On: Virtual DOM is pure overhead (2018)

[vbezhenar]

For example HTTP request. Anything, actually. Some rough code:

    function Item({id}) {
      const r = usePromise(async (signal) => {
          const resp = await fetch(`/item/${id}`, {signal});
          return await resp.json();
      }, [id]);
      if (r.status == "pending") {
        return <div>Loading</div>;
      }
      if (r.status == "rejected") {
        return <div>Error: {r.reason}</div>;
      }
      return <div>{r.value}</div>;
    }

It's really like useEffect but provides better support for cancellation and properly tracks promise. Rewriting this snippet with useEffect correctly would require quite a lot of code (although rewriting this snippet with useEffect incorrectly is possible with not a lot of code, but you don't want to write incorrect code). Which has to be repeated everywhere.

Again, this task is better solved by react-query or its alternatives. What I'm writing is not strictly web-site, but rather a web-interface on embedded device and web-server is not remote web-server but thing that works on the same device, so for now I decided not to use those libraries which made for slightly different use-cases.

[scotty79 → vbezhenar]

I think I'd go about it using redux-thunk because I feel like render function is not a great place for complex async state changes and chcecking internal status of a promise is a bit low level, but you've built a nice, easy to use thing. If you published it some people might find it to be exactly what they need. Plus they might help you debug some corner cases.

[acemarke → scotty79]

FYI, we recommend that most folks should not write promise management, data fetching, or loading status tracking code directly

If you're using just React, use React Query or something like `react-async`.

If you're using Redux, use the "RTK Query" data fetching and caching API in our official Redux Toolkit package:

- https://redux.js.org/usage/side-effects-approaches

[vbezhenar → scotty79]

Thanks, I'll think about it.