Refactored the internals of URL parsing to use less code

git-svn-id: http://code.djangoproject.com/svn/django/trunk@411 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/conf/urls/defaults.py

@@ -1,4 +1,4 @@
-from django.core.urlresolvers import RegexURLMultiplePattern, RegexURLPattern
+from django.core.urlresolvers import RegexURLPattern, RegexURLResolver
 
 __all__ = ['handler404', 'handler500', 'include', 'patterns']
 
@@ -11,7 +11,7 @@ def patterns(prefix, *tuples):
     pattern_list = []
     for t in tuples:
         if type(t[1]) == list:
-            pattern_list.append(RegexURLMultiplePattern(t[0], t[1][0]))
+            pattern_list.append(RegexURLResolver(t[0], t[1][0]))
         else:
             pattern_list.append(RegexURLPattern(t[0], prefix and (prefix + '.' + t[1]) or t[1], *t[2:]))
     return pattern_list

django/core/handlers/base.py

@@ -51,8 +51,7 @@ class BaseHandler:
             if response:
                 return response
 
-        conf_module = __import__(ROOT_URLCONF, '', '', [''])
+        resolver = urlresolvers.RegexURLResolver(r'^/', ROOT_URLCONF)
-        resolver = urlresolvers.RegexURLResolver(conf_module.urlpatterns)
         try:
             callback, param_dict = resolver.resolve(path)
             # Apply view middleware
@@ -65,8 +64,7 @@ class BaseHandler:
             if DEBUG:
                 return self.get_technical_error_response(is404=True)
             else:
-                resolver = urlresolvers.Error404Resolver(conf_module.handler404)
+                callback, param_dict = resolver.resolve404()
-                callback, param_dict = resolver.resolve()
                 return callback(request, **param_dict)
         except db.DatabaseError:
             db.db.rollback()
@@ -76,7 +74,7 @@ class BaseHandler:
                 subject = 'Database error (%s IP)' % (request.META['REMOTE_ADDR'] in INTERNAL_IPS and 'internal' or 'EXTERNAL')
                 message = "%s\n\n%s" % (self._get_traceback(), request)
                 mail_admins(subject, message, fail_silently=True)
-                return self.get_friendly_error_response(request, conf_module)
+                return self.get_friendly_error_response(request, resolver)
         except exceptions.PermissionDenied:
             return httpwrappers.HttpResponseForbidden('<h1>Permission denied</h1>')
         except: # Handle everything else, including SuspiciousOperation, etc.
@@ -90,16 +88,15 @@ class BaseHandler:
                     request_repr = "Request repr() unavailable"
                 message = "%s\n\n%s" % (self._get_traceback(), request_repr)
                 mail_admins(subject, message, fail_silently=True)
-                return self.get_friendly_error_response(request, conf_module)
+                return self.get_friendly_error_response(request, resolver)
 
-    def get_friendly_error_response(self, request, conf_module):
+    def get_friendly_error_response(self, request, resolver):
         """
         Returns an HttpResponse that displays a PUBLIC error message for a
         fundamental database or coding error.
         """
         from django.core import urlresolvers
-        resolver = urlresolvers.Error404Resolver(conf_module.handler500)
+        callback, param_dict = resolver.resolve500()
-        callback, param_dict = resolver.resolve()
         return callback(request, **param_dict)
 
     def get_technical_error_response(self, is404=False):

django/core/urlresolvers.py

@@ -18,13 +18,14 @@ def get_mod_func(callback):
 
 class RegexURLPattern:
     def __init__(self, regex, callback, default_args=None):
-        self.regex = re.compile(regex)
+        # regex is a string representing a regular expression.
         # callback is something like 'foo.views.news.stories.story_detail',
         # which represents the path to a module and a view function name.
+        self.regex = re.compile(regex)
         self.callback = callback
         self.default_args = default_args or {}
 
-    def search(self, path):
+    def resolve(self, path):
         match = self.regex.search(path)
         if match:
             args = dict(match.groupdict(), **self.default_args)
@@ -43,56 +44,44 @@ class RegexURLPattern:
         except AttributeError, e:
             raise ViewDoesNotExist, "Tried %s in module %s. Error was: %s" % (func_name, mod_name, str(e))
 
-class RegexURLMultiplePattern:
+class RegexURLResolver:
-    def __init__(self, regex, urlconf_module):
+    def __init__(self, regex, urlconf_name):
+        # regex is a string representing a regular expression.
+        # urlconf_name is a string representing the module containing urlconfs.
         self.regex = re.compile(regex)
-        # urlconf_module is a string representing the module containing urlconfs.
+        self.urlconf_name = urlconf_name
-        self.urlconf_module = urlconf_module
 
-    def search(self, path):
+    def resolve(self, path):
         match = self.regex.search(path)
         if match:
             new_path = path[match.end():]
-            try: # Lazily load self.url_patterns.
-                self.url_patterns
-            except AttributeError:
-                self.url_patterns = self.get_url_patterns()
             for pattern in self.url_patterns:
-                sub_match = pattern.search(new_path)
+                sub_match = pattern.resolve(new_path)
                 if sub_match:
                     return sub_match
+            # None of the regexes matched, so raise a 404.
+            raise Http404, "Tried all URL patterns but didn't find a match for %r" % path
 
-    def get_url_patterns(self):
+    def _get_urlconf_module(self):
-        return __import__(self.urlconf_module, '', '', ['']).urlpatterns
+        self.urlconf_module = __import__(self.urlconf_name, '', '', [''])
+        return self.urlconf_module
+    urlconf_module = property(_get_urlconf_module)
 
-class RegexURLResolver:
+    def _get_url_patterns(self):
-    def __init__(self, url_patterns):
+        self.url_patterns = self.urlconf_module.urlpatterns
-        # url_patterns is a list of RegexURLPattern or RegexURLMultiplePattern objects.
+        return self.url_patterns
-        self.url_patterns = url_patterns
+    url_patterns = property(_get_url_patterns)
 
-    def resolve(self, app_path):
+    def _resolve_special(self, view_type):
-        # app_path is the full requested Web path. This is assumed to have a
+        callback = getattr(self.urlconf_module, 'handler%s' % view_type)
-        # leading slash but doesn't necessarily have a trailing slash.
+        mod_name, func_name = get_mod_func(callback)
-        # Examples:
-        #     "/news/2005/may/"
-        #     "/news/"
-        #     "/polls/latest"
-        # A home (root) page is represented by "/".
-        app_path = app_path[1:] # Trim leading slash.
-        for pattern in self.url_patterns:
-            match = pattern.search(app_path)
-            if match:
-                return match
-        # None of the regexes matched, so raise a 404.
-        raise Http404, "Tried all URL patterns but didn't find a match for %r" % app_path
-
-class Error404Resolver:
-    def __init__(self, callback):
-        self.callback = callback
-
-    def resolve(self):
-        mod_name, func_name = get_mod_func(self.callback)
         try:
             return getattr(__import__(mod_name, '', '', ['']), func_name), {}
         except (ImportError, AttributeError), e:
-            raise ViewDoesNotExist, "Tried %s. Error was: %s" % (self.callback, str(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')