fix(core): Prevent leave animations on a move operation#63745
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thePunderWoman wants to merge 1 commit intoangular:mainfrom
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fix(core): Prevent leave animations on a move operation#63745thePunderWoman wants to merge 1 commit intoangular:mainfrom
thePunderWoman wants to merge 1 commit intoangular:mainfrom
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AndrewKushnir
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When a user has `animate.leave` on a list of items in a `@for`, but are only showing a subset using a computed, removing the second to last item results in a move operation on the last item. There's no native atomic move API in the browser. So this results in the element being detached and attached at its new index. The detaching of the node resulted in leave animations firing. This fix addresses this by adding a flag in the `LView[ANIMATIONS]` `AnimationLViewData` interface to allow for skipping animations. During list reconciliation, we set this flag so that the animations are skipped over. The flag is flipped back after the move operation is complete. There is one complication that results from this. The index adjustment of elements in the list happens synchronously while the leave animation is asynchronous. This results in the leaving item getting shifted to the end of the list. This is not ideal but likely can be addressed in a future refactor. fixes: angular#63544
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thePunderWoman
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When a user has `animate.leave` on a list of items in a `@for`, but are only showing a subset using a computed, removing the second to last item results in a move operation on the last item. There's no native atomic move API in the browser. So this results in the element being detached and attached at its new index. The detaching of the node resulted in leave animations firing. This fix addresses this by adding a flag in the `LView[ANIMATIONS]` `AnimationLViewData` interface to allow for skipping animations. During list reconciliation, we set this flag so that the animations are skipped over. The flag is flipped back after the move operation is complete. There is one complication that results from this. The index adjustment of elements in the list happens synchronously while the leave animation is asynchronous. This results in the leaving item getting shifted to the end of the list. This is not ideal but likely can be addressed in a future refactor. fixes: #63544 PR Close #63745
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wildcardalice
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Sep 18, 2025
When a user has `animate.leave` on a list of items in a `@for`, but are only showing a subset using a computed, removing the second to last item results in a move operation on the last item. There's no native atomic move API in the browser. So this results in the element being detached and attached at its new index. The detaching of the node resulted in leave animations firing. This fix addresses this by adding a flag in the `LView[ANIMATIONS]` `AnimationLViewData` interface to allow for skipping animations. During list reconciliation, we set this flag so that the animations are skipped over. The flag is flipped back after the move operation is complete. There is one complication that results from this. The index adjustment of elements in the list happens synchronously while the leave animation is asynchronous. This results in the leaving item getting shifted to the end of the list. This is not ideal but likely can be addressed in a future refactor. fixes: angular#63544 PR Close angular#63745
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When a user has
animate.leaveon a list of items in a@for, but are only showing a subset using a computed, removing the second to last item results in a move operation on the last item. There's no native atomic move API in the browser. So this results in the element being detached and attached at its new index. The detaching of the node resulted in leave animations firing. This fix addresses this by adding a flag in theLView[ANIMATIONS]AnimationLViewDatainterface to allow for skipping animations. During list reconciliation, we set this flag so that the animations are skipped over. The flag is flipped back after the move operation is complete.There is one complication that results from this. The index adjustment of elements in the list happens synchronously while the leave animation is asynchronous. This results in the leaving item getting shifted to the end of the list. This is not ideal but likely can be addressed in a future refactor.
Screen.Recording.2025-09-11.at.1.53.21.PM.mov
fixes: #63544