Ticket #8221: improved_exceptions_for_reverse.diff

django/core/urlresolvers.py

@@ -51 +51 @@
             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)
+                lookup_view = getattr(__import__(mod_name,{}, {}, ['']), func_name)
+                if not callable(lookup_view):
+                    raise AttributeError("'%s' in module '%s' is not a callable."
+                            % (func_name, mod_name))
         except (ImportError, AttributeError):
             if not can_fail:
                 raise
@@ -197 +200 @@
         try:
             lookup_view = getattr(__import__(mod_name, {}, {}, ['']), func_name)
         except (ImportError, AttributeError):
-            raise NoReverseMatch
+            raise NoReverseMatch("Error importing '%s': %s." % (viewname, e))
         if lookup_view != self.callback:
-            raise NoReverseMatch
+            raise NoReverseMatch("Imported '%s' doesn't match the expected function." % viewname)
         return self.reverse_helper(*args, **kwargs)
 
     def reverse_helper(self, *args, **kwargs):
@@ -284 +287 @@
     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)
+        except (ImportError, AttributeError), e:
+            raise NoReverseMatch("Error importing '%s': %s." % (lookup_view, e))
         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)