Improve instantiate when parent has string node id + small fixes (#342)

* Improve instantiate when parent has string node id

* Make String node id instantiation more clear

* Fix string to value for boolean

Can't use bool(string); will always return true
Make string to UA ints more readable

* Ignore XML Extensions tag

Other modelers make this XML element which contains a model and hash
from the generation tool

* Add test for instaniate with String NodeIds

* Handle import of Null values

opcua/common/instantiate.py

@@ -13,7 +13,7 @@ def instantiate(parent, node_type, nodeid=None, bname=None, idx=0):
     """
     instantiate a node type under a parent node.
     nodeid and browse name of new node can be specified, or just namespace index
-    If they exists children of the node type, such as components, variables and 
+    If they exists children of the node type, such as components, variables and
     properties are also instantiated
     """
     rdesc = _rdesc_from_node(parent, node_type)
@@ -23,7 +23,7 @@ def instantiate(parent, node_type, nodeid=None, bname=None, idx=0):
     if bname is None:
         bname = rdesc.BrowseName
     elif isinstance(bname, str):
-        bname = ua.QualifiedName.from_string(bname)    
+        bname = ua.QualifiedName.from_string(bname)
 
     nodeids = _instantiate_node(parent.server, parent.nodeid, rdesc, nodeid, bname)
     return [Node(parent.server, nid) for nid in nodeids]
@@ -53,7 +53,7 @@ def _instantiate_node(server, parentid, rdesc, nodeid, bname, recursive=True):
 
     elif rdesc.NodeClass in (ua.NodeClass.Variable, ua.NodeClass.VariableType):
         addnode.NodeClass = ua.NodeClass.Variable
-        _read_and_copy_attrs(node_type, ua.VariableAttributes(), addnode)            
+        _read_and_copy_attrs(node_type, ua.VariableAttributes(), addnode)
     elif rdesc.NodeClass in (ua.NodeClass.Method,):
         addnode.NodeClass = ua.NodeClass.Method
         _read_and_copy_attrs(node_type, ua.MethodAttributes(), addnode)
@@ -63,7 +63,7 @@ def _instantiate_node(server, parentid, rdesc, nodeid, bname, recursive=True):
 
     res = server.add_nodes([addnode])[0]
     added_nodes = [res.AddedNodeId]
-    
+
     if recursive:
         parents = ua_utils.get_node_supertypes(node_type, includeitself=True)
         node = Node(server, res.AddedNodeId)
@@ -71,10 +71,15 @@ def _instantiate_node(server, parentid, rdesc, nodeid, bname, recursive=True):
             descs = parent.get_children_descriptions(includesubtypes=False)
             for c_rdesc in descs:
                 # skip items that already exists, prefer the 'lowest' one in object hierarchy
-                if not ua_utils.is_child_present(node, c_rdesc.BrowseName):                    
-                    nodeids = _instantiate_node(server, res.AddedNodeId, c_rdesc, nodeid=ua.NodeId(namespaceidx=res.AddedNodeId.NamespaceIndex), bname=c_rdesc.BrowseName)
+                if not ua_utils.is_child_present(node, c_rdesc.BrowseName):
+                    # if root node being instantiated has a String NodeId, create the children with a String NodeId
+                    if res.AddedNodeId.NodeIdType is ua.NodeIdType.String:
+                        inst_nodeid = res.AddedNodeId.Identifier + "." + c_rdesc.BrowseName.Name
+                        nodeids = _instantiate_node(server, res.AddedNodeId, c_rdesc, nodeid=ua.NodeId(identifier=inst_nodeid, namespaceidx=res.AddedNodeId.NamespaceIndex), bname=c_rdesc.BrowseName)
+                    else:
+                        nodeids = _instantiate_node(server, res.AddedNodeId, c_rdesc, nodeid=ua.NodeId(namespaceidx=res.AddedNodeId.NamespaceIndex), bname=c_rdesc.BrowseName)
                     added_nodes.extend(nodeids)
-                
+
     return added_nodes
 
