.l-main-section
  p.
    As mentioned earlier, you build Angular applications as a tree of nested components.
    You've seen how to create a top-level component.
    You add child components to a parent component by using them in
    the parent component's template,
    and by specifying the child component classes in the parent's list of directives.
  p.
    Given a bootstrapping template with a <parent> tag in the body,
    you can create a parent
    component that uses a <child> component like so:
  code-example(language="dart" format="linenums").
    part of making_components;
    @Component(
      selector: 'parent'
    )
    @View(
      template: '''
        <h1>{{ message }}</h1>
        <child></child>
    ''',
      directives: const[ChildComponent]
    )
    class ParentComponent {
      String message = "I'm the parent";
    }
  p You then just need to write the ChildComponent class to make it work:
  code-example(language="dart" format="linenums").
    part of making_components;
    @Component(
        selector: 'child'
    )
    @View(
        template: '''
        <p> {{ message }} </p>
    '''
    )
    class ChildComponent {
      String message = "I'm the child";
    }
  //p.
    [TODO: Motivate communication between components with iterator example that passes index to the child]