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author | Florian Merz <me@fiji-flo.de> | 2021-02-11 12:56:40 +0100 |
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committer | Florian Merz <me@fiji-flo.de> | 2021-02-11 12:56:40 +0100 |
commit | 310fd066e91f454b990372ffa30e803cc8120975 (patch) | |
tree | d5d900deb656a5da18e0b60d00f0db73f3a2e88e /files/zh-cn/web/javascript/reference/global_objects/proxy/handler/construct | |
parent | 8260a606c143e6b55a467edf017a56bdcd6cba7e (diff) | |
download | translated-content-310fd066e91f454b990372ffa30e803cc8120975.tar.gz translated-content-310fd066e91f454b990372ffa30e803cc8120975.tar.bz2 translated-content-310fd066e91f454b990372ffa30e803cc8120975.zip |
unslug zh-cn: move
Diffstat (limited to 'files/zh-cn/web/javascript/reference/global_objects/proxy/handler/construct')
-rw-r--r-- | files/zh-cn/web/javascript/reference/global_objects/proxy/handler/construct/index.html | 130 |
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diff --git a/files/zh-cn/web/javascript/reference/global_objects/proxy/handler/construct/index.html b/files/zh-cn/web/javascript/reference/global_objects/proxy/handler/construct/index.html deleted file mode 100644 index 209e9752e3..0000000000 --- a/files/zh-cn/web/javascript/reference/global_objects/proxy/handler/construct/index.html +++ /dev/null @@ -1,130 +0,0 @@ ---- -title: handler.construct() -slug: Web/JavaScript/Reference/Global_Objects/Proxy/handler/construct -translation_of: Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/construct ---- -<div>{{JSRef}}</div> - -<p><code><strong>handler.construct()</strong></code> 方法用于拦截{{jsxref("Operators/new", "new")}} 操作符. 为了使new操作符在生成的Proxy对象上生效,用于初始化代理的目标对象自身必须具有[[Construct]]内部方法(即 <code>new target</code> 必须是有效的)。</p> - -<p>{{EmbedInteractiveExample("pages/js/proxyhandler-construct.html", "taller")}}</p> - -<h2 id="语法">语法</h2> - -<pre class="brush: js">var p = new Proxy(target, { - construct: function(target, argumentsList, newTarget) { - } -}); -</pre> - -<h3 id="参数">参数</h3> - -<p>下面的参数将会传递给<code>construct</code>方法,<code>this</code>绑定在handler上。</p> - -<dl> - <dt><code>target</code></dt> - <dd>目标对象。</dd> - <dt><code>argumentsList</code></dt> - <dd>constructor的参数列表。</dd> - <dt><code>newTarget</code></dt> - <dd>最初被调用的构造函数,就上面的例子而言是p。</dd> -</dl> - -<h3 id="返回值">返回值</h3> - -<p><code>construct</code> 方法必须返回一个对象。</p> - -<h2 id="描述">描述</h2> - -<p><code><strong>handler.construct()</strong></code> 方法用于拦截 {{jsxref("Operators/new", "new")}}操作符。</p> - -<h3 id="拦截">拦截</h3> - -<p>该拦截器可以拦截以下操作:</p> - -<ul> - <li><code>new proxy(...args)</code></li> - <li>{{jsxref("Reflect.construct()")}}</li> -</ul> - -<h3 id="约束">约束</h3> - -<p>如果违反以下约定,代理将会抛出错误 {{jsxref("TypeError")}}:</p> - -<ul> - <li>必须返回一个对象.</li> -</ul> - -<h2 id="示例">示例</h2> - -<p>下面代码演示如何拦截 {{jsxref("Operators/new", "new")}} 操作。</p> - -<pre class="brush: js">var p = new Proxy(function() {}, { - construct: function(target, argumentsList, newTarget) { - console.log('called: ' + argumentsList.join(', ')); - return { value: argumentsList[0] * 10 }; - } -}); - -console.log(new p(1).value); // "called: 1" - // 10 -</pre> - -<p>下面的代码违反了约定.</p> - -<pre class="brush: js">var p = new Proxy(function() {}, { - construct: function(target, argumentsList, newTarget) { - return 1; - } -}); - -new p(); // TypeError is thrown -</pre> - -<p>下面的代码未能正确的初始化Proxy。Proxy初始化时,传给它的<code>target</code> 必须具有一个有效的constructor供<code>new</code>操作符调用。</p> - -<pre class="brush: js">var p = new Proxy({}, { - construct: function(target, argumentsList, newTarget) { - return {}; - } -}); - -new p(); // TypeError is thrown, "p" is not a constructor -</pre> - -<h2 id="规范">规范</h2> - -<table class="standard-table"> - <tbody> - <tr> - <th scope="col">Specification</th> - <th scope="col">Status</th> - <th scope="col">Comment</th> - </tr> - <tr> - <td>{{SpecName('ES2015', '#sec-proxy-object-internal-methods-and-internal-slots-construct-argumentslist-newtarget', '[[Construct]]')}}</td> - <td>{{Spec2('ES2015')}}</td> - <td>Initial definition.</td> - </tr> - <tr> - <td>{{SpecName('ESDraft', '#sec-proxy-object-internal-methods-and-internal-slots-construct-argumentslist-newtarget', '[[Construct]]')}}</td> - <td>{{Spec2('ESDraft')}}</td> - <td> </td> - </tr> - </tbody> -</table> - -<h2 id="浏览器兼容性">浏览器兼容性</h2> - -<div>{{Compat("javascript.builtins.Proxy.handler.construct")}}</div> - -<div id="compat-mobile"> </div> - -<h2 id="相关主题">相关主题</h2> - -<ul> - <li>{{jsxref("Proxy")}}</li> - <li>{{jsxref("Proxy.handler", "handler")}}</li> - <li>{{jsxref("Operators/new", "new")}} operator.</li> - <li>{{jsxref("Reflect.construct()")}}</li> -</ul> |