Fixed "$pull" semantics for nested ListFields (#447)

mongoengine/common.py

@@ -23,8 +23,9 @@ def _import_class(cls_name):
     field_classes = ('DictField', 'DynamicField', 'EmbeddedDocumentField',
                      'FileField', 'GenericReferenceField',
                      'GenericEmbeddedDocumentField', 'GeoPointField',
-                     'PointField', 'LineStringField', 'PolygonField',
-                     'ReferenceField', 'StringField', 'ComplexBaseField')
+                     'PointField', 'LineStringField', 'ListField',
+                     'PolygonField', 'ReferenceField', 'StringField',
+                     'ComplexBaseField')
     queryset_classes = ('OperationError',)
     deref_classes = ('DeReference',)
 

mongoengine/fields.py

@@ -780,6 +780,10 @@ class DictField(ComplexBaseField):
 
         if op in match_operators and isinstance(value, basestring):
             return StringField().prepare_query_value(op, value)
+
+        if hasattr(self.field, 'field'):
+            return self.field.prepare_query_value(op, value)
+
         return super(DictField, self).prepare_query_value(op, value)
 
 

mongoengine/queryset/transform.py

@@ -182,6 +182,7 @@ def update(_doc_cls=None, **update):
             parts = []
 
             cleaned_fields = []
+            appended_sub_field = False
             for field in fields:
                 append_field = True
                 if isinstance(field, basestring):
@@ -193,10 +194,17 @@ def update(_doc_cls=None, **update):
                 else:
                     parts.append(field.db_field)
                 if append_field:
+                    appended_sub_field = False
                     cleaned_fields.append(field)
+                    if hasattr(field, 'field'):
+                        cleaned_fields.append(field.field)
+                        appended_sub_field = True
 
             # Convert value to proper value
-            field = cleaned_fields[-1]
+            if appended_sub_field:
+                field = cleaned_fields[-2]
+            else:
+                field = cleaned_fields[-1]
 
             if op in (None, 'set', 'push', 'pull'):
                 if field.required or value is not None:
@@ -223,11 +231,24 @@ def update(_doc_cls=None, **update):
 
         if 'pull' in op and '.' in key:
             # Dot operators don't work on pull operations
-            # it uses nested dict syntax
+            # unless they point to a list field
+            # Otherwise it uses nested dict syntax
             if op == 'pullAll':
                 raise InvalidQueryError("pullAll operations only support "
                                         "a single field depth")
 
+            # Look for the last list field and use dot notation until there
+            field_classes = [c.__class__ for c in cleaned_fields]
+            field_classes.reverse()
+            ListField = _import_class('ListField')
+            if ListField in field_classes:
+                # Join all fields via dot notation to the last ListField
+                # Then process as normal
+                last_listField = len(cleaned_fields) - field_classes.index(ListField)
+                key = ".".join(parts[:last_listField])
+                parts = parts[last_listField:]
+                parts.insert(0, key)
+
             parts.reverse()
             for key in parts:
                 value = {key: value}