OptionalactionThe action that drove the transition, or undefined if none did.
OptionalforcedWhether this transition came from force_transition rather than transition.
OptionalfromThe state being left.
OptionaltoThe state being entered.
Optionaltrans_Which arrow kind the traversed edge carries — legal, main, or forced.
Populated only when a transition-kind hook is installed (a standard,
main, or forced transition hook, or their post- equivalents). With no such
hook registered there is nothing to switch on, so jssm skips resolving the
edge's kind and this is undefined. Install hook_standard_transition
(or a sibling) if a general handler needs to read it.
Context object passed to every HookHandler.
datais the data payload as it stands before the transition, andnext_datais the payload that will be committed if the transition is accepted — handlers may inspect or mutate the latter via a HookComplexResult return value.The remaining fields describe the transition the hook is firing on. They are optional because a handler is not obliged to care about them, but the transition path always supplies all of them;
actionisundefinedwhen the transition was not driven by an action.