Question

I have the following code which will allowed a user running iOS to move a <div> with the class .drag around on the page. This works fine when there is one istance of .drag, but fails to work when there are two instances of it. Is it possible to have the code find all of the <div>‘s, then allow them to be draggable?

var drag = $(".drag")[0];
    xPos = drag.offsetWidth / 2;
    yPos = drag.offsetHeight / 2;
    drag.addEventListener("touchmove", function() {
        event.preventDefault();
        $(this).css({
        'left' : event.targetTouches[0].pageX - xPos + 'px', 
        'top' : event.targetTouches[0].pageY - yPos + 'px'
    });
});

Answer 1

When you use $(selector)[0], you get the first DOM element that matches the selector. Use .each() instead to add the event listener to all elements that match the selector:

$(".drag").each(function () {
    var drag = this;
    xPos = drag.offsetWidth / 2;
    yPos = drag.offsetHeight / 2;
    drag.addEventListener("touchmove", function() {
        event.preventDefault();
        $(this).css({
          'left' : event.targetTouches[0].pageX - xPos + 'px', 
          'top' : event.targetTouches[0].pageY - yPos + 'px'
        });
    });
});​