52 lines
1.3 KiB
Markdown
52 lines
1.3 KiB
Markdown
---
|
|
title: useFetch
|
|
tags: hooks,effect,state,intermediate
|
|
---
|
|
|
|
A hook that implements `fetch` in a declarative manner.
|
|
|
|
- Create a custom hook that takes a `url` and `options`.
|
|
- Use the `React.useState()` hook to initialize the `response` and `error` state variables.
|
|
- Use the `React.useEffect()` hook to anychronously call `fetch()` and update the state varaibles accordingly.
|
|
- Return an object containting the `response` and `error` state variables.
|
|
|
|
```jsx
|
|
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 };
|
|
};
|
|
```
|
|
|
|
```jsx
|
|
const ImageFetch = props => {
|
|
const res = useFetch('https://dog.ceo/api/breeds/image/random', {});
|
|
if (!res.response) {
|
|
return <div>Loading...</div>;
|
|
}
|
|
const dogName = res.response.status;
|
|
const imageUrl = res.response.message;
|
|
return (
|
|
<div>
|
|
<img src={imageUrl} alt="avatar" width={400} height="auto" />
|
|
</div>
|
|
);
|
|
};
|
|
|
|
ReactDOM.render(<ImageFetch />, document.getElementById('root'));
|
|
```
|