Question

function isNewUsername(str){
    var result;
    $.post('/api/isnewusername', 
            {username:str},
            function(data) {
                result = data.result;
            }, 
            "json");
    return result;
}

So , my problem is very simple but I can not figure it out . I want to access result from the isnewusername function . I am very curious about answer because I spent 1 hour on it .
Thank you

Answer 1

As a quick note when you use the jQuery post function you are using a shorthand form of the jQuery ajax function which means you are doing an asynchronous call. Therefore only on a successful response is jQuery going to call your function and put the result from your server side call in the data parameter of your success callback.

To illustrate:

function isNewUsername(str){
    $.post('/api/isnewusername', 
            {username:str},
            function(data) {
                alert(data.result);
            }, 
            "json");
}

That said you can change your code to specify a synchronous callback but that has the potential to lock the users browser until the request is returned.