Added a simple server that import an xml file and a client that calls the methods defines

examples/simple-client-server-xml/client_minimal.py

+from opcua import Client, ua
+from opcua.ua import ua_binary as uabin
+from opcua.common.methods import call_method
+
+
+class HelloClient:
+    def __init__(self, endpoint):
+        self.client = Client(endpoint)
+
+    def __enter__(self):
+        self.client.connect()
+        return self.client
+
+    def __exit__(self, exc_type, exc_val, exc_tb):
+        self.client.disconnect()
+
+
+if __name__ == '__main__':
+    with HelloClient("opc.tcp://localhost:40840/freeopcua/server/") as client:
+        root = client.get_root_node()
+        print("Root node is: ", root)
+        objects = client.get_objects_node()
+        print("Objects node is: ", objects)
+
+        hellower = objects.get_child("0:Hellower")
+        print("Hellower is: ", hellower)
+
+        resulting_text = hellower.call_method("0:SayHello", False)
+        print(resulting_text)
+
+        resulting_text = hellower.call_method("1:SayHello2", True)
+        print(resulting_text)
+
+        resulting_array = hellower.call_method("1:SayHelloArray", False)
+        print(resulting_array)

examples/simple-client-server-xml/server.py

+import os.path
+try:
+    from IPython import embed
+except ImportError:
+    import code
+
+    def embed():
+        vars = globals()
+        vars.update(locals())
+        shell = code.InteractiveConsole(vars)
+        shell.interact()
+
+from opcua import ua, uamethod, Server
+
+
+@uamethod
+def say_hello_xml(parent, happy):
+    print("Calling say_hello_xml")
+    if happy:
+        result = "I'm happy"
+    else:
+        result = "I'm not happy"
+    print(result)
+    return result
+
+
+@uamethod
+def say_hello(parent, happy):
+    if happy:
+        result = "I'm happy"
+    else:
+        result = "I'm not happy"
+    print(result)
+    return result
+
+
+@uamethod
+def say_hello_array(parent, happy):
+    if happy:
+        result = "I'm happy"
+    else:
+        result = "I'm not happy"
+    print(result)
+    return [result, "Actually I am"]
+
+
+class HelloServer:
+    def __init__(self, endpoint, name, model_filepath):
+        self.server = Server()
+
+        #  This need to be imported at the start or else it will overwrite the data
+        self.server.import_xml(model_filepath)
+
+        self.server.set_endpoint(endpoint)
+        self.server.set_server_name(name)
+
+        objects = self.server.get_objects_node()
+
+        freeopcua_namespace = self.server.get_namespace_index("urn:freeopcua:python:server")
+        hellower = objects.get_child("0:Hellower")
+        hellower_say_hello = hellower.get_child("0:SayHello")
+
+        self.server.link_method(hellower_say_hello, say_hello_xml)
+
+        hellower.add_method(
+            freeopcua_namespace, "SayHello2", say_hello, [ua.VariantType.Boolean], [ua.VariantType.String])
+
+        hellower.add_method(
+            freeopcua_namespace, "SayHelloArray", say_hello_array, [ua.VariantType.Boolean], [ua.VariantType.String])
+
+    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 HelloServer(
+            "opc.tcp://0.0.0.0:40840/freeopcua/server/",
+            "FreeOpcUa Example Server",
+            os.path.join(script_dir, "test_saying.xml")) as server:
+        embed()

examples/simple-client-server-xml/test_saying.xml

+<?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="HasProperty">i=46</Alias>
+    <Alias Alias="HasComponent">i=47</Alias>
+    <Alias Alias="Argument">i=296</Alias>
+  </Aliases>
+  <NamespaceUris />
+  <UAObject BrowseName="0:Hellower" NodeId="i=20001" ParentNodeId="i=85">
+    <DisplayName>BaseObjectType</DisplayName>
+    <Description>The base type for all object nodes.</Description>
+    <References>
+      <Reference IsForward="false" ReferenceType="Organizes">i=85</Reference>
+      <Reference ReferenceType="HasTypeDefinition">i=58</Reference>
+      <Reference ReferenceType="HasComponent">i=20002</Reference>
+    </References>
+  </UAObject>
+  <UAMethod BrowseName="0:SayHello" NodeId="i=20002" ParentNodeId="i=20001">
+    <DisplayName>SayHello</DisplayName>
+    <Description>SayHello</Description>
+    <References>
+      <Reference IsForward="false" ReferenceType="HasComponent">i=20001</Reference>
+      <Reference ReferenceType="HasProperty">i=20003</Reference>
+      <Reference ReferenceType="HasProperty">i=20004</Reference>
+    </References>
+  </UAMethod>
+  <UAVariable BrowseName="0:InputArguments" DataType="Argument" NodeId="i=20003" ParentNodeId="i=20002" 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:ValueRank>-1</uax:ValueRank>
+              <uax:Description>
+                <uax:Text />
+                <uax:Locale />
+              </uax:Description>
+              <uax:DataType>
+                <uax:Identifier>i=1</uax:Identifier>
+              </uax:DataType>
+              <uax:Name>happy</uax:Name>
+              <uax:ArrayDimensions />
+            </uax:Argument>
+          </uax:Body>
+        </uax:ExtensionObject>
+      </uax:ListOfExtensionObject>
+    </Value>
+    <References>
+      <Reference IsForward="false" ReferenceType="HasProperty">i=20002</Reference>
+      <Reference ReferenceType="HasTypeDefinition">i=68</Reference>
+    </References>
+  </UAVariable>
+  <UAVariable BrowseName="0:OutputArguments" DataType="Argument" NodeId="i=20004" ParentNodeId="i=20002" 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:ValueRank>-1</uax:ValueRank>
+              <uax:Description>
+                <uax:Text />
+                <uax:Locale />
+              </uax:Description>
+              <uax:DataType>
+                <uax:Identifier>i=12</uax:Identifier>
+              </uax:DataType>
+              <uax:Name>saying</uax:Name>
+              <uax:ArrayDimensions />
+            </uax:Argument>
+          </uax:Body>
+        </uax:ExtensionObject>
+      </uax:ListOfExtensionObject>
+    </Value>
+    <References>
+      <Reference IsForward="false" ReferenceType="HasProperty">i=20002</Reference>
+      <Reference ReferenceType="HasTypeDefinition">i=68</Reference>
+    </References>
+  </UAVariable>
+</UANodeSet>