30-seconds-of-code/snippets/useFetch.md

title, tags, author, cover, firstSeen, lastUpdated

title	tags	author	cover	firstSeen	lastUpdated
React useFetch hook	hooks,effect,state	chalarangelo	coworking-space	2019-08-21T14:23:57+03:00	2022-05-01T12:50:38+02:00

Implements fetch() in a declarative manner.

• Create a custom hook that takes a url and options.
• Use the useState() hook to initialize the response, error and abort state variables.
• Use the useEffect() hook to asynchronously call fetch() and update the state variables accordingly.
• Create and use an AbortController to allow aborting the request. Use it to cancel the request when the component unmounts.
• Return an object containing the response, error and abort state variables.

const useFetch = (url, options) => {
  const [response, setResponse] = React.useState(null);
  const [error, setError] = React.useState(null);
  const [abort, setAbort] = React.useState(() => {});

  React.useEffect(() => {
    const fetchData = async () => {
      try {
        const abortController = new AbortController();
        const signal = abortController.signal;
        setAbort(abortController.abort);
        const res = await fetch(url, {...options, signal});
        const json = await res.json();
        setResponse(json);
      } catch (error) {
        setError(error);
      }
    };
    fetchData();
    return () => {
      abort();
    }
  }, []);

  return { response, error, abort };
};

const ImageFetch = props => {
  const res = useFetch('https://dog.ceo/api/breeds/image/random', {});
  if (!res.response) {
    return <div>Loading...</div>;
  }
  const imageUrl = res.response.message;
  return (
    <div>
      <img src={imageUrl} alt="avatar" width={400} height="auto" />
    </div>
  );
};

ReactDOM.createRoot(document.getElementById('root')).render(
  <ImageFetch />
);