Class ObservableTransformer<V, I, U>

constructor

• new ObservableTransformer<V, I, U>(inputs, transformer, decider?): ObservableTransformer<V, I, U>

• Type Parameters

  • V
  • I extends Iterable<Observable<U>, any, any> | [Observable<U>]
  • U = unknown

  Parameters

  • inputs: I

    The list of observables to use as inputs for this transformer.
  • transformer: ((inputs: I) => V)

    The actual transformer function. Takes in a list of input observables, and outputs a single value.

    • • (inputs): V

      • Parameters

        • inputs: I

        Returns V

  • Optionaldecider: ((inputs: I) => boolean)

    Decides whether the transformer's output value needs to be updated or not. If undefined (the default), then the value is always assumed to need to be updated whenever an input watcher is invoked.

    • • (inputs): boolean

      • Parameters

        • inputs: I

        Returns boolean

  Returns ObservableTransformer<V, I, U>

Optional Readonlydecider

Readonlyinputs

Readonlytransformer

value

• get value(): V

• The current value.

  Evaluated when needed. Values are cached.

  Returns V

destroy

• destroy(): void

• Returns void

unwatch

• unwatch(callback): this

• Unregister a previously registered callback from this observable.

  Parameters

  • callback: ObservableCallback<V>

  Returns this

watch

• watch(callback, callNow?, group?): this

• Register a callback to this observable. When the value is changed, the callback will be called.

  Parameters

  • callback: ObservableCallback<V>
  • callNow: boolean = false

    If true, the callback will be called once immediately after it's registered. False by default
  • Optionalgroup: unknown

    The group to use when calling immediately. Only used if callNow is true, and is undefined by default

  Returns this