abort-controller.js

function useAbortController() {
  const abortControllerRef = React.useRef()
  const getAbortController = React.useCallback(() => {
    if (!abortControllerRef.current) {
      abortControllerRef.current = new AbortController()
    }
    return abortControllerRef.current
  }, [])

  React.useEffect(() => {
    return () => getAbortController().abort()
  }, [getAbortController])

  const getSignal = React.useCallback(() => getAbortController().signal, [
    getAbortController,
  ])

  return getSignal
}

Thank you for engaging with me on this random piece of discussion.

The original code still creates an AbortController, even if it's never "used", for the useEffect cleanup.

Removing the callback, and the unintended instantiation, this seems slightly less readable but functionally more fitting to presumed intention, with no loose ends.

function useAbortController() {
  const abortControllerRef = React.useRef<AbortController>()

  React.useEffect(() => {
    return () => abortControllerRef.current?.abort()
  }, [])

  const getSignal = React.useCallback(() => {
    if (!abortControllerRef.current) {
      abortControllerRef.current = new AbortController()
    }
    return abortControllerRef.current.signal
  }, [])

  return getSignal
}

Solid 👍👍

Hello folks, could someone kindly show me how this works in practise?

I'm currently doing this with a ref, this looks more elegant though

Whoever found above gist first before Kent's own tweet, use the above hook like below. Directly copied from that tweet.

const getSignal = useAbortController()

// in an effect
fetch('/thing', {signal: getSignal()})

I use it this way, but it raises error: Failed to execute 'fetch' on 'Window': The user aborted a request.

  const getSignal = useAbortController();
  const [data, setData] = useState();

  const doFetch = async () => {
    const signal = getSignal();
    const response = await fetch("https://codesandbox.io", { signal });
    const result = await response.body;

    setData(result);
  };

  useEffect(() => {
    doFetch()
  }, []);

How to solve?

How do you manually call abort() from this?

Here is my manually controlled abortController I use to allow users to cancel an upload in React Native

function useAbortController() {
  const abortControllerRef = useRef();
  const getAbortController = useCallback(() => {
    console.log('getAbortController', abortControllerRef.current);
    if (!abortControllerRef.current) {
      abortControllerRef.current = new AbortController();
    }
    return abortControllerRef.current;
  }, []);

  const abortSignal = useCallback(() => {
    if (abortControllerRef.current) {
      abortControllerRef.current.abort();
 
      abortControllerRef.current = null;      // Resets it for next time
    }
  }, []);

  const getSignal = useCallback(
    () => getAbortController().signal,
    [getAbortController]
  );

  return { getSignal, abortSignal };
}

Inspired by @charlestbell

• Leave control to the user of the hook to abort() anytime they want, not just on unmount.
• Returns a (memoized) object that resembles the AbortController API: { abort, signal } instead of the getSignal function.
• Strict null checks on abortCtrlRef.current instead of falsey for perf (just because).

function useAbortController() {

  const abortCtrlRef = useRef( null );

  const getAbortController = useCallback(
    () => {
      if ( abortCtrlRef.current === null ) abortCtrlRef.current = new AbortController();
      return abortCtrlRef.current;
    },
    []
  );

  const abort = useCallback(
    () => {
      if ( abortCtrlRef.current !== null ) {
        abortCtrlRef.current.abort();
        abortCtrlRef.current = null;
      }
    },
    []
  );

  return useMemo(
    () => ({
      get signal() { return getAbortController().signal; },
      abort,
    }),
    [ getAbortController, abort ]
  );

}

Usage:

function MyComponent( props ) {

  // { abort, signal } just like a real AbortController
  const { abort, signal } = useAbortController();

  // Some useEffect or other thing you need to be able to abort
  useEffect(() => fetch( url, { signal } ), [ signal ]);

  // The user of the hook can abort whenever they please.
  useEffect(() => () => abort(), [ abort ]);

}

Ia had same implementation in typescript. Only difference if that I'm aborting with reason. I mostly use this in cases when I need to stop a flow on re-render.

import React from "react"

export function useAbortController() {
  const abortControllerRef = React.useRef<AbortController | undefined>()

  const getAbortController = React.useCallback(() => {
    abortControllerRef.current =
      abortControllerRef.current && !abortControllerRef.current.signal.aborted
        ? abortControllerRef.current
        : new AbortController()
    return abortControllerRef.current
  }, [])

  const getSignal = React.useCallback(() => {
    return getAbortController().signal
  }, [getAbortController])

  React.useEffect(() => {
    return () => {
      getAbortController().abort("Re-render")
    }
  }, [getAbortController])

  return getSignal
}