执行功能时通知jQuery/Javascript

本文介绍了执行功能时通知jQuery/Javascript的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

var f = function() {
    // Do something useful here
};

有没有一种方法可以观察"此功能，并在执行该功能时得到通知?类似于jQuery中的 bind ，但是我想 bind 函数而不是dom事件?

Is there a way to 'observe' this function, and get notified when it is executed? Something similar to bind in jQuery, but I want to bind functions and not dom events?

我不想要这样的东西:

var f = function() {
    // Do something useful here
    notifyObserver();
};

但我想要是这样的:

f.bind(function() {
    alert('F was executed.');
});

推荐答案

您可以将f替换为调用notifyObserver的函数:

You could replace f with a function that calls notifyObserver:

f = (function(oldF){
      return function(){
        notifyObserver();
        oldF();
      };
    })(f);

那样，您无需修改(旧的)f本身.当然，这不包括您的 bind 功能.我可能为此创建了某种管理器类，您可以在其中注册事件处理程序

That way you don't need to modify (the old) f itself. This doesn't include your bind functionality, of course. I'd probably create some kind of manager class for this where you can register event handlers

manager.bind('f', function(){...});

创建包装器函数看起来更像

And creating the wrapper function would look more like

f = (function(oldF){
      return function(){
        manager.notify('f');
        oldF();
      };
    })(f);

您可以概括包装器的创建:

You can generalize the creation of the wrapper:

function wrap(methodToWrap, eventName){
    return function(){
        manager.notify(eventName);
        return methodToWrap.apply(this, arguments);
    }
}

(这可用于任意数量的参数和返回值！)

(This works with any number of arguments and return values!)

然后执行以下操作:

f = wrap(f, "f");

请参阅: http://jsfiddle.net/NBefc/2/(已更新，没有返回值)

See: http://jsfiddle.net/NBefc/2/ (updated, no with return values)

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