Codeigniter表单验证返回问题

Question

I have making some form validation to my signup. Sofar I can get true or false in my $ajax success function, but cannot get it to returning part to prceed rest of code... Can somebody write a solution to this?

function checkIfIsInDB(o, n){
    var target_url = window.location.pathname + 'user/check_if_username_exist',
    valid = '';        
    $.ajax({
        type: "POST",
        dataType: "json",
        url: target_url,
        data: {
            username: o.val()
        },
        success: 
        function(json){
            if(json['check']===false){
                o.addClass( "ui-state-error" ); 
                updateTips( n + " has been alredy taken." );
            }
            if(json['check']===true){
                valid = true;
            }  
        }

    });
    alert(valid); //return(valid);   need for returning true or false
}

Answer 1

You're working asynchronously, so you need to put your 'proceeding code' in the success: callback part of the $.ajax() function.

You've done it correctly with the failed check, you just need to do the same in the

if(json['check'] ===true){
    //put your success code here - call another function perhaps
}

part.

Answer 2

Try moving the alert() inside the success callback.

function checkIfIsInDB(o, n) {
    var target_url = window.location.pathname + 'user/check_if_username_exist',
        valid = '';
    $.ajax({
        type: "POST",
        dataType: "json",
        url: target_url,
        data: {
            username: o.val()
        },
        success: function (json) {
            if (json['check'] === false) {
                o.addClass("ui-state-error");
                updateTips(n + " has been alredy taken.");
            }
            if (json['check'] === true) {
                valid = true;
            }
            alert(valid); //return(valid);   need for returning true or false
        }

    });

}