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| -rw-r--r-- | files/zh-cn/web/api/event/composed/index.html | 53 |
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diff --git a/files/zh-cn/web/api/event/composed/index.html b/files/zh-cn/web/api/event/composed/index.html index afc72ea0be..01b1e60875 100644 --- a/files/zh-cn/web/api/event/composed/index.html +++ b/files/zh-cn/web/api/event/composed/index.html @@ -3,7 +3,7 @@ title: Event.composed slug: Web/API/Event/composed translation_of: Web/API/Event/composed --- -<p>{{SeeCompatTable}}{{APIRef("Shadow DOM")}}</p> +<p>{{APIRef("Shadow DOM")}}</p> <p>{{domxref("Event")}} 接口的只读属性 <strong><code>composed</code></strong> 返回一个 {{jsxref("Boolean")}} 值，用来指示该事件是否可以从 Shadow DOM 传递到一般的 DOM。</p> @@ -21,6 +21,57 @@ translation_of: Web/API/Event/composed <p>如果属性值为 <code>false</code>，那么事件将不会跨越 shadow DOM 的边界传播。</p> +<h2 id="例子">例子</h2> + +<p>在我们的组合组合路径示例（实时查看）中，我们定义了两个不重要的自定义元素 <code><open-shadow></code> 和 <code><closed-shadow></code>，它们都将获取其 <code>text</code> 属性的内容并将它们作为元素的文本内容插入到元素的 shadow DOM 中。两者之间的唯一区别是它们的阴影根附加了它们的模式分别设置为 open 和 closed。</p> + +<p>第一个定义如下所示：</p> + +<pre class="brush: js">customElements.define('open-shadow', + class extends HTMLElement { + constructor() { + super(); + + let pElem = document.createElement('p'); + pElem.textContent = this.getAttribute('text'); + + let shadowRoot = this.attachShadow({mode: 'open'}) + .appendChild(pElem); + + } +});</pre> + +<p>我们将他们插入我们的页面当中：</p> + +<pre class="brush: html"><open-shadow text="I have an open shadow root"></open-shadow> +<closed-shadow text="I have a closed shadow root"></closed-shadow></pre> + + <p>然后在 <code>html</code> 标签上监听 click 事件：</p> + +<pre class="brush: js">document.querySelector('html').addEventListener('click',function(e) { + console.log(e.composed); + console.log(e.composedPath()); +});</pre> + +<p>当我们点击 <code><open-shadow></code> 和 <code><closed-shadow></code> 元素时候我们会注意到：</p> + +<ol> + <li>The <code>composed</code> property returns <code>true</code> because the + <code>click</code> event is always able to propagate across shadow boundaries.</li> + <li>You'll notice a difference in the value of <code>composedPath</code> for the two + elements.</li> +</ol> + +<p><code><open-shadow></code> 元素的组合路径是：</p> + +<pre>Array [ p, ShadowRoot, open-shadow, body, html, HTMLDocument https://mdn.github.io/web-components-examples/composed-composed-path/, Window ]</pre> + +<p>而 <code><closed-shadow></code> 元素的组合路径是：</p> + +<pre>Array [ closed-shadow, body, html, HTMLDocument https://mdn.github.io/web-components-examples/composed-composed-path/, Window ]</pre> + +<p>第二种情况下，监听器只会捕获到 <code><closed-shadow></code> 元素本身，而不会去继续捕捉这个其中的节点。</p> + <h2 id="规范">规范</h2> <table class="standard-table"> |