Populating derived fields in an Angular Dart component

Question

I have a component that takes a single attribute. I want to populate a field in the component with a value that is derived from this attribute. I am running into the problem

Answer 1

One possible solution is to ave the component implement NgAttachAware and define the attach() method. The value of the derived field can then be set inside attach(). I have no idea if there is a more idiomatic way to do this, but using attach() seems to work.

Here is the code:

import 'package:angular/angular.dart';

@NgComponent(
    selector: 'tokens',
    templateUrl: './component.html',
    cssUrl: './component.css',
    publishAs: 'ctrl',
    map: const {
      'text' : '@text'
    }
)
class TokensComponent implements NgAttachAware {
  String text;

  // Derived field.
  List tokens = new List();

  TokensComponent() {
    print('inside constructor, text = $text');
  }

  void attach() {
    print('inside attach(), text = $text'); // $text is no longer null.
    text.split('').forEach((char) => tokens.add(new Token(char, false)));
  }
}

class Token {
  String char;
  bool important;
  Token(this.char, this.important);
}