How to start and await for a state machine's asynchronous execution?

[mpenna]

I have this scenario where the state machine will be frequently triggered/started by an external process (e.g.: a cron-like task manager), which will need to block until whatever asynchronous processing the state machine has been configured to execute finishes. Is this achievable? State would be serialized/persisted and pulled/hydrated back upon every triggered execution. However, I'm not sure how the blocking of the external (controller) process would be handled.

Thanks.

[matthewp]

Your finish is "finished" when it hits a final state, a state which has no transitions. What I would probably do is something like this:

let resolve;
let promise = new Promise(_resolve => {
  resolve = _resolve;
})

service = interpret(machine, () => {
  if(machine.state.value.final) {
    resolve();
  }
});

await promise;
// All done!

[mpenna]

Nice! Let me try that strategy out and see how it goes.

Thanks!

[ehuelsmann]

@mpenna did the strategy work? If so, can we close this issue?

[mpenna]

It's been a long time since I last looked and touched the project where I was using this, but if my memory serves me well, yes, I believe it did work.

Thanks and sorry for replying sooner.

[ehuelsmann]

@matthewp I propose to close this issue based on the response above.

[ehuelsmann]

@matthewp , I think it'd make sense add a guide or section with "recommended patterns".

[matthewp]

@ehuelsmann yeah we can close this. And yeah, we have that with our guides: https://thisrobot.life/guides.html which explains a couple of patterns like this. So could add some docs there.

[ehuelsmann]

I'll issue a PR adding a micro-guide. Then we'll be able to close this issue with that PR.