扩展功能javascript的功能

Question

I have a function that is declared like this:

    function Plugin(option) {
       //logic here
    }
    $.fn.validator = Plugin

I need to extend this function with some logic so that it does something more like this:

    function Plugin(option) {
       if (myvariable == true)
       {
           //seperate logic
           return;
       }
       //logic here
    }

The trick is that I need to add that if statement into the function dynamically, the code that has the Plugin function gets updated frequently and I don't want to re-add that logic every time the file changes. As of right now I just create the whole function with all the logic and replace the old one with it. But this seems like a lot of wasted code. I was hoping there was a way to simply merge them, so I tried.

    function Plugin(option) {
       //logic here
    }
    function extendedPlugin(option) {
       //seperate logic here
    }
  $.fn.validator = $.extend(Plugin, extendedPlugin);
    //or
  $.fn.extend($.fn.validator, extendedPlugin)

I've tried a couple variations of that logic at the bottom but it just returns the first function every time, is there a way to merge them since functions are technically objects aren't they? I think I may need to do something with prototypes but my understanding of them is still very limited.

Answer 1

If Plugin is directly written in some third party code, you can rename and replace the old function:

var OldPlugin = Plugin;
Plugin = function(option)
{
    if (myvariable == true)
    {
        //seperate logic
        return /* anything? */;
    }
    return OldPlugin.apply(this, arguments);
}

Of course, any assigned references to OldPlugin must be replaced too:

$.fn.validator = Plugin; // After redefining "Plugin"

If Plugin is not directly written anywhere, but only called via $.fn.validator , then I would leave the original function intact and simply assign a new function to $.fn.validator , from where you can call the original Plugin function.

Answer 2

Is there a reason you can't simply call the old function from the extended one?

function Plugin(option) {
   //logic here
}
function extendedPlugin(option) {
   //seperate logic here
   // then call Plugin?
   return Plugin.call(this, option);
}

If you need the new function to have the original name, you can instead do what @Siguza answered

Answer 3

I think if you use JsonNode it will be more easy try doing this way

function plugin(option){
   option.execute();
}

$.fn.validator = Plugin;

And implement in this way

var process1 = {
       "execute":function(){
           alert('hello proccess #1');
       }
      };
var process2 = {
       "execute":function(){
           alert('hello process #2');
       }
      };

$.fn.validator(process1);
$.fn.validator(process2);

Or

if(myvariable){
     $.fn.validator(process1);
}else{
    $.fn.validator(process2);
}