The Proxy.revocable()
method is used to create a revocable Proxy
object.
Syntax
Proxy.revocable(target, handler);
Parameters
target
- A target object (can be any sort of object, including a native array, a function or even another proxy) to wrap with
Proxy
. handler
- An object whose properties are functions which define the behavior of the proxy when an operation is performed on it.
Return value
A newly created revocable Proxy
object is returned.
Description
A revocable Proxy
is an object with following two properties {proxy: proxy, revoke: revoke}
.
proxy
- A Proxy object created with
new Proxy(target, handler)
call. revoke
- A function with no argument to invalidate (switch off) the
proxy
.
If the revoke()
function gets called, the proxy becomes unusable: Any trap to a handler will throw a TypeError
. Once a proxy is revoked, it will remain revoked and can be garbage collected. Calling revoke()
again has no effect.
Examples
var revocable = Proxy.revocable({}, { get: function(target, name) { return "[[" + name + "]]"; } }); var proxy = revocable.proxy; console.log(proxy.foo); // "[[foo]]" revocable.revoke(); console.log(proxy.foo); // TypeError is thrown proxy.foo = 1 // TypeError again delete proxy.foo; // still TypeError typeof proxy // "object", typeof doesn't trigger any trap
Specifications
Specification | Status | Comment |
---|---|---|
ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'Proxy Revocation Functions' in that specification. |
Standard | Initial definition. |
ECMAScript Latest Draft (ECMA-262) The definition of 'Proxy Revocation Functions' in that specification. |
Living Standard |
Browser compatibility
The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Feature | Chrome | Edge | Firefox | Internet Explorer | Opera | Safari |
---|---|---|---|---|---|---|
Basic support | Yes | Yes | 34 | No | Yes | 10 |
Feature | Android webview | Chrome for Android | Edge mobile | Firefox for Android | IE mobile | Opera Android | iOS Safari |
---|---|---|---|---|---|---|---|
Basic support | Yes | Yes | Yes | 34 | No | Yes | 10 |
See also
Document Tags and Contributors
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Contributors to this page:
fscholz,
jameshkramer,
SphinxKnight,
robbiespeed,
kdex,
ibratoev,
north-is-northwest,
xushu42,
ziyunfei,
arai
Last updated by:
fscholz,