does jquery have an equivalent of dojo.hitch()?

Forgive my ignorance as I am not as familiar with jquery. Is there an equivalent to dojo.hitch()? It returns a function that is guaranteed to be executed in the given scope.

-- edit -- As requested, here is an example. I use hitch very frequently to ensure callbacks are executed within the right object. For example, let's say I have a utility method called doSomethingAsync and I p开发者_C百科ass it a callback function. With hitch, I can make sure the function is executed within a particular scope even if the utility method performs ajax calls and so forth:

expectedScopeObj = {
   flag: true,
   callback: function(){console.debug(this.flag);},
   main: function() {
     // without hitch the callback function would not find flag  
     core.util.doSomethingAsync(dojo.hitch(this, this.callback));
   }
}

Without hitch, the callback function could possibly be executed in a different scope and an error would be thrown with this.flag being undefined. However, with hitch it is guaranteed to be executed within execptedScopeObj.

I know this has been answered, but not correctly. jQuery.proxy is what you are looking for I believe.

UPDATE

Many, many years later after lots of JavaScript work, and after stripping out my usage of jQuery since browser compatibility has become less of an issue, I would recommend using Function.prototype.bind over jQuery.proxy, as @bobince suggested. While this is still the correct answer to the original question, I feel obligated to direct people to a vanilla solution rather than relying on jQuery.

[ADMIN EDIT: Note the much more popular answer, below.—danorton]

I'd go for function.bind, which will be the standard way of doing this in future versions of JavaScript. As well as fixing this , it allows you to pass arguments through to the target functions.

Until all browsers support it natively, you can hack support in yourself.

No. Not in 1.3.2, at least, as I don't know about 1.4. There are, however, some plugins:

(function($) {
  $.fn.hitch = function(ev, fn, scope) {
    return this.bind(ev, function() {
      return fn.apply(scope || this, Array.prototype.slice.call(arguments));
    });
  };
})(jQuery);  

The function.bind mentioned by bobince is a pretty useful tool. You could use it to rewrite the hitch function pretty simply:

// The .bind method from Prototype.js 
if (!Function.prototype.bind) { // check if native implementation available
  Function.prototype.bind = function(){ 
    var fn = this, args = Array.prototype.slice.call(arguments),
        object = args.shift(); 
    return function(){ 
      return fn.apply(object, 
        args.concat(Array.prototype.slice.call(arguments))); 
    }; 
  };
}

jQuery.hitch = function(scope, fn) {
  if (typeof fn == "string") fn = scope[fn];
  if (fn && fn.bind) return fn.bind(scope);
};

At least based on the doc page you linked, this is how I saw the function working...

//why not just:
(function($){
  $.hitch = function(scope, fn){
    return function(){
      return fn.apply(scope, arguments);
    }
  }
})(JQuery);
//This works exactly like Dojo's hitch from what I can tell.

/**
 * This is for simulate dojo.hitch.
 * @param $
 */
(function($) {
    $.hitch = function(context, func) {
        var args = Array.prototype.slice.call(arguments, 
                2/*Remove context, and func*/);

        return function() {
            return func.apply(context, 
                    Array.prototype.concat.call(args, arguments));
        };
    };
})(jQuery);

In my mind, hitch in Dojo is more complex,

e.g.,

function f(a,b,c){return a+b*c}
var newF = hitch(null,f,1,undefined,3);
newF(2) /*1+2*3*/