ganarajpr/angular-dragdrop — pull request #106 by paulpach (2014-12-01 19:23:03+00:00)
Title: Evaluate drag expression only when drag starts.

This change makes it so the drag expression is evaluated only once when
the dragging start, instead of $watching it.
This way, I can use expressions such as
drag="[myobj]"
drag="something + other"
That create an object every time they are evaluated.

This also means a performance win, since $watching is very expensive,
and completely unnecessary when the user is not doing drag and drop.