如何定义类似于getter和setter的deleter答案

【问题标题】：How to define deleter similar to getter and setter如何定义类似于getter和setter的deleter
【发布时间】：2021-10-06 04:30:27
【问题描述】：

我有一个使用代理为嵌套对象设置的代码。我也想处理删除。我不知道该怎么做。

在下面的代码中，我使用代理来定义 getter 和 setter，但我也想在属性被删除时点击。

/*
    This function takes an object and converts to a proxy object.
    It also takes care of proxying nested objectsa and array.
*/
let getProxy = (original) => {
    return new Proxy(original, {
        get(target, name, receiver) {
            let rv = Reflect.get(target, name, receiver);
            return rv;
        },
        set(target, name, value, receiver) {
            // Proxies new objects 
            if(typeof value === "object"){
                value = getProxy(value);
            }
            return Reflect.set(target, name, value, receiver);
        }
    })
}

let first = {};
let proxy = getProxy(first);

/*
    Here are the tests
*/

proxy.name={}                               // object
proxy.name.first={}                         // nested object
proxy.name.first.names=[]                   // nested array 
proxy.name.first.names[0]={first:"vetri"}   // nested array with an object

/*
    Here are the serialised values
*/
console.log(JSON.stringify(first))  // {"name":{"first":{"names":[{"first":"vetri"}]}}}
console.log(JSON.stringify(proxy))  // {"name":{"first":{"names":[{"first":"vetri"}]}}}

【问题讨论】：

标签： javascript proxy metaprogramming

【解决方案1】：

发现 deleteProperty 处理程序会处理它

/*
    This function takes an object and converts to a proxy object.
    It also takes care of proxying nested objectsa and array.
*/
let getProxy = (original) => {
    return new Proxy(original, {
        get(target, name, receiver) {
            let rv = Reflect.get(target, name, receiver);
            return rv;
        },
        set(target, name, value, receiver) {
            // Proxies new objects 
            if(typeof value === "object"){
                value = getProxy(value);
            }
            return Reflect.set(target, name, value, receiver);
        },
        deleteProperty: function(target, property) {
            if (property in target) {
                delete target[property];
            }
        }
    })
}

let first = {};
let proxy = getProxy(first);

/*
    Here are the tests
*/

proxy.name={}                               // object
proxy.name.first={}                         // nested object
proxy.name.first.names=[]                   // nested array 
proxy.name.first.names[0]={first:"vetri"}   // nested array with an object

/*
    Here are the serialised values
*/
console.log(JSON.stringify(first))  // {"name":{"first":{"names":[{"first":"vetri"}]}}}
console.log(JSON.stringify(proxy))  // {"name":{"first":{"names":[{"first":"vetri"}]}}}
delete proxy.name.first.names[0].first // call goes through the delete handler

【讨论】：