更改私人课程方法

Question

I am attempting to change the behavior of a jquery plugin without actually changing the source. For the purposes of this question, I constructed a simple example that illustrates my problem. If a have script file that attaches a class instance generator to a global variable like this:

(function(){

window.newMyClass = function(){
    return new myclass();
}

function myclass(){
    var privateMethod = function(){
        return "private";
    }
    this.publicMethod = function(){
        return privateMethod();
    }
}
})()

If I then get new instance of myclass with var instance = window.newMyClass() , is there any way to override the behavior of privateMethod on instance , such that instance.publicMethod() would call my overridden function? I was thinking I could subclass myclass, but since the myclass constructor is scoped to the immediately invoked function expression, I don't know how to do that.

Is it better just to change the plugin source? The problem with that is I'd have to host it myself instead of using a CDN, as well as re-implement the change every time an update is released.

Answer 1

I don't know if I understood well this. Probably not, because there is no mistery with that:

(function(){

window.newMyClass = function(){
    return new myclass()
}

function myclass(){
    var privateMethod = function(){
        return "private";
    }
    this.publicMethod = function(){
        return privateMethod();
    }
}
})();

var instance = window.newMyClass();

instance.publicMethod = function(){
        return "new method";
}

console.log(instance.publicMethod());

FIDDLE: http://jsfiddle.net/r9evbzd2/1/