Edit in JSFiddle

<button id="btn1" class="btn btn-primary ladda-button" data-style="expand-left">
    <span class="ladda-label">button</span>
</button>

$(function () {
    $("#btn1").click(function () {
        var obj = Ladda.create(this);
        obj.start();
        setTimeout(function () {
            obj.stop();
        }, 1000);
    });
});