README.md

react-suspense-boundary

A boundary component working with suspense and error

Version 2.x is implemented on use-sync-external-store to align with future official suspense data fetching.

Install

npm install react-suspense-boundary

Demo

See online demo here: https://ecomfe.github.io/react-suspense-boundary/

You can start demo app yourself by executing:

npm start

Usage

Basic

import {Boundary, CacheProvider, useResource} from 'react-suspense-boundary';

// Create or import an async function
const fetchInfo = ({id}) => fetch(`/info/${id}`).then(response => response.json());

// Implement your presentational component
function Info({id}) {
    // Call `useResource` to fetch, note the return value is an array
    const [info] = useResource(fetchInfo, {id});

    // There is no `loading` branch, push returned object immediately to render
    return (
        <div>
            {info.id}: {info.name}
        </div>
    );
};

// Data is stored inside `CacheProvider`, suspending state is controlled with `Boundary`
export default function App() => (
    <CacheProvider>
        <Boundary>
            <Info />
        </Boundary>
    </CacheProvider>
);

CacheProvider

CacheProvider is by its name a cache context where we store all resources loaded by its children.

The simpliest way to use CacheProvider is to provider an application level top cache:

import {render} from 'react-dom';
import {CacheProvider} from 'react-suspense-boundary';
import {App} from './components/App';

render(
    <CacheProvider>
        <App />
    </CacheProvider>,
    document.getElementById('root')
);

For some more complex applications, you may want to restrict data caching in a smaller scope, e.g. route level, and expire cached responses on unmount, you can put CacheProvider anywhere you want to make a shared cache.

Boundary

Boundary components defines a boundary in your view, within a boundary all async resource fetchings and errors are collected to form a loading or error indicator.

Usually we would have mulitple Boundary inside a CacheProvider, that is, users see different sections loading individually, but all resources are shared.

A Boundary component receives props below:

interface RenderErrorOptions {
    recover: () => void;
}

interface BoundaryProps {
    // When any of async progress is pending, boundary will render this element
    pendingFallback: ReactNode;
    // When any error are received, will render this function
    renderError(error: Error, options: RenderErrorOptions): ReactNode;
    // When any error are catched, will call this function
    onErrorCaught(error: Error, info: ErrorInfo): void;
}

useResource

The useResource hook is used to inspect an async function within a boundary:

type Resource<T> = [
    T,
    {
        expire(): void;
        refresh(): void;
    }
];

function useResource<I, O>(action: (input: I) => Promise<O>, params: I): Resource<O>;
function useConstantResource<O>(action: () => Promise<O>): Resource<O>;

Unlike other async hooks, useResource returns the result "immediately", there is no pending or loading state, no exception will throw.

Other than the result itself, the second object of useResource's returned array is a a bunch of functions to manually control the cache:

• expire will immediately remove the cached result, causing the upper Boundary to be pending until action is resolved the next time.
• refresh is a function to run action again without removing previously cached result.

Default configuration

BoundaryConfigProvider provides default configurations to pendingFallback, renderError and onErrorCaught props.

import {Spin} from 'antd';
import {BoundaryConfigProvider} from 'react-suspense-boundary';

const defaultPendingFallback = <Spin />;

const defaultRenderError = error => (
    <div>
        {error.message}
    </div>
);

const App = () => {
    <BoundaryConfigProvider
        pendingFallback={defaultPendingFallback}
        renderError={defaultRenderError}
    >
        {/* All Boundary elements inside it receives default configurations */}
    </BoundaryConfigProvider>
}

Preload

Preload is much like resource fetching, they can be "immediately" fired within a render function:

function usePreloadResource<I, O>(action: (input: I) => Promise<O>, params: I): void;
function usePreloadConstantResource<O>(action: () => Promise<O>): void;

Preload fires resource fetching process but not abort current render.

You can also get a preload function using usePreloadCallback hook to preload any resources in effect or event handlers:

const preload = usePreloadCallback();

<Button onMouseEnter={() => preload(fetchList, {pageIndex: currentPageIndex + 1})}>
    Next Page
</Button>

Create Your Own Cache

react-suspense-boundary's built-in CacheProvider references a single context type, that is, you are unable to access multiple caches in a single component:

<CacheProvider>
    <div>
        <CacheProvider>
            <MyResource />
        </CacheProvider>
    </div>
</CacheProvider>

By default, there is no way to a make MyResource to load one resource into the outer CacheProvider and another into the inner CacheProvider.

To solve this issue, we provide a create() function to create a custom set of providers and hooks, with a different context type so that you can use them simultaneously:

import {CacheProvider, create, useConstantResource} from 'react-suspense-boundary';

const {
    CacheProvider: GlobalCacheProvider,
    useConstantResource: useGlobalConstantResource,
} = create();

function MyResource() {
    // Put current user resource into global cache
    const [currentUser] = useGlobalConstantResource(fetchCurrentUser);
    // And other resources into local one
    const [dataSource] = useConstantResource(fetchList);

    return (
        // ...
    );
}

<GlobalCacheProvider>
    <CacheProvider>
        <MyResource />
    </CacheProvider>
</GlobalCacheProvider>

create function also accepts an option object to customize context's display name:

interface CreateOptions {
    cacheContextDisplayName?: string;
    configContextDisplayName?: string;
}