Making data types iterable in Dart

components.dart

@CustomTag('x-note-element')
class NoteElement extends LIElement with Polymer, Observable {
  @published Note note;
  NoteElement.created() : super.created();
}

@CustomTag('x-notebook-element')
class NotebookElement extends PolymerElement {
  @published Notebook notebook = new Notebook(new List<Note>());
  NotebookElement.created() : super.created();
}

components.html

<polymer-element name="x-note-element" extends="li">
  <template>
    <h3>{{note.title}}</h3>
    <p>{{note.content}}</p>
  </template>

  <script ...></script>
</polymer-element>

<polymer-element name="x-notebook-element">
  <template>
    <ul>
      <template repeat="{{note in notebook}}">
        <li is="x-note-element" note="{{note}}"></li>
      </template>
    </ul>
  </template>
  
  <script ...></script>
</polymer-element>

models.dart

class Note {
  String title;
  String content;
  Note(this.title, this.content);
}

class Notebook extends Object with IterableMixin<Note> {
  List<Note> notes;
  Iterator get iterator => notes.iterator;
  Notebook(this.notes);
}