useLive()

Async rendering of remotely triggered data mutations.

useSuspense() + useSubscription() in one hook.

useLive() is reactive to data mutations; rerendering only when necessary.

Usage

Ticker

AssetPrice

import { useLive } from '@data-client/react';
import { getTicker } from './Ticker';

function AssetPrice({ productId }: Props) {
  const ticker = useLive(getTicker, { productId });
  return (
    <center>
      {productId}{' '}
      <NumberFlow
        value={ticker.price}
        format={{ style: 'currency', currency: 'USD' }}
      />
    </center>
  );
}
interface Props {
  productId: string;
}
render(<AssetPrice productId="BTC-USD" />);

🔴 Live Preview

Store▶

Behavior

Conditional Dependencies

Use null as the second argument to any Data Client hook means "do nothing."

// todo could be undefined if id is undefined
const todo = useLive(TodoResource.get, id ? { id } : null);

React Native

When using React Navigation, useLive() will trigger fetches on focus if the data is considered stale. useLive() will also sub/unsub with focus/unfocus respectively.

Types

Type

function useLive(
  endpoint: ReadEndpoint,
  ...args: Parameters<typeof endpoint> | [null]
): Denormalize<typeof endpoint.schema>;

With Generics

function useLive<
  E extends EndpointInterface<
    FetchFunction,
    Schema | undefined,
    undefined
  >,
  Args extends readonly [...Parameters<E>] | readonly [null],
>(
  endpoint: E,
  ...args: Args
): E['schema'] extends Exclude<Schema, null>
  ? Denormalize<E['schema']>
  : ReturnType<E>;

Examples

Bitcoin Price (polling)

When our component with useLive is rendered, getTicker will fetch at pollFrequency miliseconds.

More Demos