Js 职责链模式 简单理解

js 职责链模式 的简单理解。大叔的代码太高深了，不好理解。

function Handler(s) {
    this.successor = s || null;
    this.handle = function () {
        if (this.successor) {
            this.successor.handle();
        }
    }
}

var app = new Handler({
    handle: function () {
        console.log('app handle');
    }
});

var dialog = new Handler(app);
dialog.handle = function () {
    console.log('dialog before ...');
    app.handle(this);
    console.log('dialog after ...');
};
var button = new Handler(dialog);
button.handle = function () {
    console.log('button before ...');
    dialog.handle(this);
    console.log('button after ...');
};

button.handle();

输出结果：

button before ...
dialog before ...
app handle
dialog after ...
button after ...

引用　　http://www.cnblogs.com/TomXu/archive/2012/04/10/2435381.html