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	for populating the reverse cache, since that may have been happening too early. git-svn-id: http://code.djangoproject.com/svn/django/trunk@5520 bcc190cf-cafb-0310-a4f2-bffc1f526a37
		
			
				
	
	
		
			271 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
			
		
		
	
	
			271 lines
		
	
	
		
			10 KiB
		
	
	
	
		
			Python
		
	
	
	
	
	
| """
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| This module converts requested URLs to callback view functions.
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| 
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| RegexURLResolver is the main class here. Its resolve() method takes a URL (as
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| a string) and returns a tuple in this format:
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| 
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|     (view_function, function_args, function_kwargs)
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| """
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| 
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| from django.http import Http404
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| from django.core.exceptions import ImproperlyConfigured, ViewDoesNotExist
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| from django.utils.functional import memoize
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| import re
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| 
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| try:
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|     reversed
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| except NameError:
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|     from django.utils.itercompat import reversed     # Python 2.3 fallback
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| 
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| _resolver_cache = {} # Maps urlconf modules to RegexURLResolver instances.
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| _callable_cache = {} # Maps view and url pattern names to their view functions.
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| 
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| class Resolver404(Http404):
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|     pass
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| 
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| class NoReverseMatch(Exception):
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|     # Don't make this raise an error when used in a template.
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|     silent_variable_failure = True
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| 
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| def get_callable(lookup_view):
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|     if not callable(lookup_view):
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|         mod_name, func_name = get_mod_func(lookup_view)
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|         if func_name != '':
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|             lookup_view = getattr(__import__(mod_name, {}, {}, ['']), func_name)
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|     return lookup_view
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| get_callable = memoize(get_callable, _callable_cache)
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| 
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| def get_resolver(urlconf):
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|     if urlconf is None:
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|         from django.conf import settings
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|         urlconf = settings.ROOT_URLCONF
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|     return RegexURLResolver(r'^/', urlconf)
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| get_resolver = memoize(get_resolver, _resolver_cache)
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| 
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| def get_mod_func(callback):
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|     # Converts 'django.views.news.stories.story_detail' to
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|     # ['django.views.news.stories', 'story_detail']
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|     try:
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|         dot = callback.rindex('.')
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|     except ValueError:
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|         return callback, ''
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|     return callback[:dot], callback[dot+1:]
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| 
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| def reverse_helper(regex, *args, **kwargs):
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|     """
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|     Does a "reverse" lookup -- returns the URL for the given args/kwargs.
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|     The args/kwargs are applied to the given compiled regular expression.
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|     For example:
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| 
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|         >>> reverse_helper(re.compile('^places/(\d+)/$'), 3)
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|         'places/3/'
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|         >>> reverse_helper(re.compile('^places/(?P<id>\d+)/$'), id=3)
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|         'places/3/'
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|         >>> reverse_helper(re.compile('^people/(?P<state>\w\w)/(\w+)/$'), 'adrian', state='il')
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|         'people/il/adrian/'
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| 
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|     Raises NoReverseMatch if the args/kwargs aren't valid for the regex.
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|     """
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|     # TODO: Handle nested parenthesis in the following regex.
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|     result = re.sub(r'\(([^)]+)\)', MatchChecker(args, kwargs), regex.pattern)
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|     return result.replace('^', '').replace('$', '')
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| 
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| class MatchChecker(object):
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|     "Class used in reverse RegexURLPattern lookup."
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|     def __init__(self, args, kwargs):
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|         self.args, self.kwargs = args, kwargs
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|         self.current_arg = 0
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| 
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|     def __call__(self, match_obj):
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|         # match_obj.group(1) is the contents of the parenthesis.
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|         # First we need to figure out whether it's a named or unnamed group.
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|         #
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|         grouped = match_obj.group(1)
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|         m = re.search(r'^\?P<(\w+)>(.*?)$', grouped)
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|         if m: # If this was a named group...
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|             # m.group(1) is the name of the group
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|             # m.group(2) is the regex.
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|             try:
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|                 value = self.kwargs[m.group(1)]
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|             except KeyError:
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|                 # It was a named group, but the arg was passed in as a
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|                 # positional arg or not at all.
