CODEWITHSUNDEEP
javascriptjquery
Yemto
Yemto

Reputation: 613

Javascript ignores true and false

This should really be simple. But the code I'm trying to write is just not working, even after searing around the internet.

So I have this. code to check if a user is online or offline.

//Check if it's a valid user
function checkUser(){
status = (function(){
    var isOnline = null;
    $.ajax({
        async: false,
        global: false,
        type: "POST",
        url: "./system/checkUser.php",
        data: $("#webcam").serialize(),
        success: function(data){
            isOnline = (data == "1");
        }
    });
    return isOnline;
})();

return status;
}

and this is how I try to use it

function loadProfile(){
var text = checkUser();
alert(text);

if(text != true){
    alert("Invalid user!");
    return;
}else{
    //Code
}

But whatever I get from checkUser(), I always get the "Invalid user!" alert, even when text is true. Can anyone help me here? I'm lost for words.

Upvotes: 0

Views: 101

Answers (2)

jcarpenter2
jcarpenter2

Reputation: 5476

async: false is deprecated so you have to use a callback to access data from an ajax request.

You could change your checkUser function so that it takes a success callback as a parameter.

I personally don't like using big callbacks, so I usually get around the problem with a $.Deferred:

function checkUser() {

    status = $.Deferred();

    $.ajax({
        global: false,
        type: "POST",
        url: "./system/checkUser.php",
        data: $("#webcam").serialize(),
        success: function(data) {
            status.resolve(data == "1");
        }
    });

    return status;
}

function loadProfile() {

    var textD = checkUser();

    textD.done(function (text) {
        alert(text);

        if(text != true){
            alert("Invalid user!");
        }
    });
}

Upvotes: 1

Derek 朕會功夫
Derek 朕會功夫

Reputation: 94409

As of jQuery 1.8, the use of async: false with jqXHR ($.Deferred) is deprecated; you must use the success/error/complete callback options instead of the corresponding methods of the jqXHR object such as jqXHR.done() or the deprecated jqXHR.success().

http://api.jquery.com/jquery.ajax/

What you can do is:

function checkUser(callback){
    $.ajax({
        global: false,
        type: "POST",
        url: "./system/checkUser.php",
        data: $("#webcam").serialize(),
        success: callback
    })
}

function loadProfile(){
    checkUser(function(text){
        alert(text);

        if(text != true){
            alert("Invalid user!");
            return;
        }else{
            //Code
        }
    });
}

Upvotes: 3

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