Order props in the spec the same as the API

Use an OrderedDict when reading the api docs so that properties defined in the
API are rendered in the same order in the spec.

templating/matrix_templates/units.py

@@ -21,6 +21,7 @@ For the actual conversion of data -> RST (including templates), see the sections
 file instead.
 """
 from batesian.units import Units
+from collections import OrderedDict
 import logging
 import inspect
 import json
@@ -48,6 +49,20 @@ STATE_EVENT = "core-event-schema/state_event.yaml"
 
 logger = logging.getLogger(__name__)
 
+# a yaml Loader which loads mappings into OrderedDicts instead of regular
+# dicts, so that we preserve the ordering of properties from the api files.
+#
+# with thanks to http://stackoverflow.com/a/21912744/637864
+class OrderedLoader(yaml.Loader):
+    pass
+def construct_mapping(loader, node):
+    loader.flatten_mapping(node)
+    pairs = loader.construct_pairs(node)
+    return OrderedDict(pairs)
+OrderedLoader.add_constructor(
+    yaml.resolver.BaseResolver.DEFAULT_MAPPING_TAG,
+    construct_mapping)
+
 def resolve_references(path, schema):
     if isinstance(schema, dict):
         # do $ref first
@@ -55,11 +70,11 @@ def resolve_references(path, schema):
             value = schema['$ref']
             path = os.path.join(os.path.dirname(path), value)
             with open(path) as f:
-                ref = yaml.load(f)
+                ref = yaml.load(f, OrderedLoader)
             result = resolve_references(path, ref)
             del schema['$ref']
         else:
-            result = {}
+            result = OrderedDict()
 
         for key, value in schema.items():
             result[key] = resolve_references(path, value)
@@ -194,12 +209,9 @@ def process_prop(key_name, prop, required):
 
     value_type = None
     desc = prop.get("description", "")
-    prop_type = prop.get('type')
+    prop_type = prop['type']
     tables = []
 
-    if prop_type is None:
-        raise KeyError("Property '%s' of object '%s' missing 'type' field"
-                       % (key_name, obj))
     logger.debug("%s is a %s", key_name, prop_type)
 
     if prop_type == "object":
@@ -381,6 +393,7 @@ def get_example_for_param(param):
     return json.dumps(get_example_for_schema(param['schema']),
                       indent=2)
 
+
 class MatrixUnits(Units):
     def _load_swagger_meta(self, api, group_name):
         endpoints = []
@@ -563,7 +576,7 @@ class MatrixUnits(Units):
                     # strip .yaml
                     group_name = filename[:-5].replace("-", "_")
                     group_name = "%s_%s" % (group_name, suffix)
-                    api = yaml.load(f.read())
+                    api = yaml.load(f.read(), OrderedLoader)
                     api = resolve_references(filepath, api)
                     api["__meta"] = self._load_swagger_meta(
                         api, group_name
@@ -584,7 +597,7 @@ class MatrixUnits(Units):
                 filepath = os.path.join(root, filename)
                 with open(filepath) as f:
                     try:
-                        event_info = yaml.load(f)
+                        event_info = yaml.load(f, OrderedLoader)
                     except Exception as e:
                         raise ValueError(
                             "Error reading file %r" % (filepath,), e
@@ -677,7 +690,7 @@ class MatrixUnits(Units):
         logger.info("Reading %s" % filepath)
 
         with open(filepath, "r") as f:
-            json_schema = yaml.load(f)
+            json_schema = yaml.load(f, OrderedLoader)
 
         schema = {
             "typeof": "",