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|                 try:
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|                     value = self.args[self.current_arg]
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|                     self.current_arg += 1
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|                 except IndexError:
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|                     # The arg wasn't passed in.
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|                     raise NoReverseMatch('Not enough positional arguments passed in')
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|             test_regex = m.group(2)
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|         else: # Otherwise, this was a positional (unnamed) group.
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|             try:
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|                 value = self.args[self.current_arg]
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|                 self.current_arg += 1
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|             except IndexError:
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|                 # The arg wasn't passed in.
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|                 raise NoReverseMatch('Not enough positional arguments passed in')
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|             test_regex = grouped
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|         # Note we're using re.match here on purpose because the start of
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|         # to string needs to match.
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|         if not re.match(test_regex + '$', str(value)): # TODO: Unicode?
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|             raise NoReverseMatch("Value %r didn't match regular expression %r" % (value, test_regex))
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|         return str(value) # TODO: Unicode?
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| 
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| class RegexURLPattern(object):
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|     def __init__(self, regex, callback, default_args=None, name=None):
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|         # regex is a string representing a regular expression.
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|         # callback is either a string like 'foo.views.news.stories.story_detail'
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|         # which represents the path to a module and a view function name, or a
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|         # callable object (view).
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|         self.regex = re.compile(regex)
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|         if callable(callback):
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|             self._callback = callback
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|         else:
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|             self._callback = None
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|             self._callback_str = callback
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|         self.default_args = default_args or {}
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|         self.name = name
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| 
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|     def add_prefix(self, prefix):
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|         """
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|         Adds the prefix string to a string-based callback.
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|         """
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|         if not prefix or not hasattr(self, '_callback_str'):
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|             return
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|         self._callback_str = prefix + '.' + self._callback_str
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| 
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|     def resolve(self, path):
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|         match = self.regex.search(path)
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|         if match:
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|             # If there are any named groups, use those as kwargs, ignoring
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|             # non-named groups. Otherwise, pass all non-named arguments as
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|             # positional arguments.
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|             kwargs = match.groupdict()
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|             if kwargs:
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|                 args = ()
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|             else:
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|                 args = match.groups()
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|             # In both cases, pass any extra_kwargs as **kwargs.
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|             kwargs.update(self.default_args)
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| 
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|             return self.callback, args, kwargs
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| 
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|     def _get_callback(self):
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|         if self._callback is not None:
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|             return self._callback
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|         try:
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|             self._callback = get_callable(self._callback_str)
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|         except ImportError, e:
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|             mod_name, _ = get_mod_func(self._callback_str)
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|             raise ViewDoesNotExist, "Could not import %s. Error was: %s" % (mod_name, str(e))
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|         except AttributeError, e:
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|             mod_name, func_name = get_mod_func(self._callback_str)
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|             raise ViewDoesNotExist, "Tried %s in module %s. Error was: %s" % (func_name, mod_name, str(e))
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|         return self._callback
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|     callback = property(_get_callback)
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| 
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|     def reverse(self, viewname, *args, **kwargs):
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|         mod_name, func_name = get_mod_func(viewname)
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|         try:
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|             lookup_view = getattr(__import__(mod_name, {}, {}, ['']), func_name)
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|         except (ImportError, AttributeError):
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|             raise NoReverseMatch
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|         if lookup_view != self.callback:
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|             raise NoReverseMatch
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|         return self.reverse_helper(*args, **kwargs)
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| 
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|     def reverse_helper(self, *args, **kwargs):
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|         return reverse_helper(self.regex, *args, **kwargs)
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| 
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| class RegexURLResolver(object):
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|     def __init__(self, regex, urlconf_name, default_kwargs=None):
