blob: 4a2279fbdf24b3a790b58cf381234312bdcab309 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
|
---
title: CustomElementRegistry
slug: Web/API/CustomElementRegistry
tags:
- API
- CustomElementRegistry
- Interface
- Web Components
translation_of: Web/API/CustomElementRegistry
---
<div>{{DefaultAPISidebar("Web Components")}}</div>
<p><strong><code>CustomElementRegistry</code></strong>接口提供注册自定义元素和查询已注册元素的方法。要获取它的实例，请使用 {{domxref("window.customElements")}}属性。</p>
<h2 id="方法">方法</h2>
<dl>
<dt>{{domxref("CustomElementRegistry.define()")}}</dt>
<dd>定义一个新的<a href="/zh-CN/docs/Web/Web_Components/Custom_Elements">自定义元素</a>。</dd>
<dt>{{domxref("CustomElementRegistry.get()")}}</dt>
<dd>返回指定自定义元素的构造函数，如果未定义自定义元素，则返回<code>undefined</code>。</dd>
<dt>{{domxref("CustomElementRegistry.upgrade()")}}</dt>
<dd>Upgrades a custom element directly, even before it is connected to its shadow root.</dd>
<dt>{{domxref("CustomElementRegistry.whenDefined()")}}</dt>
<dd>返回当使用给定名称定义自定义元素时将会执行的 {{jsxref("Promise", "promise")}}。（如果已经定义了这样一个自定义元素，那么立即执行返回的 promise。）</dd>
</dl>
<h2 id="示例">示例</h2>
<p>以下代码来自我们的 <a href="https://github.com/mdn/web-components-examples/tree/master/word-count-web-component">word-count-web-component</a> 示例（<a href="https://mdn.github.io/web-components-examples/word-count-web-component/">see it live also</a>）。 请注意我们如何使用 {{domxref("CustomElementRegistry.define()")}} 方法在创建其类后定义自定义元素。</p>
<pre class="brush: js">// Create a class for the element
class WordCount extends HTMLParagraphElement {
constructor() {
// Always call super first in constructor
super();
// count words in element's parent element
var wcParent = this.parentNode;
function countWords(node){
var text = node.innerText || node.textContent
return text.split(/\s+/g).length;
}
var count = 'Words: ' + countWords(wcParent);
// Create a shadow root
var shadow = this.attachShadow({mode: 'open'});
// Create text node and add word count to it
var text = document.createElement('span');
text.textContent = count;
// Append it to the shadow root
shadow.appendChild(text);
// Update count when element content changes
setInterval(function() {
var count = 'Words: ' + countWords(wcParent);
text.textContent = count;
}, 200)
}
}
// Define the new element
customElements.define('word-count', WordCount, { extends: 'p' });</pre>
<h2 id="规范">规范</h2>
<table class="standard-table">
<tbody>
<tr>
<th scope="col">规范</th>
<th scope="col">状态</th>
<th scope="col">备注</th>
</tr>
<tr>
<td>{{SpecName("HTML WHATWG", "custom-elements.html#customelementregistry", "CustomElementRegistry")}}</td>
<td>{{Spec2("HTML WHATWG")}}</td>
<td>Initial definition.</td>
</tr>
</tbody>
</table>
<h2 id="浏览器兼容性">浏览器兼容性</h2>
<p>{{Compat("api.CustomElementRegistry")}}</p>
|
