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30-seconds-of-code/snippets/useFetch.md
Isabelle Viktoria Maciohsek 790f0de37f Update formatting
2022-01-30 19:40:51 +02:00

1.3 KiB

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title tags firstSeen lastUpdated
useFetch hooks,effect,state,intermediate 2019-08-21T14:23:57+03:00 2021-01-07T23:57:13+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 and error state variables.
  • Use the useEffect() hook to asynchronously call fetch() and update the state variables accordingly.
  • Return an object containing the response and error state variables.
const useFetch = (url, options) => {
  const [response, setResponse] = React.useState(null);
  const [error, setError] = React.useState(null);

  React.useEffect(() => {
    const fetchData = async () => {
      try {
        const res = await fetch(url, options);
        const json = await res.json();
        setResponse(json);
      } catch (error) {
        setError(error);
      }
    };
    fetchData();
  }, []);

  return { response, error };
};
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.render(<ImageFetch />, document.getElementById('root'));