AsyncPipe class

An async pipe awaits for a value from a Future or Stream. When a value is received, the async pipe marks the component to be checked for changes.

Example

@Component(
    selector: 'async-greeter',
    template: '''
      <div>
        <p>Wait for it ... {{ $pipe.async(greeting) }}</p>
        <button [disabled]="!done" (click)="tryAgain()">Try Again!</button>
      </div>''')
class AsyncGreeterPipe {
  static const _delay = const Duration(seconds: 2);

  Future<String> greeting;
  bool done;

  AsyncGreeterPipe() {
    tryAgain();
  }

  String greet() {
    done = true;
    return "Hi!";
  }

  void tryAgain() {
    done = false;
    greeting = new Future<String>.delayed(_delay, greet);
  }
}

@Component(
    selector: 'async-time',
    template: "<p>Time: {{ $pipe.date($pipe.async(time), 'mediumTime') }}</p>") //
class AsyncTimePipe {
  static const _delay = const Duration(seconds: 1);
  final Stream<DateTime> time =
      new Stream.periodic(_delay, (_) => new DateTime.now());
}

Implemented types

• OnDestroy

Annotations

• @Pipe('async', pure: false)

Constructors

AsyncPipe(ChangeDetectorRef _ref)

Properties

hashCode → int

The hash code for this object.

no setter, inherited

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

Methods

ngOnDestroy() → void

Executed before the directive is removed from the DOM and destroyed.

override

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

toString() → String

A string representation of this object.

inherited

transform(dynamic obj) → dynamic

Operators

operator ==(Object other) → bool

The equality operator.

inherited