handler.deleteProperty() 方法主要用于拦截 delete 运算命令。
const proxy = new Proxy(target, {deleteProperty: function(target, property) {// do something},});
| 参数 | 说明 | 类型 |
|---|---|---|
target | 目标对象 | object |
property | 待删除的属性名 | string |
该方法会拦截目标对象的以下操作：
delete proxy[foo] 和 delete proxy.fooReflect.deleteProperty()如果违背了以下的约束，proxy 会抛出 TypeError 异常：
下面示例为删除第一个字符为下划线的属性会报错。
const handler = {deleteProperty(target, key) {invariant(key, 'delete');delete target[key];return true;},};function invariant(key, action) {if (key[0] === '_') {throw new Error(`Invalid attempt to ${action} private "${key}" property`);}}const target = { _prop: 'foo' };const proxy = new Proxy(target, handler);delete proxy._prop;// Uncaught Error: Invalid attempt to delete private "_prop" property