Feature request: keep previous data

[mrfratello]

There are not enough "keep previous data" feature - return the previous key's data until the new data has been loaded.

This feature is well explained in swr: https://swr.vercel.app/docs/advanced/understanding#return-previous-data-for-better-ux

There is an example on @nanostores /query: https://codesandbox.io/p/sandbox/nanostories-query-react-paging-rick-morty-q6ctwm

It shows how the content "jumps" when the user navigates to the next page (when the cache is empty).

[dkzlv]

@mrfratello Hey there!

Great suggestion. I think it may be of some use in the core, indeed. I'll think about adding it there in the upcoming release.

In the meantime I'll just say that it's fairly straightforward to implement in userland (even in the form of a reusable utility). Here's a simple implementation. I may have missed something there (e.g., data will be there even if error shows up which I'm not sure is the right call), but it seems quite stable to me.

[mrfratello]

Thanks for the example. Unfortunately, it looks like rocket science to me.

I have dragged this example into my project and it works as should.

But, I will wait for the implementation of this feature in the core.