transform() option

[rentalhost]

I have a use case where I need to transform the data received by the fetcher before it is delivered by the SWR. Well, I could do it in the fetcher itself, but since my fetcher is so simple, I can reuse it in many places, whereas a transform() is exceptional.

In my case, the data that I get from the server is disorganized, and I want to keep it in alphabetical order. So I needed to use SWR and do an intermediary useMemo() for that, however, I have two copies of pretty much the same information.

Currently:

const { data: dataOriginal } = useSWR(url, fetcher);
const data = useMemo(() => reorder(dataOriginal), [dataOriginal]);

Possible solution modifying fetcher: but in this case, I need to maintain several fetchers or generate greater complexity in them for something that I think would be essential to be the responsibility of the SWR.

const { data } = useSWR(url, customFetcher);

Feature request:

const { data } = useSWR(url, fetcher, {
    transform: (data) => reorder(data)
});

[wesrog]

Have you looked into middleware yet? https://swr.vercel.app/docs/middleware

From the docs:

Middleware receive the SWR hook and can execute logic before and after running it.

Perhaps you can do your transformation in the "before" state as it mentions?

[rentalhost]

Hm... Middleware might work, but I believe it makes the process much more complex than what I did (useMemo) and what would be ideal (transform). Another possibility would be to create a "fetcher factory", which might be my next attempt. And perform the transformation within it before send to SWR. Despite everything, it seems to me a compatible idea that SWR has some data transformation capability.