1 files changed, 67 insertions, 0 deletions
diff --git a/azure/aria/aria-extension-cloudify/src/aria/aria/parser/presentation/null.py b/azure/aria/aria-extension-cloudify/src/aria/aria/parser/presentation/null.py
new file mode 100644
index 0000000..287d2ba
--- /dev/null
+++ b/azure/aria/aria-extension-cloudify/src/aria/aria/parser/presentation/null.py
@@ -0,0 +1,67 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from ...utils.collections import deepcopy_with_locators
+
+
+class Null(object):
+    """
+    Represents an explicit null value provided by the user, which is different from
+    not supplying a value at all.
+
+    It is a singleton.
+    """
+
+    @property
+    def as_raw(self):
+        return None
+
+NULL = Null()
+
+
+def none_to_null(value):
+    """
+    Convert ``None`` to ``NULL``, recursively.
+    """
+
+    if value is None:
+        return NULL
+    if isinstance(value, list):
+        value = deepcopy_with_locators(value)
+        for i, _ in enumerate(value):
+            value[i] = none_to_null(value[i])
+    elif isinstance(value, dict):
+        value = deepcopy_with_locators(value)
+        for k, v in value.iteritems():
+            value[k] = none_to_null(v)
+    return value
+
+
+def null_to_none(value):
+    """
+    Convert ``NULL`` to ``None``, recursively.
+    """
+
+    if value is NULL:
+        return None
+    if isinstance(value, list):
+        value = deepcopy_with_locators(value)
+        for i, _ in enumerate(value):
+            value[i] = none_to_null(value[i])
+    elif isinstance(value, dict):
+        value = deepcopy_with_locators(value)
+        for k, v in value.iteritems():
+            value[k] = none_to_null(v)
+    return value