[Glimmer] ContainerView issue?

[amk221]

I'm not sure how best to describe this issue I'm experiencing, so I made two fiddles to demonstrate it:

1.12.0-beta.3: http://jsfiddle.net/amk221/dqf7qvzo/
1.13.0-beta.1: http://jsfiddle.net/amk221/1ecd458q/

I think what is happening is: The new ContainerView hbs template loops through its views using the each helper, re-rending them. This is causing the CSS animations to fire each time, when previously (pre-Glimmer) it did not.

[krisselden]

@amk221 you can solve by giving each a key prop that means the row should be stable with that key. Bonus this works if the underlying array is a new array but where the elements have been rendered before.

@wycats a default item key of index would at least match prior behavior for when the underlying array was stable and you pushed onto it.

[amk221]

@krisselden Is this what you mean. It already has a key of elementId

[krisselden]

@amk221 sorry, I missed that, it does loop through each time but it shouldn't be recreating dom if the key is stable.

[amk221]

@rwjblue Might this have been fixed by the recent work on each key ? #11337

[rwjblue]

@amk221 - It is certainly possible, would you mind confirming with an updated JSFiddle/JSBin?

[amk221]

I just swapped the URLs for canary in the above fiddles, yes - issue has gone

[rwjblue]

Awesome! Thank you!