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|         # regex is a string representing a regular expression.
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|         # urlconf_name is a string representing the module containing urlconfs.
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|         self.regex = re.compile(regex)
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|         self.urlconf_name = urlconf_name
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|         self.callback = None
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|         self.default_kwargs = default_kwargs or {}
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|         self._reverse_dict = {}
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| 
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|     def _get_reverse_dict(self):
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|         if not self._reverse_dict:
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|             for pattern in reversed(self.urlconf_module.urlpatterns):
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|                 if isinstance(pattern, RegexURLResolver):
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|                     for key, value in pattern.reverse_dict.iteritems():
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|                         self._reverse_dict[key] = (pattern,) + value
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|                 else:
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|                     self._reverse_dict[pattern.callback] = (pattern,)
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|                     self._reverse_dict[pattern.name] = (pattern,)
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|         return self._reverse_dict
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|     reverse_dict = property(_get_reverse_dict)
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| 
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|     def resolve(self, path):
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|         tried = []
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|         match = self.regex.search(path)
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|         if match:
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|             new_path = path[match.end():]
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|             for pattern in self.urlconf_module.urlpatterns:
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|                 try:
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|                     sub_match = pattern.resolve(new_path)
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|                 except Resolver404, e:
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|                     tried.extend([(pattern.regex.pattern + '   ' + t) for t in e.args[0]['tried']])
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|                 else:
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|                     if sub_match:
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|                         sub_match_dict = dict(self.default_kwargs, **sub_match[2])
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|                         return sub_match[0], sub_match[1], dict(match.groupdict(), **sub_match_dict)
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|                     tried.append(pattern.regex.pattern)
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|             raise Resolver404, {'tried': tried, 'path': new_path}
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| 
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|     def _get_urlconf_module(self):
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|         try:
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|             return self._urlconf_module
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|         except AttributeError:
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|             try:
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|                 self._urlconf_module = __import__(self.urlconf_name, {}, {}, [''])
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|             except ValueError, e:
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|                 # Invalid urlconf_name, such as "foo.bar." (note trailing period)
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|                 raise ImproperlyConfigured, "Error while importing URLconf %r: %s" % (self.urlconf_name, e)
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|             return self._urlconf_module
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|     urlconf_module = property(_get_urlconf_module)
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| 
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|     def _get_url_patterns(self):
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|         return self.urlconf_module.urlpatterns
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|     url_patterns = property(_get_url_patterns)
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| 
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|     def _resolve_special(self, view_type):
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|         callback = getattr(self.urlconf_module, 'handler%s' % view_type)
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|         mod_name, func_name = get_mod_func(callback)
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|         try:
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|             return getattr(__import__(mod_name, {}, {}, ['']), func_name), {}
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|         except (ImportError, AttributeError), e:
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|             raise ViewDoesNotExist, "Tried %s. Error was: %s" % (callback, str(e))
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| 
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|     def resolve404(self):
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|         return self._resolve_special('404')
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| 
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|     def resolve500(self):
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|         return self._resolve_special('500')
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| 
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|     def reverse(self, lookup_view, *args, **kwargs):
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|         try:
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|             lookup_view = get_callable(lookup_view)
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|         except (ImportError, AttributeError):
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|             raise NoReverseMatch
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|         if lookup_view in self.reverse_dict:
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|             return ''.join([reverse_helper(part.regex, *args, **kwargs) for part in self.reverse_dict[lookup_view]])
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|         raise NoReverseMatch
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| 
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|     def reverse_helper(self, lookup_view, *args, **kwargs):
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|         sub_match = self.reverse(lookup_view, *args, **kwargs)
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|         result = reverse_helper(self.regex, *args, **kwargs)
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|         return result + sub_match
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| 
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| def resolve(path, urlconf=None):
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|     return get_resolver(urlconf).resolve(path)
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| 
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| def reverse(viewname, urlconf=None, args=None, kwargs=None):
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|     args = args or []
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|     kwargs = kwargs or {}
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|     return '/' + get_resolver(urlconf).reverse(viewname, *args, **kwargs)
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| 
 |