Question

我试图了解使用Shadow DOM如何在Stenciljs中影响组件生命周期方法。

我已经在Stencil入门应用程序中设置了以下示例。

<body>
  <my-app>
    <component-a>
      <component-c />
    </component-a>
    <component-b />
    </my-app> 
    ...
</body>

组件定义为：

@Component({
  tag: 'my-app',
  styleUrl: 'my-app.css'
})
@Component({
  tag: 'component-a'
})
@Component({
  tag: 'component-b'
})
@Component({
  tag: 'component-c'
})

每个组件在其每个生命周期方法中都有控制台语句。当页面加载到浏览器中而没有任何组件打开影子DOM时。

09:30:00.603 my-app.js:19 my-app  is about to be rendered
09:30:00.605 component-a.js:19 component-a  is about to be rendered
09:30:00.606 component-c.js:19 component-c  is about to be rendered
09:30:00.606 component-c.js:30 component-c  has been rendered
09:30:00.607 component-a.js:30 component-a  has been rendered
09:30:00.607 component-b.js:19 component-b  is about to be rendered
09:30:00.608 component-b.js:30 component-b  has been rendered
09:30:00.608 my-app.js:30 my-app  has been rendered

在component-a中打开Shadow DOM会更改渲染。

@Component({
  tag: 'component-a',
  shadow: true
})

控制台输出更改为：

09:33:22.840 my-app.js:19 my-app  is about to be rendered
09:33:22.842 component-a.js:19 component-a  is about to be rendered
09:33:22.843 component-b.js:19 component-b  is about to be rendered
09:33:22.843 component-b.js:30 component-b  has been rendered
09:33:22.844 component-c.js:19 component-c  is about to be rendered
09:33:22.845 component-c.js:30 component-c  has been rendered
09:33:22.845 component-a.js:30 component-a  has been rendered
09:33:22.845 my-app.js:30 my-app  has been rendered

现在在渲染组件a和组件c之前先渲染

组件b。我不确定使用Shadow DOM渲染页面如何影响此更改。

Answer 1

在我的测试中，每个请求的渲染顺序可以是三个不同的顺序之一。在任何组件上启用Shadow DOM时，我都看不到任何变化。

我使用了相同的3个组件，并刷新了页面几次。这是三种不同的输出：

Component A is about to be rendered
Component B is about to be rendered
Component B has been rendered
Component C is about to be rendered
Component C has been rendered
Component A has been rendered

-- Hard Refresh --

Component A is about to be rendered
Component C is about to be rendered
Component C has been rendered
Component A has been rendered
Component B is about to be rendered
Component B has been rendered

-- Hard Refresh --

Component B is about to be rendered
Component B has been rendered
Component A is about to be rendered
Component C is about to be rendered
Component C has been rendered
Component A has been rendered

实际上，只要遵循Lifecycle Hierarchy，就可以按照什么顺序渲染它们（至少对于componentDidLoad方法而言）。

Shadow DOM如何在Stencil.js中影响组件生命周期方法

1 个答案: