Variable update within server method

[IevgenVovk]

Hello,
assuming the server-minimal.py example, how may one update the variable value from within the func() call?

Schematically (omitting non-essential parts of server-minimal.py):

...
@uamethod
def func(parent, value):
    return value * 2              # <-- Want to set MyVariable =  2*value


async def main():
...
    # populating our address space
    # server.nodes, contains links to very common nodes like objects and root
    myobj = await server.nodes.objects.add_object(idx, "MyObject")
    myvar = await myobj.add_variable(idx, "MyVariable", 6.7)      # <-- Want to change this from func()
    # Set MyVariable to be writable by clients
    await myvar.set_writable()
    await server.nodes.objects.add_method(
        ua.NodeId("ServerMethod", idx),
        ua.QualifiedName("ServerMethod", idx),
        func,
        [ua.VariantType.Int64],
        [ua.VariantType.Int64],
    )
 ...

[schroeder-]

You can use a class for example:

class MultiplyMethodCallHandler:
    def __init__(self, target) -> None:
        self._target = target

    @uamethod
    async def call(self, parent, y, x):
        print(self._target)
        await self._target.write_value(ua.Double(x * y))
        print(x * y)
        return x * y

.....

async def main():
    .....    
    mydouble = await myobj.add_variable(idx, "MyDouble", 0.0)
    callh = MultiplyMethodCallHandler(mydouble)
    multiply_node = await myobj.add_method(
        idx,
        "multiply",
        callh.call,
        [ua.VariantType.Double, ua.VariantType.Double],
        [ua.VariantType.Double],
    )

The other possiblity is to use inner functions, but in this case this not a good idea. Because they can get messy in larger applications.

[IevgenVovk]

Wonderful solution, thanks a lot!