Custom type methods with examples

examples/complex-type-client-server/client.py

@@ -0,0 +1,44 @@
+from opcua import Client
+from common import KeyValuePair
+
+
+class HelloClient(object):
+    def __init__(self, endpoint):
+        self._client = Client(endpoint)
+
+        # We cannot set them properly as we are still not connected to the server
+        self._root = None
+        self._objects = None
+        self._hellower = None
+
+    def __enter__(self):
+        # __enter__ and __exit__ are called when getting the object with the with keyword. See context manager
+        # documentation for more information
+        self._client.connect()
+
+        # As soon as we are connected to the server, we set the variables
+        self._root = self._client.get_root_node()
+        self._objects = self._client.get_objects_node()
+        self._hellower = self._objects.get_child("0:Hellower")
+        return self
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self._client.disconnect()
+
+    def say_hello(self, complex_variable, complex_variable_list):
+        """Adapt the method call so it is used like a normal python method"""
+        return self._hellower.call_method(
+            "0:SayComplexHello",
+            complex_variable,
+            complex_variable_list
+        )
+
+
+if __name__ == '__main__':
+    with HelloClient("opc.tcp://localhost:40840/freeopcua/server/") as hello_client:
+        complex_error, complex_error_list = hello_client.say_hello(
+                KeyValuePair("foo", "bar"),
+                [KeyValuePair("toto", "tata"), KeyValuePair("Hello", "World")],
+            )
+
+        print(complex_error, complex_error_list)

examples/complex-type-client-server/common.py

@@ -0,0 +1,75 @@
+from opcua.common.methods import to_variant
+from opcua.ua import ua_binary as uabin
+from opcua.ua.uatypes import Variant
+from opcua.common.ua_utils import register_extension_object
+
+
+class KeyValuePair(object):
+    # The DEFAULT_BINARY is the NodeId of the custom type
+    DEFAULT_BINARY = 20001
+
+    def __init__(self, key, value, namespace_id=0):
+        self.key = key
+        self.value = value
+        self.NamespaceIndex = namespace_id
+
+    def __repr__(self):
+        return "KeyValuePair(key={}, value={})".format(self.key, self.value)
+
+    def to_binary(self):
+        # We need to define to_binary. It will be used when serializing the object
+        packet = []
+        packet.append(uabin.Primitives.UInt16.pack(self.NamespaceIndex))
+        packet.append(uabin.Primitives.String.pack(self.key))
+        packet.append(uabin.Primitives.String.pack(self.value))
+        return b''.join(packet)
+
+    @staticmethod
+    def from_binary(data):
+        # This is how we deserialize the object
+        namespace_index = uabin.Primitives.UInt16.unpack(data)
+        key = uabin.Primitives.String.unpack(data)
+        value = uabin.Primitives.String.unpack(data)
+        return KeyValuePair(key, value, namespace_index)
+
+
+class ErrorKeyValue(object):
+    DEFAULT_BINARY = 20002
+
+    def __init__(self, code, description, extensions, namespace_id=0):
+        self.code = code
+        self.description = description
+        self.extensions = extensions
+        self.NamespaceIndex = namespace_id
+
+    def __repr__(self):
+        return "ErrorKeyValue(code='{}', description='{}', extensions={})".format(
+            self.code, self.description, self.extensions)
+
+    def to_binary(self):
+        packet = []
+        packet.append(uabin.Primitives.UInt16.pack(self.NamespaceIndex))
+        packet.append(uabin.Primitives.String.pack(self.code))
+        packet.append(uabin.Primitives.String.pack(self.description))
+
+        # When we want to serialize a list, we need to transform the objects to a Variant and then manually call
+        # to_binary() to serialize them
+        for i in to_variant(self.extensions):
+            packet.append(i.to_binary())
+
+        return b''.join(packet)
+
+    @staticmethod
+    def from_binary(data):
+        namespace_index = uabin.Primitives.UInt16.unpack(data)
+        code = uabin.Primitives.String.unpack(data)
+        description = uabin.Primitives.String.unpack(data)
+
+        # When descerialising, you'll get a Variant object back. This is how get the object's value back
+        extensions = Variant.from_binary(data)
+        extensions = [ext for ext in extensions.Value]
+        return ErrorKeyValue(code, description, extensions, namespace_index)
+
+# For each custom type defined, we need to register it so the script know how to serialize / deserialise them
+register_extension_object(KeyValuePair)
+register_extension_object(ErrorKeyValue)

