Adds ability to blind append and prepend to a list

cqlengine/query.py

@@ -681,9 +681,8 @@ class ModelQuerySet(AbstractQuerySet):
             if isinstance(col, Counter):
                 # TODO: implement counter updates
                 raise NotImplementedError
-            elif isinstance(col, BaseContainerColumn):
+            elif isinstance(col, (List, Set)):
                 if isinstance(col, List): klass = ListUpdateClause
-                elif isinstance(col, Map): klass = MapUpdateClause
                 elif isinstance(col, Set): klass = SetUpdateClause
                 else: raise RuntimeError
                 us.add_assignment_clause(klass(

cqlengine/statements.py

@@ -215,8 +215,8 @@ class SetUpdateClause(ContainerUpdateClause):
 class ListUpdateClause(ContainerUpdateClause):
     """ updates a list collection """
 
-    def __init__(self, field, value, previous=None, column=None):
-        super(ListUpdateClause, self).__init__(field, value, previous, column=column)
+    def __init__(self, field, value, operation=None, previous=None, column=None):
+        super(ListUpdateClause, self).__init__(field, value, operation, previous, column=column)
         self._append = None
         self._prepend = None
 
@@ -261,6 +261,14 @@ class ListUpdateClause(ContainerUpdateClause):
         if self.value is None or self.value == self.previous:
             pass
 
+        elif self._operation == "append":
+            self._append = self.value
+
+        elif self._operation == "prepend":
+            # self.value is a Quoter but we reverse self._prepend later as if
+            # it's a list, so we have to set it to the underlying list
+            self._prepend = self.value.value
+
         elif self.previous is None:
             self._assignments = self.value
 
@@ -269,7 +277,6 @@ class ListUpdateClause(ContainerUpdateClause):
             # rewrite the whole list
             self._assignments = self.value
 
-
         elif len(self.previous) == 0:
             # if we're updating from an empty
             # list, do a complete insert

cqlengine/tests/query/test_updates.py

@@ -14,6 +14,7 @@ class TestQueryUpdateModel(Model):
     count       = columns.Integer(required=False)
     text        = columns.Text(required=False, index=True)
     text_set    = columns.Set(columns.Text, required=False)
+    text_list   = columns.List(columns.Text, required=False)
 
 class QueryUpdateTests(BaseCassEngTestCase):
 
@@ -159,3 +160,25 @@ class QueryUpdateTests(BaseCassEngTestCase):
                 text_set__remove={'afsd'})
         obj = TestQueryUpdateModel.objects.get(partition=partition, cluster=cluster)
         self.assertEqual(obj.text_set, {"foo"})
+
+    def test_list_append_updates(self):
+        partition = uuid4()
+        cluster = 1
+        TestQueryUpdateModel.objects.create(
+                partition=partition, cluster=cluster, text_list=["foo"])
+        TestQueryUpdateModel.objects(
+                partition=partition, cluster=cluster).update(
+                text_list__append=['bar'])
+        obj = TestQueryUpdateModel.objects.get(partition=partition, cluster=cluster)
+        self.assertEqual(obj.text_list, ["foo", "bar"])
+
+    def test_list_prepend_updates(self):
+        partition = uuid4()
+        cluster = 1
+        TestQueryUpdateModel.objects.create(
+                partition=partition, cluster=cluster, text_list=["foo"])
+        TestQueryUpdateModel.objects(
+                partition=partition, cluster=cluster).update(
+                text_list__prepend=['bar'])
+        obj = TestQueryUpdateModel.objects.get(partition=partition, cluster=cluster)
+        self.assertEqual(obj.text_list, ["bar", "foo"])