class ObservableObjectmethod

observeAsync()

Observes one or more targets asynchronously, batching or debouncing/throttling updates.

observeAsync<T extends (string & keyof this) | Binding>(
  target: T,
  observer: ObservableObject.AsyncObserver<
    [ObservableObject.InferObservedValue<this, T>]
  >,
): void;

observeAsync<T1 extends (string & keyof this) | Binding>(
  targets: [T1],
  observer: ObservableObject.AsyncObserver<
    [ObservableObject.InferObservedValue<this, T1>]
  >,
): void;

observeAsync<
  T1 extends (string & keyof this) | Binding,
  T2 extends (string & keyof this) | Binding,
>(
  targets: [T1, T2],
  observer: ObservableObject.AsyncObserver<
    [
      ObservableObject.InferObservedValue<this, T1>,
      ObservableObject.InferObservedValue<this, T2>,
    ]
  >,
): void;

observeAsync<
  T1 extends (string & keyof this) | Binding,
  T2 extends (string & keyof this) | Binding,
  T3 extends (string & keyof this) | Binding,
>(
  targets: [T1, T2, T3],
  observer: ObservableObject.AsyncObserver<
    [
      ObservableObject.InferObservedValue<this, T1>,
      ObservableObject.InferObservedValue<this, T2>,
      ObservableObject.InferObservedValue<this, T3>,
    ]
  >,
): void;

observeAsync<
  T1 extends (string & keyof this) | Binding,
  T2 extends (string & keyof this) | Binding,
  T3 extends (string & keyof this) | Binding,
  T4 extends (string & keyof this) | Binding,
>(
  targets: [T1, T2, T3, T4],
  observer: ObservableObject.AsyncObserver<
    [
      ObservableObject.InferObservedValue<this, T1>,
      ObservableObject.InferObservedValue<this, T2>,
      ObservableObject.InferObservedValue<this, T3>,
      ObservableObject.InferObservedValue<this, T4>,
    ]
  >,
): void;

observeAsync(
  targets: (string | Binding)[],
  observer: ObservableObject.AsyncObserver<any[]>,
): void;

Notes

• Use this method to observe multiple targets or to debounce/throttle updates.
• The observer function is called asynchronously after changes are batched.

Parameters

• target — A property name, binding, or array of property names and/or bindings
• observer — A function that will be called with the current values, or an object with update, debounce, and/or throttle options

Examples

// Observe multiple targets, batching updates
this.observeAsync(["foo", "bar"], (foo, bar) => {
  // called once per tick when foo and/or bar change
});

// Debounce a single target (e.g., search-as-you-type)
this.observeAsync("searchQuery", {
  update: (query) => this.search(query),
  debounce: 300,
});

// Throttle updates (e.g., resize handlers)
this.observeAsync(new Binding("viewport.width"), {
  update: (width) => this.handleResize(width),
  throttle: 100,
});

Related

• class ObservableObject
  The base class of all observable objects, which can be placed into a tree structure to enable event handling and data binding.