String Address instead of Node Index

[alecmedina-code]

I was wondering, what would be the correct way to create a hierarchical structure where variable addresses would result in a string address like nsu=1;s=MyFolder/MyVariable instead of something like nsu=1;i=1.

I am new to building OPC servers with asyncua. In this instance it would be easier for me to work with string addresses on the client side rather than node ids.

The relevant portion of my current code is below:

 # Import Settings
	settings_file = open('/etc/opcua/monitoring/drives/settings.yaml')
	settings_data = yaml.load(settings_file, Loader=SafeLoader)

	# Define Server
	host = str(settings_data['host'])
	port = str(settings_data.get('port',4840))
	url = "opc.tcp://"+host+":"+port
	server = Server()
	await server.init()
	server.set_endpoint(url)
	print("Starting server at: "+url)

	# Define Namespace
	name_space = await server.register_namespace("1")

	# Define Root Folder
	root = await server.nodes.objects.add_folder(name_space,"Remote Servers")

	# Define Namespace Objects & Variables
	remote_hosts = settings_data['remote_hosts']
	for name, obj in remote_hosts.items():
		# Define Namespace Object
		name_obj = await root.add_folder(name_space, name)
		
		# Define Variables
		variables = []
		drives = obj['drives']
		for drive in drives:
			variable_name = drive.split('/')[-1] + " status"
			variable = await name_obj.add_variable(name_space, variable_name, False)
			print(await variable.read_browse_name())
			await variable.set_writable()
			variables.append(variable)
		remote_hosts[name]['variables'] = variables

[alecmedina-code]

Nevermind, I figured it out. I needed to remove the namespace and specify the string address. Stupid me.

# Import Settings
	settings_file = open('/etc/opcua/monitoring/drives/settings.yaml')
	settings_data = yaml.load(settings_file, Loader=SafeLoader)

	# Define Server
	host = str(settings_data['host'])
	port = str(settings_data.get('port',4840))
	url = "opc.tcp://"+host+":"+port
	server = Server()
	await server.init()
	server.set_endpoint(url)
	print("Starting server at: "+url)

	# Define Root Folder
	root = await server.nodes.objects.add_folder(0,"Remote Servers")

	# Define Namespace Objects & Variables
	remote_hosts = settings_data['remote_hosts']
	for name, obj in remote_hosts.items():
		# Define Namespace Object
		name_obj = await root.add_folder(0, name)
		
		# Define Variables
		variables = []
		drives = obj['drives']
		for drive in drives:
			variable_name = drive.split('/')[-1] + "-status"
			variable_address = "ns=0;s="+"/"+name+"/"+variable_name
			variable = await name_obj.add_variable(ua.NodeId.from_string(variable_address), variable_name, False)
			await variable.set_writable()
			variables.append(variable)
		remote_hosts[name]['variables'] = variables

[schroeder-]

you can also do this:
ua.NodeId('MyFolder/MyVariable', 1)
Also keep in mind you are not supposed to use namespace index 0. This namespace is reserved.

[alecmedina-code]

should it be 1?

[schroeder-]

Register your own namespace and use this index:

 uri = "http://examples.freeopcua.github.io"
 idx = await server.register_namespace(uri)
 ua.NodeId('...', idx)