# HG changeset patch
# User Ludovic Chabant <ludovic@chabant.com>
# Date 1409554098 25200
# Node ID d64e4703f5e6be26eafdef16d93fd9de158d177d
# Parent  838a9dd0e23cb5ef153ac43f5863af2937d6c3fa
Propertly create `OrderedDict`s when loading YAML.

diff -r 838a9dd0e23c -r d64e4703f5e6 piecrust/configuration.py
--- a/piecrust/configuration.py	Sat Aug 30 18:30:50 2014 -0700
+++ b/piecrust/configuration.py	Sun Aug 31 23:48:18 2014 -0700
@@ -127,6 +127,20 @@
 class OrderedDictYAMLLoader(yaml.SafeLoader):
     """ A YAML loader that loads mappings into ordered dictionaries.
     """
+    def __init__(self, *args, **kwargs):
+        super(OrderedDictYAMLLoader, self).__init__(*args, **kwargs)
+
+        self.add_constructor(u'tag:yaml.org,2002:map',
+                type(self).construct_yaml_map)
+        self.add_constructor(u'tag:yaml.org,2002:omap',
+                type(self).construct_yaml_map)
+
+    def construct_yaml_map(self, node):
+        data = collections.OrderedDict()
+        yield data
+        value = self.construct_mapping(node)
+        data.update(value)
+
     def construct_mapping(self, node, deep=False):
         if not isinstance(node, yaml.MappingNode):
             raise ConstructorError(None, None,