Web/JavaScript/Reference/Global objects/Proxy/revocable

The Proxy.revocable() method is used to create a revocable Proxy object.

Syntax

Proxy.revocable(target, handler);

Parameters

target: A target object to wrap with Proxy. It can be any sort of object, including a native array, a function, or even another proxy.
handler: An object whose properties are functions define the behavior of proxy p 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

Using Proxy.revocable

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
ECMAScript (ECMA-262)The definition of 'Proxy Revocation Functions' in that specification.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile						Server
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet	Node.js
`revocable`	Chrome Full support 63	Edge Full support 12	Firefox Full support 34	IE No support No	Opera Full support 50	Safari Full support 10	WebView Android Full support 63	Chrome Android Full support 63	Firefox Android Full support 34	Opera Android Full support 46	Safari iOS Full support 10	Samsung Internet Android Full support 8.0	nodejs Full support 6.0.0

Legend

Full support: Full support
No support: No support