Popmotion pose holds on to and animates orphan DOM elements

[aholachek]

Hi, I used react-pose for an animation demo and came across these problems:

1. Shuffling children leads to an out-of-order staggered exit transition for children
2. Specifying a "preEnterPose" removes the children's staggered enter animations completely.
3. The "preEnterPose" is only active the first time the parent element is animated in.
4. Most seriously, when re-animating the parent element in, DOM elements that do not correspond to anything in the props array are animated in (there should only be 8 cards in this image):

You should be able to reproduce by checking out the demo posted above, and my code is here

In case it's helpful, an example demonstrating expected behavior is here

Hopefully these issues are a result of my own user error, if so, sorry for making an issue!

[mattgperry]

Thanks for the detailed explanation and code example!

1. Know what's the cause and made a ticket here: Reorder Pose children #319
2. Did you try setting a state on the children items with the same "preEnterPose"?
3. I think this is by design? It's like ReactTransitionGroup's appear state - a way of setting an animation when the PoseGroup first appears rather than subsequent entries. Could probbly communicate this better, unless you mean something else.
4. Old DOM items are kept in PoseGroup #320

[aholachek]

2. I added a preEnterPose to the child PoseGroup and it is working exactly as expected. I guess I thought in this case the children would default to using the exit pose to preload values if no preEnterPose was specified.
3. You're right, it's totally working correctly.

Thanks for making this library, btw, it's really cool how it's both powerful and user-friendly.