getJSON and variable scope in javascript

Question

Hi!
In order to make function calls to our back-end php code we've implemented something called an ActionProxy like this:

function ActionProxy(action, input, callback){  
    $.post("ActionProxy.php?method="+action, 
        { data: input},   
            function(data, textStatus, XMLHttpRequest){
                        //return data.ResponseWhatever
                        }
});

The problem we're having is that using data outside the ActionProxy is impossible due to variable scope limitations (we assume), setting
var res = data.ResponseWhatever
or
return data.ResponseWhatever

is pretty futile. How would one handle these responses most appropriately so that functions calling the actionproxy can access the response values?

Answer 1

You could use window.ResponseWhatever = data.ResponseWhatever, however, this is not the smartest thing to do. What you want is to do something like this:

function ActionProxy(action, input, callback){
    $.post("ActionProxy.php?method="+action, {data:input},
        function(data, textStatus, xhr){callback(data);});
}

Note: I'm no jQuery-guru, so I might have gotten some of the jQuery-parts wrongly, but the point is that where you want to call return data you instead call callback(data);.