Four tests passing now. Recursively parsing the search nodes and negated on NOT as required.

tests/xapian_tests/tests/xapian_query.py

@@ -61,10 +61,10 @@ class XapianSearchQueryTestCase(TestCase):
         self.sq.add_filter(SQ(content='world'))
         self.assertEqual(self.sq.build_query().get_description(), 'Xapian::Query((hello AND world))')
     
-    # def test_build_query_multiple_words_not(self):
-    #     self.sq.add_filter(~SQ(content='hello'))
-    #     self.sq.add_filter(~SQ(content='world'))
-    #     self.assertEqual(self.sq.build_query().get_description(), 'Xapian::Query((NOT hello NOT world))')
+    def test_build_query_multiple_words_not(self):
+        self.sq.add_filter(~SQ(content='hello'))
+        self.sq.add_filter(~SQ(content='world'))
+        self.assertEqual(self.sq.build_query().get_description(), 'Xapian::Query(((<alldocuments> AND_NOT hello) AND (<alldocuments> AND_NOT world)))')
     
     # def test_build_query_multiple_words_or(self):
     #     self.sq.add_filter('content', 'hello', use_or=True)

xapian_backend.py

@@ -15,7 +15,7 @@
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
 __author__ = 'David Sauve'
-__version__ = (1, 0, 0, 'beta')
+__version__ = (2, 0, 0, 'alpha')
 
 import datetime
 import cPickle as pickle
@@ -29,7 +29,7 @@ from django.conf import settings
 from django.core.exceptions import ImproperlyConfigured
 from django.utils.encoding import smart_unicode, force_unicode
 
-from haystack.backends import BaseSearchBackend, BaseSearchQuery, log_query
+from haystack.backends import BaseSearchBackend, BaseSearchQuery, SearchNode, log_query
 from haystack.exceptions import MissingDependency
 from haystack.fields import DateField, DateTimeField, IntegerField, FloatField, BooleanField, MultiValueField
 from haystack.models import SearchResult
@@ -936,19 +936,32 @@ class SearchQuery(BaseSearchQuery):
     
     def build_query(self):
         if not self.query_filter:
-            query = xapian.Query('')
+            return xapian.Query('')
         else:
-            query_list = []
-            
-            for child in self.query_filter.children:
-                expression, value = child
-                query_list.append(value)
-                
-            query = xapian.Query(xapian.Query.OP_AND, query_list)
-        
-        return query
+            return self._query_from_search_node(self.query_filter)
 
-    def build_query_fragment(self, field, filter_type, value):
+    def _query_from_search_node(self, search_node, is_not=False):
+        query_list = []
+        
+        for child in search_node.children:
+            if isinstance(child, SearchNode):
+                query_list.append(
+                    xapian.Query(
+                        xapian.Query.OP_AND, 
+                        self._query_from_search_node(child, child.negated)
+                    )
+                )
+            else:
+                expression, value = child
+                if is_not:
+                    # DS_TODO: This can almost definitely be improved.
+                    query_list.append(xapian.Query(xapian.Query.OP_AND_NOT, '', value))
+                else:
+                    query_list.append(xapian.Query(value))
+                
+        return xapian.Query(xapian.Query.OP_AND, query_list)
+
+    def build_sub_query(self, value):
         return xapian.Query(value)
 
         #