Ticket #11981: 11981.q_filter_exclude.diff

django/db/models/query.py

@@ -508 +508 @@
         if args or kwargs:
             assert self.query.can_filter(), \
                     "Cannot filter a query once a slice has been taken."
-
+        if not kwargs and len(args) == 1 and hasattr(args[0], 'add_to_query'):
+            q = args[0]
+        else:
+            q = Q(*args, **kwargs)
+        if negate:
+            q = ~q
         clone = self._clone()
-        if negate:
-            clone.query.add_q(~Q(*args, **kwargs))
-        else:
-            clone.query.add_q(Q(*args, **kwargs))
+        clone.query.add_q(q)
         return clone
 
     def complex_filter(self, filter_obj):

tests/modeltests/or_lookups/models.py

@@ -25 +25 @@
 
     def __unicode__(self):
         return self.headline
+        
+class HeadlineContainsQ(object):
+    def __init__(self, substr, negated=False):
+        self.substr = substr
+        self.negated = negated
 
+    def add_to_query(self, query, aliases=None):
+        q = models.Q(headline__icontains=self.substr)
+        if self.negated:
+            q = ~q
+        query.add_q(q)
+        
+    def __invert__(self):
+        return self.__class__(self.substr, not self.negated)
+
 __test__ = {'API_TESTS':"""
 >>> from datetime import datetime
 >>> from django.db.models import Q
@@ -133 +147 @@
 [<Article: Hello>]
 >>> Article.objects.complex_filter(Q(pk=1) | Q(pk=2))
 [<Article: Hello>, <Article: Goodbye>]
+
+>>> Article.objects.filter(HeadlineContainsQ("good"))
+[<Article: Goodbye>, <Article: Hello and goodbye>]
+>>> Article.objects.exclude(HeadlineContainsQ("good"))
+[<Article: Hello>]
 """}