added shortcuts to common nodes

opcua/client/client.py

@@ -13,6 +13,7 @@ from opcua.common.manage_nodes import delete_nodes
 from opcua.common.subscription import Subscription
 from opcua.common import utils
 from opcua.crypto import security_policies
+from opcua.common.shortcuts import Shortcuts
 use_crypto = True
 try:
     from opcua.crypto import uacrypto
@@ -97,6 +98,7 @@ class Client(object):
         self.user_private_key = None
         self._session_counter = 1
         self.keepalive = None
+        self.nodes = Shortcuts(self.uaclient)
 
     def __enter__(self):
         self.connect()

opcua/common/shortcuts.py

+from opcua.ua import ObjectIds
+from opcua import Node
+
+
+class Shortcuts(object):
+    """
+    This object contains Node objects to some commonly used nodes
+    """
+    def __init__(self, server):
+        self.root = Node(server, ObjectIds.RootFolder)
+        self.objects = Node(server, ObjectIds.ObjectsFolder)
+        self.server = Node(server, ObjectIds.Server)
+        self.types = Node(server, ObjectIds.TypesFolder)
+        self.base_object_type = Node(server, ObjectIds.BaseObjectType)
+        self.base_data_type = Node(server, ObjectIds.BaseDataType)

opcua/server/server.py

@@ -21,6 +21,7 @@ from opcua.common.manage_nodes import delete_nodes
 from opcua.client.client import Client
 from opcua.crypto import security_policies
 from opcua.common.event_objects import BaseEvent
+from opcua.common.shortcuts import Shortcuts
 use_crypto = True
 try:
     from opcua.crypto import uacrypto
@@ -66,6 +67,8 @@ class Server(object):
     :vartype default_timeout: InternalServer
     :ivar bserver: binary protocol server
     :vartype bserver: BinaryServer
+    :ivar nodes: shortcuts to common nodes 
+    :vartype nodes: Shortcuts
 
     """
 
@@ -84,6 +87,7 @@ class Server(object):
         self.certificate = None
         self.private_key = None
         self._policies = []
+        self.nodes = Shortcuts(self.iserver.isession)
 
         # setup some expected values
         self.register_namespace(self.application_uri)

tests/tests_common.py

@@ -545,16 +545,13 @@ class CommonTests(object):
 
 
     def test_instantiate_1(self):
-        base_type = self.opc.get_root_node().get_child(["0:Types", "0:ObjectTypes", "0:BaseObjectType"])
-
-        dev_t = base_type.add_object_type(0, "MyDevice")
+        dev_t = self.opc.nodes.base_data_type.add_object_type(0, "MyDevice")
         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")
-        objects = self.opc.get_objects_node()
 
-        mydevice = instantiate(objects, dev_t, bname="2:Device0001")
+        mydevice = instantiate(self.opc.nodes.objects, dev_t, bname="2:Device0001")
 
         self.assertEqual(mydevice.get_type_definition(), dev_t.nodeid)
         obj = mydevice.get_child(["0:controller"])
@@ -565,12 +562,11 @@ class CommonTests(object):
 
 
     def test_variable_with_datatype(self):
-        o = self.opc.get_objects_node()
-        v1 = o.add_variable(3, 'VariableEnumType1', ua.ApplicationType.ClientAndServer, datatype=ua.NodeId(ua.ObjectIds.ApplicationType))
+        v1 = self.opc.nodes.objects.add_variable(3, 'VariableEnumType1', ua.ApplicationType.ClientAndServer, datatype=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, datatype=ua.NodeId(ua.ObjectIds.ApplicationType) )
+        v2 = self.opc.nodes.objects.add_variable(3, 'VariableEnumType2', ua.ApplicationType.ClientAndServer, datatype=ua.NodeId(ua.ObjectIds.ApplicationType) )
         tp2 = v2.get_data_type()
         self.assertEqual( ua.NodeId(ua.ObjectIds.ApplicationType), tp2)