Question

Possible Duplicate:
jQuery: Return data after ajax call success

first of all I’m not very experienced with JS or jQuery, but as far as my programming skills go I can’t seem to find anything that’s wrong with my approach.

var subtree;

$.post("addTreeServlet",
    {
        term:clickedNode,
        max:maxId,
        id:clickedId
    },
    function(jsonResponse){

        subtree = eval('(' + jsonResponse + ')');

    }
);

$jit.json.prune(subtree, level);
return {
     'id': nodeId,
     'children': subtree.children
};

I went through the code with the debugger, and here is what happens: The program comes back from the addTreeServlet and transmits a String representing JSON data. the eval() function takes this String and transforms it into an JSON Object (again, it looks perfectly fine in the debugger). But as soon as I leave the function(jsonResponse) the var subtree is shown as undefined, and I can’t figure out why.

Is that because of the jQuery method? I have no idea…

It is also the same behavior if I just put subtree = “whatever”. It becomes undefined as soon as I exit the function..

Answer 1

It’s waiting for post response, but your fallowing script immediately parsed by browser. So you need to do what you want to do with ajax response after post response received.

function(jsonResponse){
    var subtree = eval('(' + jsonResponse + ')');
    doSomthingWithResponse(subtree);
}