views:

5046

answers:

2

Javascript code:

function doSomething(v1,v2){ //blah; }

function SomeClass(callbackFunction,callbackFuncParameters(*Array*))={
   this.callback = callbackFunction;
   this.method = function(){
       this.callback(parameters[0],parameters[1])  // *.*
   }
}

var obj = new SomeClass( doSomething, Array('v1text','v2text') );

The problem is if I change function doSomething to

function doSomething(v1,v2,v3){ //blah; }

I have to change the corresponding line (marked as //*.*) in SomeClass to

this.callback(parameters[0],parameters[1],parameters[2]);

What can be done to avoid the (*.*) line to be changed no matter how the number of 'doSomething' function's parameters is changed?

Thanks a lot!

+5  A: 

You probably want to use the apply method

this.callback.apply(this, parameters);

The first parameter to apply indicates the value of "this" within the callback and can be set to any value.

krosenvold
Works! Thank you.
Shawn
Im a little confused on how to use this functionality. What I want to do is pass a function to a callback like this - myfunction(function(myele) { //use myele }). So I am passing an anon callback function here with the myele parameter being passed to it. How would I do this with your code above?
Metropolis
A: 

Why you just don't pass the parameters array as a parameter?

CMS
Maybe because (user+"@"+host+path) makes more sense than (args[1]+"@"+args[0]+args[2]) ?
some