The handler.apply()
method is a trap for a function call.
handler.apply()
Try it
Syntax
new Proxy(target, { apply: function(target, thisArg, argumentsList) { } });
Parameters
The following parameters are passed to the apply()
method. this
is bound to the handler.
-
target
-
The target callable object.
-
thisArg
-
The
this
argument for the call. -
argumentsList
-
The list of arguments for the call.
Return value
The apply()
method can return any value.
Description
The handler.apply()
method is a trap for a function call.
Interceptions
This trap can intercept these operations:
proxy(...args)
-
Function.prototype.apply()
andFunction.prototype.call()
Reflect.apply()
Invariants
If the following invariants are violated, the proxy will throw a TypeError
.
The target
must be a callable itself. That is, it must be a function object.
Examples
Trapping a function call
The following code traps a function call.
const p = new Proxy(function() {}, { apply: function(target, thisArg, argumentsList) { console.log('called: ' + argumentsList.join(', ')); return argumentsList[0] + argumentsList[1] + argumentsList[2]; } }); console.log(p(1, 2, 3)); // "called: 1, 2, 3" // 6
Specifications
Specification |
---|
ECMAScript Language Specification # sec-proxy-object-internal-methods-and-internal-slots-call-thisargument-argumentslist |
Browser compatibility
Desktop | Mobile | Server | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Chrome | Edge | Firefox | Internet Explorer | Opera | Safari | WebView Android | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | Deno | Node.js | |
apply |
49
|
12
|
18
|
No
|
36
|
10
|
49
|
49
|
18
|
36
|
10
|
5.0
|
1.0
|
6.0.0
|
See also
© 2005–2022 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Proxy/Proxy/apply