react-fast-fetch

Fetch and cache remote data in React apps. Make your app load faster.

react-fast-fetch is a stale-while-revalidate implementation similiar to swr, with optimized support for IndexedDB.

Install

npm install --save react-fast-fetch

Example

Basic

Use default fetch and MemoryStore.

import { useFetch } from 'react-fast-fetch';

function App() {
  const { data, loading, reload, error } = useFetch('https://unpkg.com/react/package.json');

  return (
    <div>
      {loading ? (
        <span>Loading...</span>
      ) : (
        <>
          {error ? (
            <span>Failed to fetch data</span>
          ) : (
            <span> Latest version of React is {data?.version}</span>
          )}
          &nbsp;
          <button onClick={reload}>Reload</button>
        </>
      )}
    </div>
  );
}

render(<App />);

Choose a store

react-fast-fetch supports 5 types of storage:

• If you want to persist your data and share between tabs:
  • For large site with many APIs and huge amount of data, use IndexedDBStore
  • For small site with only a few APIs, use StorageStore (localStorage)
• If you want to persist data between page refreshing and avoid sharing data between tabs, use StorageStore (sessionStorage)
• If you don't want to persist your data, use MemoryStore

You can also use multiple different store in the same app, if you know what you really need!

MemoryStore

import { MemoryStore } from 'react-fast-fetch';

export const store = new MemoryStore({
  // maximum 2000 url to cache
  limit: 2000,
});

StorageStore

import { StorageStore } from 'react-fast-fetch';

export const store = new StorageStore({
  // or sessionStorage as you want
  storage: localStorage,
  // maximum 500 url to cache
  limit: 500,
});

IndexedDBStore

import { IndexedDBStore } from 'react-fast-fetch';

export const store = new IndexedDBStore({
  // database name
  dbName: 'my-store',
  // maximum 5000 url to cache
  limit: 5000,
});

Write a fetcher

fetch

const fetcher = (url) => fetch(url).then((res) => res.json());

axios

import axios from 'axios';

const fetcher = (url) => axios.get(url).then((res) => res.data);

useFetch hook

Config

Here are two ways to configure react-fast-fetch.

// Use global config, recommended
<FetchProvider fetcher={fetcher} store={store}>
  ...
</FetchProvider>;

// Use local config, for flexibility
const { data } = useFetch('/url', { fetcher: customFetcher, store: customStore });

Both ways supports the following configuration:

Options

disabled

Disable data fetching. This is useful when some parameters is required to fetch data.

const [page, setPage] = useState(1);
const { data } = useFetch(`/posts?page=${page}`, { disabled: page < 1 });

preserve

When url or params changes, preserve old data before new data loaded. Enable when you want smooth transition. However, old data may cause displaying wrong information. Use it carefully.

Typical usage example may want to enable this option:

• Fetch list of data and change page number.
• Update dropdown menu while changing search keyword.

interval

Auto-reload data in N milliseconds. Use it to keep data up-to-date.

const { data } = useFetch(`/notifications/unread`, { interval: 5000 });

onLoad

Callback when the intial load is done.

const [page, setPage] = useState(1);
const { data } = useFetch(`/posts?page=${page}`, {
  onLoad: (url, data) => {
    console.log(url, data);
  },
});

onReload

Callback when data is reloaded.

const [page, setPage] = useState(1);
const { data } = useFetch(`/posts?page=${page}`, {
  onReload: (url, data) => {
    console.log(url, data);
  },
});

Return

data

Result data returned by fetcher.

const { data } = useFetch('/posts/1');

loading

If here is NO cached data and fetcher is fetching data from remote, loading is set to true.

const { data, loading } = useFetch('/posts/1');
return (
  <div>
    {loading && <div>Loading...</div>}
    {data && <div>{data.title}</div>}
  </div>
);

reloading

If here is cached data and fetcher is fetching data from remote, reloading is set to true. In most cases, you don't need to notice user that it is reloading if the API is fast enough. If the API is indeed very slow, show some messages or progress bars that don't block user interaction.

const { data, loading } = useFetch('/posts/1');
return (
  <div>
    {loading && <div>Loading...</div>}
    {reloading && <div>Refreshing...</div>}
    {data && <div>{data.title}</div>}
  </div>
);

reload

A function to manually reload data from remote. Usually used in two cases:

1. Automatic fetch failed. See error section bellow.
2. You modified the resource. For example, you delete a post and then you need to reload the list.

error

Error throwed by fetcher. Usually mean user need to reload the data.

const { data, loading } = useFetch('/posts/1');
return (
  <div>
    {loading && <div>Loading...</div>}
    {error && (
      <span>
        Failed to fetch data <button onClick={reload}>Reload</button>
      </span>
    )}
    {data && <div>{data.title}</div>}
  </div>
);