onUnmounted property

[jh3141]

I have a component with a list of Swipeable items. I track a currently active item by storing the reference that is passed to my onRightButtonsActivate handler. I then use this reference to call recenter if a different item activates. This works well, but I get a warning about illegal calls to setState if the item is removed from the list -- it would be useful if I could get a notification about unmounted Swipeables so that I can delete any references I hold to them.