.compile(regex_string, re.UNICODE) return self._regex_dict[language_code]
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