The proxy's handler object is a placeholder object which contains traps for proxies.
Methods
All traps are optional. If a trap has not been defined, the default behavior is to forward the operation to the target.
handler.getPrototypeOf()- A trap for
Object.getPrototypeOf. handler.setPrototypeOf()- A trap for
Object.setPrototypeOf. handler.isExtensible()- A trap for
Object.isExtensible. handler.preventExtensions()- A trap for
Object.preventExtensions. handler.getOwnPropertyDescriptor()- A trap for
Object.getOwnPropertyDescriptor. handler.defineProperty()- A trap for
Object.defineProperty. handler.has()- A trap for the
inoperator. handler.get()- A trap for getting property values.
handler.set()- A trap for setting property values.
handler.deleteProperty()- A trap for the
deleteoperator. handler.ownKeys()- A trap for
Object.getOwnPropertyNames. handler.apply()- A trap for a function call.
handler.construct()- A trap for the
newoperator.
Some non-standard traps are obsolete and have been removed.
Specifications
| Specification | Status | Comment |
|---|---|---|
| ECMAScript 2015 (6th Edition, ECMA-262) The definition of 'Proxy Object Internal Methods and Internal Slots' in that specification. |
Standard | Initial definition. |
| ECMAScript 2017 Draft (ECMA-262) The definition of 'Proxy Object Internal Methods and Internal Slots' in that specification. |
Draft | The enumerate handler has been removed. |
Browser compatibility
| Feature | Chrome | Firefox (Gecko) | Internet Explorer | Opera | Safari |
|---|---|---|---|---|---|
| Basic support | 49 [1] | 18 (18) | 12 | No support | No support |
| Feature | Android | Chrome for Android | Firefox Mobile (Gecko) | IE Mobile | Opera Mobile | Safari Mobile |
|---|---|---|---|---|---|---|
| Basic support | No support | No support | 18 (18) | No support | No support | No support |
[1] Enabled by default.