Snap.svg - drag event handler

Question

Question is about the onstart event handler for Element.drag in the newly announced Snap.svg.

The intention of the code below is to register event handlers for the start

Answer 1

After struggling for some hours to do this with snap.js, I finally discovered svg.js and its draggable plugin, with which it is so much easier:

var draw = SVG('svg');
var circle = draw.circle(10).attr({cx:30,cy:30,fill:'#f06'});
circle.dragend = function(delta, event) {
    alert(this.attr('cx'))
}
circle.draggable();

So, I switched to svg.js ...