Creates a Signal grouped by a key. Essentially splits the producer and consumer of a Subject for each key.

export function createKeyedSignal<A extends unknown[], T>(
keySelector?: (signal: T) => K,
mapper?: (...args: A) => T,
): [(key: K) => GroupedObservable<K, T>, (...args: A) => void]


  • keySelector?: (Optional) A function that extracts the key from the emitted value. If omitted, it will use the first argument as the key.

  • mapper?: (Optional) A function for mapping the arguments of the emitter function into the value of the Observable.

    Defaults to (v: Payload) => v


[1, 2]:

  1. A function that returns the observable for a given key

  2. The emitter function

See also