How to cancel an HTML5 drag (and drop) operation using Javascript?

Question

I want to cancel an HTML5 drag operation based on some condition. I have tried to search this but found nothing useful. It seems that there is no way to cancel an HTML5 drag and drop using JavaScript. returning false in the dragstart doesn't seem to do anything. Any ideas?

Answer 1

You can cancel it by calling event.preventDefault() in the event handler. For example this should work:

<p id="p1" draggable="true" ondragstart="dragstart_handler(event);">This element is draggable.</p>

<script>
var enableDragDrop = true;
function dragstart_handler(ev) {
    if (!enableDragDrop) {
        ev.preventDefault();
    }
    console.log("dragStart");
}
</script>