dart - NgComponent: How to get component instance from DOM element?

Question

I've created an NgComponent and have declared it in the markup. Is it possible to query the component element and get the associated NgComponent instance?

Answer 1

通常你不需要通过元素访问控制器。也就是说，有自省 API。ngDirectives将返回给定节点的所有控制器的列表。但是 AFAIK 它仅用于调试。

或者，如果您需要访问子组件/指令/控制器，请考虑以下模式：

<tabs>
  <pane title="Pane A">...</pane>
  <pane title="Pane B">...</pane>
  <pane title="Pane C">...</pane>
</tabs>

@NgComponent(
    selector: 'tabs',
    visibility: NgDirective.DIRECT_CHILDREN_VISIBILITY
)
class Tabs {
  List<Pane> _panes;

  registerPane(Pane pane) {
    _panes.add(pane);
  }
}

@NgComponent(
    selector: 'pane'
)
class Pane {
  @NgAttr('title')
  String title;

  Pane(Tabs tabs) {
    tabs.registerPane(this);
  }
}

当窗格被实例化时，它们向选项卡容器自我注册，随后选项卡容器可以访问窗格实例。