Angular 2.x watching for variable change

You might want to implement the OnChanges interface and implement the ngOnChanges() method.
This method is called whenever one of the components input or output binding value changes.
See also https://angular.io/docs/ts/latest/guide/lifecycle-hooks.html

Dart code example

  @Input() bool fixed;

  @override
  void ngOnChanges(Map<String, SimpleChange> changes) {
    print(changes);
  }