Add convenice function to get a copy of the labthings logger

[julianstirling]

Is your feature request related to a problem? Please describe.

Action code often starts up code that happens in utility functions that don't have access to the ThingLogger, as self.logger in the same way an Action does.

Describe the solution you'd like

Add a convenience method such as lt.get_action_logger() to get an instance of the correct logger.

Describe alternatives you've considered

Workarounds include:

• Passing the thing logger
• Using getLogger with the correct log name

[rwb27]

Am I correct in thinking, after our conversation today, that you're no longer convinced this is useful? I've not included it in #393 on those grounds.

This is already possible, FWIW, by importing THING_LOGGER from labthings_fastapi.logs. It doesn't have any leading underscores but it's not officially part of the public API.

I'll suggest @julianstirling closes this one to confirm he's happy it's no longer needed.

[julianstirling]

We said we didn't was "USER" level, but we do want access to the ThingLogger as this would be how we get data into the UI

[rwb27]

Thinking about this some more, I'm wondering if exposing the thing logger is the neatest solution here. I've no issue exposing it and will try to make a PR that does so.

It would be fairly straightforward to attach a handler that collects log records for the invocations to arbitrary loggers. I think that has the significant advantage that the code external to the Thing can use whatever logger it wants and doesn't gain a dependency on LabThings.

I realise the immediate issue for OFM doesn't care about adding the dependency, but I think there will be plenty situations where it's desirable to avoid it, in the interests of keeping things loosely coupled.

[julianstirling]

In this case how do we identify whether the log is showing up in the action log field. If we capture everything from arbitrary loggers, then we are back to the situation where we can't log without causing UI noise. We could add a LabThings specific argument to logging, but then this still means that downstream code needs to to something labthings specific

[rwb27]

My thinking was that we could expose a function that allows actions to add other loggers to the invocation logs for the duration of that invocation. I think we'd also want to ensure that the logger name is included in the invocation log for distinguishability. It also eliminates the potential for confusing name clashes between children of the Thing logger used by non-Thing code, and Things with the same name, though that's definitely an edge case.

What I'm suggesting would look like:

import labthings_fastapi as lt
import external_library.module


class MyThing(lt.Thing):
    @lt.action
    def do_stuff(self):
        lt.capture_to_invocation_log("external_library.module")
        external_library.module.functionality()

That avoids the need for any LabThings-specific code in the external module, which I think is nice, but it's for another day. I think it will be useful in some situations, but ought not to cause too much unwanted noise.