 

opcua/common/ua_utils.py

@@ -74,8 +74,13 @@ def string_to_val(string, vtype):
     if vtype == ua.VariantType.Null:
         val = None
     elif vtype == ua.VariantType.Boolean:
-        val = bool(string)
-    elif 4 <= vtype.value < 9:
+        if string in ("True", "true", "on", "On", "1"):
+            val = True
+        else:
+            val = False
+    elif vtype in (ua.VariantType.Int16, ua.VariantType.Int32, ua.VariantType.Int64):
+            val = int(string)
+    elif vtype in (ua.VariantType.UInt16, ua.VariantType.UInt32, ua.VariantType.UInt64):
         val = int(string)
     elif vtype in (ua.VariantType.Float, ua.VariantType.Double):
         val = float(string)

opcua/common/xmlparser.py

@@ -136,7 +136,7 @@ class XMLParser(object):
         nodes = []
         for child in self.root:
             tag = self._retag.match(child.tag).groups()[1]
-            if tag not in ["Aliases", "NamespaceUris"]:
+            if tag not in ["Aliases", "NamespaceUris", "Extensions"]:  # these XML tags don't contain nodes
                 node = self._parse_node(tag, child)
                 nodes.append(node)
         return nodes
@@ -208,7 +208,10 @@ class XMLParser(object):
 
     def _parse_value(self, val_el, obj):
         child_el = val_el.find(".//")  # should be only one child
-        ntag = self._retag.match(child_el.tag).groups()[1]
+        if child_el is not None:
+            ntag = self._retag.match(child_el.tag).groups()[1]
+        else:
+            ntag = "Null"
         obj.valuetype = ntag
 
         if ntag in ("Int8", "UInt8", "Int16", "UInt16", "Int32", "UInt32", "Int64", "UInt64"):
@@ -242,6 +245,8 @@ class XMLParser(object):
             obj.value = self._parse_list(child_el)
         elif ntag == "ExtensionObject":
             obj.value = self._parse_ext_obj(child_el)
+        elif ntag == "Null":
+            obj.value = None
         else:
             self.logger.warning("Parsing value of type '%s' not implemented", ntag)
 

tests/tests_common.py

@@ -607,8 +607,29 @@ class CommonTests(object):
         prop1 = mydevicederived.get_child(["0:sensorx_id"])
         var1 = mydevicederived.get_child(["0:childparam"])
         var_parent = mydevicederived.get_child(["0:sensor"])
-        prop_parent = mydevicederived.get_child(["0:sensor_id"])        
+        prop_parent = mydevicederived.get_child(["0:sensor_id"])
 
+    def test_instantiate_string_nodeid(self):
+        # Create device type
+        dev_t = self.opc.nodes.base_object_type.add_object_type(0, "MyDevice2")
+        v_t = dev_t.add_variable(0, "sensor", 1.0)
+        p_t = dev_t.add_property(0, "sensor_id", "0340")
+        ctrl_t = dev_t.add_object(0, "controller")
+        prop_t = ctrl_t.add_property(0, "state", "Running")
+
+        # instanciate device
+        nodes = instantiate(self.opc.nodes.objects, dev_t, nodeid=ua.NodeId("InstDevice", 2, ua.NodeIdType.String), bname="2:InstDevice")
+        mydevice = nodes[0]
+
+        self.assertEqual(mydevice.get_node_class(), ua.NodeClass.Object)
+        self.assertEqual(mydevice.get_type_definition(), dev_t.nodeid)
+        obj = mydevice.get_child(["0:controller"])
+        obj_nodeid_ident = obj.nodeid.Identifier
+        prop = mydevice.get_child(["0:controller", "0:state"])
+        self.assertEqual(obj_nodeid_ident, "InstDevice.controller")
+        self.assertEqual(prop.get_type_definition().Identifier, ua.ObjectIds.PropertyType)
+        self.assertEqual(prop.get_value(), "Running")
+        self.assertNotEqual(prop.nodeid, prop_t.nodeid)
 
     def test_variable_with_datatype(self):
         v1 = self.opc.nodes.objects.add_variable(3, 'VariableEnumType1', ua.ApplicationType.ClientAndServer, datatype=ua.NodeId(ua.ObjectIds.ApplicationType))