allow to read DataValue from node. change a bit get_attribute method, fix a test for pypy

opcua/node.py

@@ -129,43 +129,50 @@ class Node(object):
         composed of a string(name) and a namespace index.
         """
         result = self.get_attribute(ua.AttributeIds.BrowseName)
-        return result.Value
+        return result.Value.Value
 
     def get_display_name(self):
         """
         get description attribute of node
         """
         result = self.get_attribute(ua.AttributeIds.DisplayName)
-        return result.Value
+        return result.Value.Value
 
     def get_data_type(self):
         """
         get data type of node
         """
         result = self.get_attribute(ua.AttributeIds.DataType)
-        return result.Value
+        return result.Value.Value
 
     def get_node_class(self):
         """
         get node class attribute of node
         """
         result = self.get_attribute(ua.AttributeIds.NodeClass)
-        return result.Value
+        return result.Value.Value
 
     def get_description(self):
         """
         get description attribute class of node
         """
         result = self.get_attribute(ua.AttributeIds.Description)
-        return result.Value
+        return result.Value.Value
 
     def get_value(self):
         """
-        Get value of a node. Only variables(properties) have values.
+        Get value of a node as a python type. Only variables(properties) have values.
         An exception will be generated for other node types.
         """
-        result = self.get_attribute(ua.AttributeIds.Value)
-        return result.Value
+        result = self.get_data_value()
+        return result.Value.Value
+
+    def get_data_value(self):
+        """
+        Get value of a node as a python type. Only variables(properties) have values.
+        An exception will be generated for other node types.
+        """
+        return self.get_attribute(ua.AttributeIds.Value)
 
     def set_value(self, value, varianttype=None):
         """
@@ -186,6 +193,8 @@ class Node(object):
             datavalue = ua.DataValue(ua.Variant(value, varianttype))
         self.set_attribute(ua.AttributeIds.Value, datavalue)
 
+    set_data_value = set_value
+
     def set_attribute(self, attributeid, datavalue):
         """
         Set an attribute of a node
@@ -201,7 +210,7 @@ class Node(object):
 
     def get_attribute(self, attr):
         """
-        Get an attribute of a node
+        Read one attribute of a node
         """
         rv = ua.ReadValueId()
         rv.NodeId = self.nodeid
@@ -210,7 +219,7 @@ class Node(object):
         params.NodesToRead.append(rv)
         result = self.server.read(params)
         result[0].StatusCode.check()
-        return result[0].Value
+        return result[0]
 
     def get_children(self, refs=ua.ObjectIds.HierarchicalReferences, nodeclassmask=ua.NodeClass.Unspecified):
         """

opcua/uatypes.py

@@ -50,10 +50,9 @@ def datetime_to_win_epoch(dt):
 def win_epoch_to_datetime(epch):
     (s, ns100) = divmod(epch - EPOCH_AS_FILETIME, HUNDREDS_OF_NANOSECONDS)
     try:
-        # TDA, this generates exceptions on systems where RTC is really off
         dt = datetime.utcfromtimestamp(s)
-    except:
-        logger.debug("Exception occurred during conversion within 'win_epoch_to_datetime'.")
+    except Exception as ex: #FIXME: find out what kind of exceptin is raised!!!
+        logger.debug("Exception occurred during conversion within 'win_epoch_to_datetime'. %s", ex)
         return datetime.now()
     dt = dt.replace(microsecond=(ns100 // 10))
     return dt
@@ -850,12 +849,18 @@ class DataValue(FrozenClass):
         return obj
 
     def __str__(self):
-        return 'DataValue(' + 'Encoding:' + str(self.Encoding) + ', ' + \
-            'Value:' + str(self.Value) + ', ' + \
-            'StatusCode:' + str(self.StatusCode) + ', '  + \
-            'SourceTimestamp:' + str(self.SourceTimestamp) + ', ' + \
-            'ServerTimestamp:' + str(self.ServerTimestamp) + ', ' + \
-            'SourcePicoseconds:' + str(self.SourcePicoseconds) + ', ' + \
-            'ServerPicoseconds:' + str(self.ServerPicoseconds) + ')'
+        s = 'DataValue(Value:{})'.format(self.Value)
+        if self.StatusCode is not None:
+            s += ', StatusCode:{}'.format(self.StatusCode)
+        if self.SourceTimestamp is not None:
+            s += ', SourceTimestamp:{}'.format(self.SourceTimestamp)
+        if self.ServerTimestamp is not None:
+            s += ', ServerTimestamp:{}'.format(self.ServerTimestamp)
+        if self.SourcePicoseconds is not None:
+            s += ', SourcePicoseconds:{}'.format(self.SourcePicoseconds)
+        if self.ServerPicoseconds is not None:
+            s += ', ServerPicoseconds:{}'.format(self.ServerPicoseconds)
+        s += ')'
+        return s
 
     __repr__ = __str__

setup.py

@@ -3,7 +3,7 @@ from distutils.command.install_data import install_data
 
 
 setup (name = "freeopcua", 
-        version = "0.9.3",
+        version = "0.9.6",
         description = "Pure Python OPC-UA client and server library",
         author = "Olivier Roulet-Dubonnet",
         author_email = "olivier.roulet@gmail.com",

tests.py

@@ -456,6 +456,34 @@ class CommonTests(object):
         with self.assertRaises(Exception):
             bad.get_child(0, "myobj")
 
+    def test_value(self):
+        o = self.opc.get_objects_node()
+        var = ua.Variant(1.98, ua.VariantType.Double)
+        v = o.add_variable(3, 'VariableValue', var)
+        val = v.get_value()
+        self.assertEqual(1.98, val)
+
+        dvar = ua.DataValue(var)
+        dv = v.get_data_value()
+        self.assertEqual(ua.DataValue, type(dv))
+        self.assertEqual(dvar.Value, dv.Value)
+        self.assertEqual(dvar.Value, var)
+
+    def test_set_value(self):
+        o = self.opc.get_objects_node()
+        var = ua.Variant(1.98, ua.VariantType.Double)
+        dvar = ua.DataValue(var)
+        v = o.add_variable(3, 'VariableValue', var)
+        v.set_value(var.Value)
+        v1 = v.get_value()
+        self.assertEqual(v1, var.Value)
+        v.set_value(var)
+        v2 = v.get_value()
+        self.assertEqual(v2, var.Value)
+        v.set_data_value(dvar)
+        v3 = v.get_data_value()
+        self.assertEqual(v3.Value, dvar.Value)
+
     def test_array_value(self):
         o = self.opc.get_objects_node()
         v = o.add_variable(3, 'VariableArrayValue', [1, 2, 3])
@@ -528,7 +556,7 @@ class CommonTests(object):
         clthandle, node, val, attr = msclt.future.result()
         self.assertEqual(node, server_time_node)
         delta = datetime.now() - val
-        self.assertTrue(delta < timedelta(seconds=1))
+        self.assertTrue(delta < timedelta(seconds=2))
 
         sub.unsubscribe(handle)
         sub.delete()