javascript - 如何在 JavaScript 的构造函数中定义对象的原型(prototype)？

Question

我要创建一个对象构造函数，并将一个对象作为其属性之一，并希望向该对象的原型(prototype)添加方法。

像这样定义它是行不通的，因为该对象是从对象文字而不是构造函数实例化的:

 function Resource (options) {
    this.self = this;
    this.options = options || {};

    .. other options. ...
    
    // service object that I want to add functions to its prototype
    this.service = {
        request: new XMLHttpRequest(),
        requestMethod: options.requestMethod ||'GET',
    },
    // using prototype actually creates an object called prototype 
    // as a property of the service object.
    this.service.prototype = {
        dataToNode: function(element, parent, data){
            var toAppend = document.createElement(element);
            toAppend.innerHTML = data;
            return parent.appendChild(toAppend);
        },
} 

切入主题并像这样使用 __proto__ 是可行的，但 __proto__ 已被贬值。

如何在不使用 __proto__ 的情况下添加到对象原型(prototype)？

function Resource (options) {
    this.self = this;
    this.options = options || {};

    .. other options. ...
    
    // service object that I want to add functions to its prototype
    this.service = {
        request: new XMLHttpRequest(),
        requestMethod: options.requestMethod ||'GET',
    },
    // using __proto__ works but its deprciated
    this.service.__proto__ = {
        dataToNode: function(element, parent, data){
            var toAppend = document.createElement(element);
            toAppend.innerHTML = data;
            return parent.appendChild(toAppend);
        },
}

Answer 1

function Service(options) {
    this.request = new XMLHttpRequest();
    this.requestMethod = options.requestMethod || 'GET';
}

Service.prototype.dataToNode = function(element, parent, data){
    var toAppend = document.createElement(element);
    toAppend.innerHTML = data;
    return parent.appendChild(toAppend);
};

function Resource (options) {
    this.options = options || {};
    this.service = new Service(this.options);
}