Merge pull request #123 from mikeywaites/feature/memoize

Change tracking when marshalling many mappers

Author: jackqu7

VERSION

@@ -1 +1 @@
-1.0.0-rc6
+1.0.0-rc7

kim/mapper.py

@@ -733,6 +733,7 @@ def __init__(self, mapper, **mapper_params):
 
         self.mapper = mapper
         self.mapper_params = mapper_params
+        self._changes = []
 
     def get_mapper(self, data=None, obj=None):
         """return a new instance of the provided mapper.
@@ -776,6 +777,14 @@ def marshal(self, data, role='__default__'):
 
         output = []  # TODO should this be user defined?
         for datum in data:
-            output.append(self.get_mapper(data=datum).marshal(role=role))
+            mapper = self.get_mapper(data=datum)
+            output.append(mapper.marshal(role=role))
+            self._changes.append(mapper.get_changes())
 
         return output
+
+    def get_changes(self):
+        """return the list of changes from each mapper
+        """
+
+        return self._changes

tests/test_mapper.py

@@ -527,6 +527,30 @@ class MapperBase(Mapper):
     assert (res2.name, res2.id) == ('bob', 2)
 
 
+def test_mapper_marshal_many_mapper_changes():
+
+    class MapperBase(Mapper):
+
+        __type__ = TestType
+
+        id = Integer()
+        name = String()
+
+    data = [{'name': 'mike', 'id': 1}, {'name': 'bob', 'id': 2}]
+
+    mapper = MapperBase.many()
+    mapper.marshal(data)
+
+    assert mapper.get_changes() == [
+        {
+            'id': {'old_value': None, 'new_value': 1},
+            'name': {'old_value': None, 'new_value': 'mike'}},
+        {
+            'id': {'old_value': None, 'new_value': 2},
+            'name': {'old_value': None, 'new_value': 'bob'}},
+    ]
+
+
 def test_mapper_marshal_many_with_role():
 
     class MapperBase(Mapper):