PoppingPopper•3y ago

setInterval without destroying it to update state?

I have a perdicament where I want to update state on an interval. Every way that I go about it I find myself being forced to use the dependency array of the useEffect for the setInterval so I can get updated state values. This causes my interval to just be destroyed and rebuilt every interval because of state changing on the interval. How can I achieve this interval without ever having to destroy it to listen to state changes?

  const [incrementCount, setIncrementCount] = useState(1);
  const [translationX, setTranslationX] = useState([...INIT_TRANSLATION_X]);

  const incrementTranslationX = useCallback(() => {
    if (incrementCount && incrementCount % 2 === 0) { //* the condition
      setIncrementCount(0);
      setTranslationX([...INIT_TRANSLATION_X]);
    } else {
      setIncrementCount((prev) => prev + 1);
      setTranslationX((prev) => [prev[0] + INCREMENT, prev[1] + INCREMENT]);
    }
  }, [incrementCount, translationX]);

  //loop interval
  useEffect(() => {
    const interval = setInterval(() => {
      incrementTranslationX();
    }, INTERVAL);

    return () => {
      clearInterval(interval);
      console.log("DESTROYED INTERVAL");
    };
  }, [incrementTranslationX]); //! cannot update (the condition) without this

  const [incrementCount, setIncrementCount] = useState(1);
  const [translationX, setTranslationX] = useState([...INIT_TRANSLATION_X]);

  const incrementTranslationX = useCallback(() => {
    if (incrementCount && incrementCount % 2 === 0) { //* the condition
      setIncrementCount(0);
      setTranslationX([...INIT_TRANSLATION_X]);
    } else {
      setIncrementCount((prev) => prev + 1);
      setTranslationX((prev) => [prev[0] + INCREMENT, prev[1] + INCREMENT]);
    }
  }, [incrementCount, translationX]);

  //loop interval
  useEffect(() => {
    const interval = setInterval(() => {
      incrementTranslationX();
    }, INTERVAL);

    return () => {
      clearInterval(interval);
      console.log("DESTROYED INTERVAL");
    };
  }, [incrementTranslationX]); //! cannot update (the condition) without this

Solution:

Looks like the answer I'm looking for is to not read state at all and instead use local values.

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2 Replies

Solution

PoppingPopper•3y ago

Looks like the answer I'm looking for is to not read state at all and instead use local values.

aprillion•3y ago

or read someRef.current from inside an interval