Javascript 扩展setter默认对象
就像你们都知道的按钮是一个按钮。。。点击,向上,向下,做这个,做那个。 所以我写了一些默认的按钮行为“类/对象” 外部默认按钮.js:Javascript 扩展setter默认对象,javascript,this,defineproperty,Javascript,This,Defineproperty,就像你们都知道的按钮是一个按钮。。。点击,向上,向下,做这个,做那个。 所以我写了一些默认的按钮行为“类/对象” 外部默认按钮.js: function Button(parent) { var self = this; this.enabled = true; this.visible = true; ... this.initialized = false; f_createButton(parent, self); this.i
function Button(parent) {
var self = this;
this.enabled = true;
this.visible = true;
...
this.initialized = false;
f_createButton(parent, self);
this.initialized = true;
...
}
Button.prototype = {
get initialized () {
return this._initialized;
},
set initialized(bool){
this._initialized = bool
if(this.initialized === true) {
... do default stuff
}
},
get enabled(){
return this._enabled;
},
set enabled(bool){
this._enabled = bool;
if(document.getElementById(this.id)) { // is button defined?
var mClassName = document.getElementById(this.id).children[0].className;
document.getElementById(this.id).className = (this.enabled === false) ? "button button-Gray_disabled" : "button button-" + this.defaultStyle;
document.getElementById(this.id).children[0].className = (this.enabled === false) ? mClassName + "_disabled" : mClassName.replace("_disabled","");
}
}
}
function f_createButton("", obj) {
.... create DOM element
}
在html中包含button.js并扩展按钮“类/对象”:
这几乎可以工作,但它会杀死初始化的原始按钮
Object.defineProperty(Button.prototype,"initialized", {
set : function( bool ) {
this._initialized = bool;
if(this.initialized === true) {
this.buttonStyle = "NONE";
}
}
});
如何扩展原始setter?您提出的问题似乎不寻常,但让我们试试。首先,考虑这个基类,它将在您的外部JS文件中:
// Constructor
function Button() {
var self = this;
var _initialized = false; // 'private' property manipulated by the accessors
this.initialized = false;
this.createButton();
this.initialized = true;
}
// Default prototype
Button.prototype = {
createButton: function() {
console.log(' create DOM element ');
}
}
// Default getter/setter on prototype
Object.defineProperty(Button.prototype,"initialized", {
set : function( bool ) {
console.log('this is the original setter');
this._initialized = bool;
if(this._initialized === true) {
console.log('do default stuff')
}
},
get : function() {
return this._initialized;
},
configurable : true // IMPORTANT: this will allow us to redefine it
});
如果我理解您的要求,那么您希望重新定义初始化的
访问器(getter/setter),但仍然有对旧访问器的引用。也许有更好的方法可以做到这一点,但您可以将原始访问器复制到新的访问器中,然后重新定义它:
// Keep reference to the old accessors
var original = Object.getOwnPropertyDescriptor(Button.prototype, 'initialized');
Object.defineProperty(Button.prototype, "oldInitialized", {
set : original.set,
get : original.get
});
// Redefine getter and setter
Object.defineProperty(Button.prototype, "initialized", {
set : function( bool ) {
console.log('this is the new setter');
this.oldInitialized = bool;
},
get : function() {
return this._initialized;
}
});
下面是工作中的代码:。我们的想法是不要更改外部按钮。js…im,这有点新。。。。PHP是我的语言…很简单,我想向button.js添加一些扩展功能并捕获初始化事件…也许我错了,我的代码很烂?我看你比我更了解javascript。。。有可能吗?清理我的评论,让我们重新开始。那么,你想做什么?创建新类,还是修改原始类?那么,当你重写一个setter方法时,你是想让原来的方法也运行,还是用新方法替换它呢。。。如果你看到这个,也许会更清楚,我会检查你的小提琴
// Keep reference to the old accessors
var original = Object.getOwnPropertyDescriptor(Button.prototype, 'initialized');
Object.defineProperty(Button.prototype, "oldInitialized", {
set : original.set,
get : original.get
});
// Redefine getter and setter
Object.defineProperty(Button.prototype, "initialized", {
set : function( bool ) {
console.log('this is the new setter');
this.oldInitialized = bool;
},
get : function() {
return this._initialized;
}
});