jQuery UI slider 'change' event fires even when value has not changed

SexyBeast picture SexyBeast · Mar 19, 2013 · Viewed 45k times · Source

I am trying to fire an event when a user slides the slider and the value is changed when the sliding stops. As per the jQuery docs, the changeevent would be ideal for this case. So I am trying this out:

<!doctype html>
    <html lang="en">
        <head>
            <meta charset="utf-8" />
            <title>jQuery UI Slider - Default functionality</title>
            <link rel="stylesheet" href="http://code.jquery.com/ui/1.10.2/themes/smoothness/jquery-ui.css" />
            <script src="http://code.jquery.com/jquery-1.9.1.js"></script>
            <script src="http://code.jquery.com/ui/1.10.2/jquery-ui.js"></script>
            <link rel="stylesheet" href="/resources/demos/style.css" />
            <script>
                $(function() {
                    $( "#slider" ).slider({
                        change:function() { alert("foo"); }
                    });
                });
            </script>
        </head>
        <body>
            <div id="slider"></div>
        </body>
    </html>

However, I observe that when I drag the slider to the right and again drag it back to the starting point (the initial position of the slider at page-load), the alert still fires. Is this a jQuery bug? If no, how do I fix this?

Answer

isherwood picture isherwood · Mar 19, 2013
$(function() {
    $("#slider").slider();

    var startPos = $("#slider").slider("value");, 
        endPos = '';

    $("#slider").on("slidestop", function(event, ui) {
        endPos = ui.value;

        if (startPos != endPos) {
            // do stuff
        }

        startPos = endPos;
    });
});