Add datatype to create_variable (#235)

* Add datatype to create_variable

* Add datatype to create_variable, code cleanup

opcua/common/manage_nodes.py

@@ -80,12 +80,15 @@ def create_property(parent, *args):
 def create_variable(parent, *args):
     """
     create a child node variable
-    args are nodeid, browsename, value, [variant type]
-    or idx, name, value, [variant type]
+    args are nodeid, browsename, value, [variant type], [data type]
+    or idx, name, value, [variant type], [data type] 
     """
     nodeid, qname = _parse_add_args(*args[:2])
-    val = _to_variant(*args[2:])
-    return node.Node(parent.server, _create_variable(parent.server, parent.nodeid, nodeid, qname, val, isproperty=False))
+    val, datatype = _to_variant_with_datatype(*args[2:])
+    if  datatype and not isinstance(datatype, ua.NodeId):
+        raise RuntimeError()
+    
+    return node.Node(parent.server, _create_variable(parent.server, parent.nodeid, nodeid, qname, val, datatype, isproperty=False))
 
 
 def create_method(parent, *args):
@@ -156,13 +159,17 @@ def _create_object(server, parentnodeid, nodeid, qname, objecttype):
 
 
 def _to_variant(val, vtype=None):
+    return _to_variant_with_datatype(val, vtype, datatype=None )[0]
+
+def _to_variant_with_datatype(val, vtype=None, datatype=None):
     if isinstance(val, ua.Variant):
-        return val
+        if vtype:
+            datatype = vtype
+        return val, datatype
     else:
-        return ua.Variant(val, vtype)
-
+        return ua.Variant(val, vtype), datatype  
 
-def _create_variable(server, parentnodeid, nodeid, qname, val, isproperty=False):
+def _create_variable(server, parentnodeid, nodeid, qname, val, datatype=None, isproperty=False):
     addnode = ua.AddNodesItem()
     addnode.RequestedNewNodeId = nodeid
     addnode.BrowseName = qname
@@ -177,7 +184,11 @@ def _create_variable(server, parentnodeid, nodeid, qname, val, isproperty=False)
     attrs = ua.VariableAttributes()
     attrs.Description = ua.LocalizedText(qname.Name)
     attrs.DisplayName = ua.LocalizedText(qname.Name)
-    attrs.DataType = _guess_uatype(val)
+    if datatype:
+        attrs.DataType = datatype
+    else:
+        attrs.DataType = _guess_uatype(val)
+        
     attrs.Value = val
     if isinstance(val, list) or isinstance(val, tuple):
         attrs.ValueRank = ua.ValueRank.OneDimension

tests/tests_server.py

@@ -325,6 +325,16 @@ class TestServer(unittest.TestCase, CommonTests, SubscriptionTests):
         self.assertEqual(evgen.event.PropertyNum, None)
         self.assertEqual(evgen.event.PropertyString, None)
 
+    def test_add_variable_with_datatype(self):
+        o = self.opc.get_objects_node()
+        v1 = o.add_variable(3, 'VariableEnumType1', ua.ApplicationType.ClientAndServer, None, ua.NodeId(ua.ObjectIds.ApplicationType))
+        tp1 = v1.get_data_type()
+        self.assertEqual( ua.NodeId(ua.ObjectIds.ApplicationType), tp1)
+        
+        v2 = o.add_variable(3, 'VariableEnumType2', ua.ApplicationType.ClientAndServer, None, ua.NodeId(ua.ObjectIds.ApplicationType) )
+        tp2 = v2.get_data_type()
+        self.assertEqual( ua.NodeId(ua.ObjectIds.ApplicationType), tp2)         
+
 
 def check_eventgenerator_SourceServer(test, evgen):
     server = test.opc.get_server_node()