Example custom enums

examples/server-enum.py

+'''
+  This example demonstrates the use of custom enums by:
+  - Create a custom enum type
+  - Create an object that contains a variable of this type
+'''
+try:
+    from IPython import embed
+except ImportError:
+    import code
+
+    def embed():
+        vars = globals()
+        vars.update(locals())
+        shell = code.InteractiveConsole(vars)
+        shell.interact()
+
+interactive = True
+
+
+from opcua import ua, Server
+from opcua.common import node
+from enum import IntEnum
+
+# Not required just for convenience
+# Because this example is based on EnumStrings, the values should start at 0 and no gaps are allowed.
+class MyEnum(IntEnum):
+    ok = 0
+    idle = 1
+
+# helper method to automatically create string list
+def enum_to_stringlist(a_enum):
+    items = []
+    for value in a_enum:
+        items.append(ua.LocalizedText(value.name))
+    return items
+
+if __name__ == "__main__":
+    # setup our server
+    server = Server()
+    server.set_endpoint("opc.tcp://0.0.0.0:4840/freeopcua/server/")
+
+    # setup our own namespace, not really necessary but should as spec
+    uri = "http://examples.freeopcua.github.io"
+    nsidx = server.register_namespace(uri)
+
+    # --------------------------------------------------------
+    # create custom enum data type
+    # --------------------------------------------------------
+    enums = server.get_root_node().get_child(["0:Types", "0:DataTypes", "0:BaseDataType", "0:Enumeration"])
+
+    # 1.
+    # Create Enum Type
+    myenum_type = enums.add_subtype(nsidx, 'MyEnum', ua.NodeClass.DataType)
+
+    # 2.
+    # Add enumerations as EnumStrings (Not yet tested with EnumValues)
+    # Essential to use namespace 0 for EnumStrings !
+
+    # By hand
+    #     es = myenum_type.add_variable(0, "EnumStrings" , [ua.LocalizedText("ok"),
+    #                                                       ua.LocalizedText("idle")])
+
+    # Or convert the existing IntEnum MyEnum
+    es = myenum_type.add_variable(0, "EnumStrings" , enum_to_stringlist(MyEnum))
+
+    es.set_value_rank(1)
+    es.set_array_dimensions([0])
+
+    # --------------------------------------------------------
+    # create object with enum variable
+    # --------------------------------------------------------
+    # get Objects node, this is where we should put our custom stuff
+    objects = server.get_objects_node()
+
+    # create object
+    myobj = objects.add_object(nsidx, 'MyObjectWithEnumVar')
+
+    # add var with as type the custom enumeration
+    myenum_var = myobj.add_variable(nsidx, 'MyEnum2Var', MyEnum.ok, myenum_type.nodeid)
+    myenum_var.set_writable()
+    myenum_var.set_value(MyEnum.idle)  # change value of enumeration
+
+    server.start()
+    try:
+        if interactive:
+            embed()
+        else:
+            while True:
+                time.sleep(0.5)
+
+    except IOError:
+        pass
+    finally:
+        server.stop()
+        print("done")