whenEventType

whenEventType<E, K>(type: K, fn: EntryListener<E & { type: K; }>): (ev: E) => void

Defined in: factory-machine-hooks.ts:183

Creates an entry listener that triggers when the event’s type matches the given event type.

Type Parameters

Type Parameter	Description
E extends FactoryMachineEvent<any>	FactoryMachineEvent type
K extends string	Event type

Parameters

Parameter	Type	Description
type	K	The event type to match
fn	EntryListener<E & { type: K; }>	EntryListener to invoke when matched

Returns

An entry listener for the specified event type

(ev: E): void

Parameters

Parameter	Type
ev	E

Returns

void

Example

setup(machine)(
  whenEventType("activate", handleActivate),
);

Source

Useful for running logic when a specific event type is triggered in a state machine.

export const whenEventType = <
  E extends FactoryMachineEvent<any>,
  K extends E["type"],
>(
  type: K,
  fn: EntryListener<E & { type: K }>
) => when<E>((ev) => ev.type === type, fn as any);