examples/complex-type-client-server/nodeset.xml

@@ -0,0 +1,151 @@
+<?xml version='1.0' encoding='utf-8'?>
+<UANodeSet xmlns="http://opcfoundation.org/UA/2011/03/UANodeSet.xsd" xmlns:uax="http://opcfoundation.org/UA/2008/02/Types.xsd" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+  <Aliases>
+    <Alias Alias="Organizes">i=35</Alias>
+    <Alias Alias="HasTypeDefinition">i=40</Alias>
+    <Alias Alias="HasSubtype">i=45</Alias>
+    <Alias Alias="HasProperty">i=46</Alias>
+    <Alias Alias="HasComponent">i=47</Alias>
+    <Alias Alias="Argument">i=296</Alias>
+  </Aliases>
+  <NamespaceUris />
+  <UADataType BrowseName="0:KeyValue" NodeId="i=20001">
+    <DisplayName>KeyValue</DisplayName>
+    <Description>KeyValue</Description>
+    <References>
+      <Reference IsForward="false" ReferenceType="HasSubtype">i=22</Reference>
+    </References>
+  </UADataType>
+  <UADataType BrowseName="0:ErrorKeyValue" NodeId="i=20002">
+    <DisplayName>ErrorKeyValue</DisplayName>
+    <Description>ErrorKeyValue</Description>
+    <References>
+      <Reference IsForward="false" ReferenceType="HasSubtype">i=22</Reference>
+    </References>
+  </UADataType>
+  <UAObjectType BrowseName="0:HellowerType" NodeId="i=20004">
+    <DisplayName>HellowerType</DisplayName>
+    <Description>HellowerType</Description>
+    <References>
+      <Reference IsForward="false" ReferenceType="HasSubtype">i=58</Reference>
+    </References>
+  </UAObjectType>
+  <UAObject BrowseName="0:Hellower" NodeId="i=20005" ParentNodeId="i=85">
+    <DisplayName>HellowerType</DisplayName>
+    <Description>HellowerType</Description>
+    <References>
+      <Reference IsForward="false" ReferenceType="Organizes">i=85</Reference>
+      <Reference ReferenceType="HasTypeDefinition">i=20004</Reference>
+      <Reference ReferenceType="HasComponent">i=20006</Reference>
+    </References>
+  </UAObject>
+  <UAMethod BrowseName="0:SayComplexHello" NodeId="i=20006" ParentNodeId="i=20005">
+    <DisplayName>SayComplexHello</DisplayName>
+    <Description>SayComplexHello</Description>
+    <References>
+      <Reference IsForward="false" ReferenceType="HasComponent">i=20005</Reference>
+      <Reference ReferenceType="HasProperty">i=20007</Reference>
+      <Reference ReferenceType="HasProperty">i=20008</Reference>
+    </References>
+  </UAMethod>
+  <UAVariable BrowseName="0:InputArguments" DataType="Argument" NodeId="i=20007" ParentNodeId="i=20006" ValueRank="0">
+    <DisplayName>InputArguments</DisplayName>
+    <Description>InputArguments</Description>
+    <Value>
+      <uax:ListOfExtensionObject>
+        <uax:ExtensionObject>
+          <uax:TypeId>
+            <uax:Identifier>i=296</uax:Identifier>
+          </uax:TypeId>
+          <uax:Body>
+            <uax:Argument>
+              <uax:Description>
+                <uax:Locale />
+                <uax:Text />
+              </uax:Description>
+              <uax:ArrayDimensions />
+              <uax:DataType>
+                <uax:Identifier>i=20001</uax:Identifier>
+              </uax:DataType>
+              <uax:ValueRank>-1</uax:ValueRank>
+              <uax:Name>complex_variable</uax:Name>
+            </uax:Argument>
+          </uax:Body>
+        </uax:ExtensionObject>
+        <uax:ExtensionObject>
+          <uax:TypeId>
+            <uax:Identifier>i=296</uax:Identifier>
+          </uax:TypeId>
+          <uax:Body>
+            <uax:Argument>
+              <uax:Description>
+                <uax:Locale />
+                <uax:Text />
+              </uax:Description>
+              <uax:ArrayDimensions />
+              <uax:DataType>
+                <uax:Identifier>i=20001</uax:Identifier>
+              </uax:DataType>
+              <uax:ValueRank>-1</uax:ValueRank>
+              <uax:Name>complex_variable_list</uax:Name>
+            </uax:Argument>
+          </uax:Body>
+        </uax:ExtensionObject>
+      </uax:ListOfExtensionObject>
+    </Value>
+    <References>
+      <Reference IsForward="false" ReferenceType="HasProperty">i=20006</Reference>
+      <Reference ReferenceType="HasTypeDefinition">i=68</Reference>
+    </References>
+  </UAVariable>
+  <UAVariable BrowseName="0:OutputArguments" DataType="Argument" NodeId="i=20008" ParentNodeId="i=20006" ValueRank="0">
+    <DisplayName>OutputArguments</DisplayName>
+    <Description>OutputArguments</Description>
+    <Value>
+      <uax:ListOfExtensionObject>
+        <uax:ExtensionObject>
+          <uax:TypeId>
+            <uax:Identifier>i=296</uax:Identifier>
+          </uax:TypeId>
+          <uax:Body>
+            <uax:Argument>
+              <uax:Description>
+                <uax:Locale />
+                <uax:Text />
+              </uax:Description>
+              <uax:ArrayDimensions />
+              <uax:DataType>
+                <uax:Identifier>i=20002</uax:Identifier>
+              </uax:DataType>
+              <uax:ValueRank>-1</uax:ValueRank>
+              <uax:Name>complex_error</uax:Name>
+            </uax:Argument>
+          </uax:Body>
+        </uax:ExtensionObject>
+        <uax:ExtensionObject>
+          <uax:TypeId>
+            <uax:Identifier>i=296</uax:Identifier>
+          </uax:TypeId>
+          <uax:Body>
+            <uax:Argument>
+              <uax:Description>
+                <uax:Locale />
+                <uax:Text />
+              </uax:Description>
+              <uax:ArrayDimensions />
+              <uax:DataType>
+                <uax:Identifier>i=20002</uax:Identifier>
+              </uax:DataType>
+              <uax:ValueRank>-1</uax:ValueRank>
+              <uax:Name>complex_error_list</uax:Name>
+            </uax:Argument>
+          </uax:Body>
+        </uax:ExtensionObject>
+      </uax:ListOfExtensionObject>
+    </Value>
+    <References>
+      <Reference IsForward="false" ReferenceType="HasProperty">i=20006</Reference>
+      <Reference ReferenceType="HasTypeDefinition">i=68</Reference>
+    </References>
+  </UAVariable>
+</UANodeSet>

