Undefined return value in JQuery

Question

This function returns an undefined value when it is executed. I want it to return true if the page is loaded and false if not:

function JLoad (url) {
        var uri = url + ' #div';
        $("#div").load(uri, {'bd': '1'}, function(response, status, xhr){
            if (status != "error"){
                if (window.history && window.history.pushState)
                {
                    window.history.pushState({}, 'Test', url);
                }
                else
                {
                    window.location.hash='!/'+url;
                }
                return true;
            }else{
                return false;
            }
        });
    };

This is part of the code used to request the function:

$(document).ready(function() {
$("a").on("click", function() {
        var url = $(this).attr("href").replace('./', '');
    console.log(JLoad(url));
        return false;
    });
});

The method load is Asynchronous, you can not return a value from the callback! — epascarello
– epascarello, Commented Jun 6, 2013 at 19:26
@epascarello, could i replace the returns with something like "returnVal = true" and the put "return returnVal" at the end of the function? — Blease
– Blease, Commented Jun 6, 2013 at 19:28
What are you trying to accomplish with the returned Boolean. Based on that we can give you an answer that will help out. — epascarello
– epascarello, Commented Jun 6, 2013 at 19:31
@epascarello I wish to apply a selected class to the link if the content is successfully loaded, with this code: if(JLoad(url)){ $("a").removeClass("active");$(this).addClass("active");} — Blease
– Blease, Commented Jun 6, 2013 at 19:33

Joe · Accepted Answer · 2013-06-06 19:39:41Z

3

Because jQuery.load() is asynchronous, rewrite your function to accept a callback.

function JLoad (url, cb) {
    var uri = url + ' #div'
    $("#div").load(uri, {'bd': '1'}, function(response, status, xhr){
        if (status != "error"){
            if (window.history && window.history.pushState)
            {
                window.history.pushState({}, 'Test', url);
            }
            else
            {
                window.location.hash='!/'+url;
            }
            cb(true);
        } else{
            cb(false);
        }
    });
}

Then:

$(document).ready(function() {
    $("a").on("click", function() {
        var $link = $(this),
            url = $link.attr("href").replace('./', '');

        JLoad(url, function(successful) {
            if (successful) {
                $("a").removeClass("active");
                $link.addClass("active");
            }
        });
    });
});

edited Jun 6, 2013 at 19:39

answered Jun 6, 2013 at 19:33

Joe

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1 Comment

Blease Over a year ago

I was just about to say, I had to add "var $link = $(this);". But thank you so much for your help!

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