Update the Netconf custom rpc as follows:
1) Create a message/field YANG reference.  This is used to keep the
XML tags in the same order as the fields appear in the YANG schema.
This applies only for custom RPCs (one of Netconf twist)
2) Annotate the proto RPCs with custom annotations which are used
when constructing an XML response

Change-Id: I07a8a3f2a44b7081c78e00dab05734a7c6b0a358
diff --git a/netconf/grpc_client/nc_rpc_mapper.py b/netconf/grpc_client/nc_rpc_mapper.py
index dacfc2b..6267b8f 100644
--- a/netconf/grpc_client/nc_rpc_mapper.py
+++ b/netconf/grpc_client/nc_rpc_mapper.py
@@ -17,6 +17,7 @@
 import sys
 import inspect
 from structlog import get_logger
+from netconf.constants import Constants as C
 
 log = get_logger()
 
@@ -32,6 +33,7 @@
         self.work_dir = work_dir
         self.grpc_client = grpc_client
         self.rpc_map = {}
+        self.yang_defs = {}
 
     def _add_rpc_map(self, func_name, func_ref):
         if not self.rpc_map.has_key(func_name):
@@ -42,6 +44,10 @@
         for name, ref in self.list_functions(mod):
             self._add_rpc_map(name, ref)
 
+    def _add_m(self, mod):
+        for name, ref in self.list_functions(mod):
+            self._add_rpc_map(name, ref)
+
     def is_mod_function(self, mod, func):
         return inspect.isfunction(func) and inspect.getmodule(func) == mod
 
@@ -63,20 +69,88 @@
             except Exception, e:
                 log.exception('loading-module-exception', modname=modname, e=e)
 
+        # load the yang definition
+        for fname in [f for f in os.listdir(self.work_dir)
+                      if f.endswith(C.YANG_MESSAGE_DEFINITIONS_FILE)]:
+            modname = fname[:-len('.py')]
+            try:
+                m = __import__(modname)
+                for name, ref in self.list_functions(m):
+                    self.yang_defs[name] = ref
+            except Exception, e:
+                log.exception('loading-yang-module-exception', modname=modname,
+                              e=e)
+
+    def get_fields_from_yang_defs(self, service, method):
+        # Get the return type of that method
+        func_name = self._get_function_name(service, method)
+        return_type_func_name = ''.join(['get_return_type_', func_name])
+        if self.rpc_map.has_key(return_type_func_name):
+            type_name = self.rpc_map[return_type_func_name]()
+            log.info('get-yang-defs', type_name=type_name, service=service,
+                     method=method)
+            if type_name:
+                # Type name is in the form "<package-name>_pb2".<message_name>
+                name = type_name.split('.')
+                if len(name) == 2:
+                    package = name[0][:-len('_pb2')]
+                    message_name = name[1]
+                    if self.yang_defs.has_key('get_fields'):
+                        return self.yang_defs['get_fields'](package,
+                                                            message_name)
+                else:
+                    log.info('Incorrect-type-format', type_name=type_name,
+                             service=service,
+                             method=method)
+        return None
+
+    def get_fields_from_type_name(self, module_name, type_name):
+        if self.yang_defs.has_key('get_fields'):
+            return self.yang_defs['get_fields'](module_name,
+                                                type_name)
+
     def get_function(self, service, method):
-        if service:
-            func_name = ''.join([service, '_', method])
-        else:
-            func_name = method
+
+        func_name = self._get_function_name(service, method)
 
         if self.rpc_map.has_key(func_name):
             return self.rpc_map[func_name]
         else:
             return None
 
+    def get_xml_tag(self, service, method):
+        func_name = self._get_function_name(service, method)
+        xml_tag_func_name = ''.join(['get_xml_tag_', func_name])
+        if self.rpc_map.has_key(xml_tag_func_name):
+            tag = self.rpc_map[xml_tag_func_name]()
+            if tag == '':
+                return None
+            else:
+                return tag
+        else:
+            return None
+
+    def get_list_items_name(self, service, method):
+        func_name = self._get_function_name(service, method)
+        list_items_name = ''.join(['get_list_items_name_', func_name])
+        if self.rpc_map.has_key(list_items_name):
+            name = self.rpc_map[list_items_name]()
+            if name == '':
+                return None
+            else:
+                return name
+        else:
+            return None
+
     def is_rpc_exist(self, rpc_name):
         return self.rpc_map.has_key(rpc_name)
 
+    def _get_function_name(self, service, method):
+        if service:
+            return ''.join([service, '_', method])
+        else:
+            return method
+
 
 def get_nc_rpc_mapper_instance(work_dir=None, grpc_client=None):
     if NetconfRPCMapper.instance == None: