How to resume last state (history nodes)

Question

I'm learning x-state and I'm overwhelmed about its functionality, but I'm having issues understanding history nodes.

I'm creating a state which should hold the execution of the machine until an action is triggered:

So if the machine is in AwaitingEmployeeSignature or AwaitingOnboardingCompletion, and the EA_REDLINED event is triggered, I want to move the machine to the Paused state. But after a RESUME event (which is not implemented), I want to resume the last state AwaitingEmployeeSignature or AwaitingOnboardingCompletion, depending on what was the state before the Paused state

As I understand history nodes, it can achieve what I want, but as far as I understood, it doesn't hold this state, but when on it, it automatically moves to the last state (which is not what I want). How can I stay in the Paused state, and only move to the previous state when the RESUME event is triggered?

Thanks in advance!

score 1 · Answer 1 · answered Apr 12 '22 at 11:22

1

A history node targets the most recently visited child state of a parent state before exiting that parent state.

In your case, the solution would be to place the top 5 states in your diagram in some parent state, add a history state to that parent state, and on resume, transition to that e.g. parent.hist state.

Then the target of that resume event will be the last state that the parent state was in.

answered Apr 12 '22 at 11:22

David Khourshid

4,918
1
11
10

1

Thanks a lot, I'll try this implementation. I'm really impressed with x-state, we are using it as a POC in a big tech company. If all goes well, we plan to use it as the new standard :) – Otavio Bonder Apr 12 '22 at 17:46
@OtavioBonder did all went well? – Cristi Minica Nov 04 '22 at 13:07
I adopted another strategy, improving the transitions – Otavio Bonder Nov 06 '22 at 23:20

How to resume last state (history nodes)

1 Answers1