examples/complex-type-client-server/server.py

@@ -0,0 +1,58 @@
+import os
+from common import KeyValuePair, ErrorKeyValue
+from opcua import uamethod, Server
+try:
+    from IPython import embed
+except ImportError:
+    import code
+
+    def embed():
+        vars = globals()
+        vars.update(locals())
+        shell = code.InteractiveConsole(vars)
+        shell.interact()
+
+
+@uamethod
+def say_complex_hello(parent, complex_variable, complex_variable_list):
+    # The uamethod decorator will take care of converting the data for us. We only work with python objects inside it
+    # For it to work, you need to register your DataType like in common.py
+    print("say_complex_hello called: {}, {}".format(complex_variable, complex_variable_list))
+    complex_error = ErrorKeyValue("0", "foo", [KeyValuePair("key", "value"), KeyValuePair("hello", "world")])
+    complex_error_list = ErrorKeyValue("1", "bar", [KeyValuePair("key", "value")])
+
+    return complex_error, complex_error_list
+
+
+class HellowerServer(object):
+    def __init__(self, endpoint, name, model_filepath):
+        self.server = Server()
+
+        self.server.import_xml(model_filepath)
+
+        # Those need to be done after importing the xml file or it will be overwritten
+        self.server.set_endpoint(endpoint)
+        self.server.set_server_name(name)
+
+        objects = self.server.get_objects_node()
+        hellower = objects.get_child("0:Hellower")
+
+        say_hello_node = hellower.get_child("0:SayComplexHello")
+
+        self.server.link_method(say_hello_node, say_complex_hello)
+
+    def __enter__(self):
+        self.server.start()
+        return self.server
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.server.stop()
+
+
+if __name__ == '__main__':
+    script_dir = os.path.dirname(__file__)
+    with HellowerServer(
+            "opc.tcp://0.0.0.0:40840/freeopcua/server/",
+            "FreeOpcUa Example Server",
+            os.path.join(script_dir, "nodeset.xml")) as server:
+        embed()

opcua/common/methods.py

@@ -60,7 +60,8 @@ def wrapper(parent, *args):
             parent = args[0]
             args = args[1:]
             result = func(self, parent, *[arg.Value for arg in args])
-
+        if isinstance(result, (list, tuple)):
+            return to_variant(*result)
         return to_variant(result)
     return wrapper
 
@@ -70,5 +71,3 @@ def to_variant(*args):
     for arg in args:
         uaargs.append(ua.Variant(arg))
     return uaargs
-
-

opcua/common/ua_utils.py

@@ -9,6 +9,8 @@
 
 from opcua import ua
 from opcua.ua.uaerrors import UaError
+from opcua.ua import ObjectIds, ObjectIdNames
+from opcua.ua.uaprotocol_auto import ExtensionClasses
 
 
 def val_to_string(val):
@@ -256,3 +258,9 @@ def get_nodes_of_namespace(server, namespaces=[]):
     nodes = [server.get_node(nodeid) for nodeid in server.iserver.aspace.keys()
              if nodeid.NamespaceIndex != 0 and nodeid.NamespaceIndex in namespace_indexes]
     return nodes
+
+
+def register_extension_object(object_factory):
+    setattr(ObjectIds, "{}_Encoding_DefaultBinary".format(object_factory.__name__), object_factory.DEFAULT_BINARY)
+    ObjectIdNames[object_factory.DEFAULT_BINARY] = object_factory.__name__
+    ExtensionClasses[object_factory.DEFAULT_BINARY] = object_factory

opcua/ua/uatypes.py

@@ -1083,5 +1083,3 @@ def get_default_value(vtype):
         return Variant()
     else:
         raise RuntimeError("function take a uatype as argument, got:", vtype)
-
-