Emitting Events

Emit statements appear in state notes and register emitters on the EventAdapter. When the FSM enters that state, the emitter runs and pushes events onto the EventBus.

Syntax

emit/<EVENT_NAME>
emit/<EVENT_NAME> (<META_KEY_LIST>)
emit/<EVENT_NAME> (<META_KEY_LIST>) <= #{<CONTEXT_KEY_LIST>}

Part	Description
EVENT_NAME	Globally unique event identifier (see Events)
META_KEY_LIST	Keys to include in emitted event's meta object
<= #{<CONTEXT_KEY_LIST>}	Maps FSM context fields to meta keys (by position)

Meta keys use $key prefix for named slots; #key prefix reads context directly (same name).

Examples

note right of Authorized
  emit/sessionStarted
  emit/sessionStarted (#token)
  emit/sessionStarted ($tok) <= #{authToken}
  emit/sessionStarted ($tok, $exp='never') <= #{authToken}
end note

Form	Emitted meta	Source
bare	{}	-
#key reference	{ token: context.token }	context, same key name
$key <= #{ctx} mapping	{ tok: context.authToken }	context field remapped
with literal default	{ tok: context.authToken, exp: 'never' }	context + fallback literal

Flow

Note: Emit fires on state enter, not on action dispatch. Only emitters for the new state run.

See Events and Event Model.