TypedEventEmitter
TypedEventEmitter<
Events> =object
A type-safe wrapper around the standard Node.js EventEmitter interface. Root SDK types that emit events include TypedEventEmitter in their type signature, which constrains event names and listener parameters to the associated *Events map at compile time.
Type Parameters
| Type Parameter |
|---|
Events extends EventMap |
Methods
addListener()
addListener<
E>(event:E,listener:Events[E]):TypedEventEmitter<Events>
Type Parameters
| Type Parameter |
|---|
E extends string | number | symbol |
Parameters
| Parameter | Type |
|---|---|
event | E |
listener | Events[E] |
Returns
TypedEventEmitter<Events>
emit()
emit<
E>(event:E, ...args:Parameters<Events[E]>):boolean
Type Parameters
| Type Parameter |
|---|
E extends string | number | symbol |
Parameters
| Parameter | Type |
|---|---|
event | E |
...args | Parameters<Events[E]> |
Returns
boolean
eventNames()
eventNames(): (
string|symbol| keyofEvents)[]
Returns
(string | symbol | keyof Events)[]
getMaxListeners()
getMaxListeners():
number
Returns
number
listenerCount()
listenerCount<
E>(event:E):number
Type Parameters
| Type Parameter |
|---|
E extends string | number | symbol |
Parameters
| Parameter | Type |
|---|---|
event | E |
Returns
number
listeners()
listeners<
E>(event:E):Events[E][]
Type Parameters
| Type Parameter |
|---|
E extends string | number | symbol |
Parameters
| Parameter | Type |
|---|---|
event | E |
Returns
Events[E][]
off()
off<
E>(event:E,listener:Events[E]):TypedEventEmitter<Events>
Remove a previously registered listener.
Type Parameters
| Type Parameter |
|---|
E extends string | number | symbol |
Parameters
| Parameter | Type | Description |
|---|---|---|
event | E | Event name. |
listener | Events[E] | The same callback reference passed to on or once. |
Returns
TypedEventEmitter<Events>
on()
on<
E>(event:E,listener:Events[E]):TypedEventEmitter<Events>
Subscribe to an event. The callback signature is enforced by the Events type parameter.
Type Parameters
| Type Parameter |
|---|
E extends string | number | symbol |
Parameters
| Parameter | Type | Description |
|---|---|---|
event | E | Event name. Must be a key of the associated Events map. |
listener | Events[E] | Callback invoked when the event fires. |
Returns
TypedEventEmitter<Events>
once()
once<
E>(event:E,listener:Events[E]):TypedEventEmitter<Events>
Subscribe to an event for a single firing, then automatically unsubscribe.
Type Parameters
| Type Parameter |
|---|
E extends string | number | symbol |
Parameters
| Parameter | Type | Description |
|---|---|---|
event | E | Event name. |
listener | Events[E] | Callback invoked once. |
Returns
TypedEventEmitter<Events>
prependListener()
prependListener<
E>(event:E,listener:Events[E]):TypedEventEmitter<Events>
Type Parameters
| Type Parameter |
|---|
E extends string | number | symbol |
Parameters
| Parameter | Type |
|---|---|
event | E |
listener | Events[E] |
Returns
TypedEventEmitter<Events>
prependOnceListener()
prependOnceListener<
E>(event:E,listener:Events[E]):TypedEventEmitter<Events>
Type Parameters
| Type Parameter |
|---|
E extends string | number | symbol |
Parameters
| Parameter | Type |
|---|---|
event | E |
listener | Events[E] |
Returns
TypedEventEmitter<Events>
removeAllListeners()
removeAllListeners<
E>(event?:E):TypedEventEmitter<Events>
Type Parameters
| Type Parameter |
|---|
E extends string | number | symbol |
Parameters
| Parameter | Type |
|---|---|
event? | E |
Returns
TypedEventEmitter<Events>
removeListener()
removeListener<
E>(event:E,listener:Events[E]):TypedEventEmitter<Events>
Type Parameters
| Type Parameter |
|---|
E extends string | number | symbol |
Parameters
| Parameter | Type |
|---|---|
event | E |
listener | Events[E] |
Returns
TypedEventEmitter<Events>