DISCLAIMER:

This library is meant to be used with the unleash-proxy. The proxy application layer will sit between your unleash instance and your client applications, and provides performance and security benefits. DO NOT TRY to connect this library directly to the unleash instance, as the datasets follow different formats because the proxy only returns evaluated toggle information.

Installation

npm install @unleash/proxy-client-react
// or
yarn add @unleash/proxy-client-react

Import the provider like this in your entrypoint file (typically index.js/ts):

import FlagProvider from '@unleash/proxy-client-react';

const config = {
  url: 'https://HOSTNAME/proxy',
  clientKey: 'PROXYKEY',
  refreshInterval: 15,
  appName: 'your-app-name',
  environment: 'dev',
};

ReactDOM.render(
  <React.StrictMode>
    <FlagProvider config={config}>
      <App />
    </FlagProvider>
  </React.StrictMode>,
  document.getElementById('root')
);

To check if a feature is enabled:

import { useFlag } from '@unleash/proxy-client-react';

const TestComponent = () => {
  const enabled = useFlag('travel.landing');

  if (enabled) {
    return <SomeComponent />
  }
  return <AnotherComponent />
};

export default TestComponent;

To check variants:

import { useVariant } from '@unleash/proxy-client-react';

const TestComponent = () => {
  const variant = useVariant('travel.landing');

  if (variant.enabled && variant.name === "SomeComponent") {
    return <SomeComponent />
  } else if (variant.enabled && variant.name === "AnotherComponent") {
    return <AnotherComponent />
  }
  return <DefaultComponent />
};

export default TestComponent;

Defer rendering until flags fetched

useFlagsStatus retrieves the ready state and error events. Follow the following steps in order to delay rendering until the flags have been fetched.

import { useFlagsStatus } from '@unleash/proxy-client-react'

const MyApp = () => {
  const { flagsReady, flagsError } = useFlagsStatus();

  if (!flagsReady) {
    return <Loading />
  }
  return <MyComponent error={flagsError}/>
}

Updating context

Follow the following steps in order to update the unleash context:

import { useUnleashContext, useFlag } from '@unleash/proxy-client-react'

const MyComponent = ({ userId }) => {
  const variant = useFlag("my-toggle");
  const updateContext = useUnleashContext();

  useEffect(() => {
    // context is updated with userId
    updateContext({ userId })
  }, [])

  useEffect(async () => {
    // Can wait for the new flags to pull in from the different context
    await updateContext({ userId });

    console.log('new flags loaded for', userId);
  }, []);
}