Pull revert Or Limit number of items

[LukeTOBrien]

Hello chaps.

I Have two containers, A and B, containers B is empty and I want to choose one item from container A and drag it inside.
Container B can only have one item inside, so therefore I either want to swap the item being dragged with the item already in the container or I want to revert on pull so that no item is dragged into container B but the onEnd event still fires.

I am using a framework which means that the text of container B is bound to the object I am creating, so I don't need the dragged item to stay in place.
So in my lil app I am creating an appointment, I have a list of doctors and a list of patients, and the appointment with a placeholder for each, but when I drag I can keep on adding to the placeholders.

I can create a CodePen if that will help illustrate.

Thanks

[waynevanson]

You might be able to use onMove on Container A option to your advantage.
When dragging an item to container B, you need to check if it's container B and if >= 1 elements exist, return false from the onMove function.

That will mean that the item will not move to Container B and it will work as you please.

[LukeTOBrien]

This is what I did in the end:
So you can only drag onto an empty list.

put: function(to) {
  return to.el.children.length == 0;
}