# Optimisation for repeat.for (or sorting) with list

**URL:** <https://discourse.aurelia.io/t/optimisation-for-repeat-for-or-sorting-with-list/4861>\
**Category:** Help Requests\
**Created:** [July 27, 2022, 3:12pm UTC](https://discourse.aurelia.io/t/optimisation-for-repeat-for-or-sorting-with-list/4861 "2022-07-27T15:12:25Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![sarp](https://avatars.discourse-cdn.com/v4/letter/s/ad7895/32.png) [@sarp](https://discourse.aurelia.io/u/sarp)\
**Post date:** [July 27, 2022, 3:12pm UTC](https://discourse.aurelia.io/t/optimisation-for-repeat-for-or-sorting-with-list/4861/1 "2022-07-27T15:12:25Z")

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Hey people.

At the moment I have a list of divs, being generated with repeat.for and contain significant level of children. Enough, so that I don’t want to keep re-rendering the entire node.

```auto
<div class="table-row" repeat.for="row of rows">
...lots of children...
</div>

```

User selects a key and list gets sorted by that key. For this, I use a getter function to keep the original data untouched (although the issue is still there, even without the this approach).

Despite no new `table-row` being inserted, and all that is needed is a simple re-order, repeat.for rebuilds everything from bottom up, as far as I observe (constructors are being called etc.). Are there any approaches I can employ here to prevent that from happening? Something like FlatList from react-native if that makes sense, where list items have unique, persistent keys and it prevents the need for constant re-renders. At the moment, as is, repeat.for is too expensive, despite being very intuitive to use.

Edit:

I think this issue perfectly describes the issue I am explaining: [Repeat.for to support key (custom resolution strategy) · Issue #1264 · aurelia/aurelia · GitHub](https://github.com/aurelia/aurelia/issues/1264)

The issue offers a workaround, which works, but it kills the opportunity to use a good feature like getter functions or other JS features like spread.