React Native Detect Network Status

detectNetworkConfig.ts

// Example config from https://medium.com/@kulor/creating-an-offline-first-react-native-app-5534d7794969

import Config from 'modules/config';
import agent, { buildUrl } from 'modules/agent';

let online = true;
let timer = null as null | NodeJS.Timer;

const clearTimer = () => {
  if (timer) {
    clearInterval(timer);
    timer = null;
  }
};

const updateStatus = (isOnline: boolean, callback: any): void => {
  online = isOnline;

  callback({
    online,
  }); // Tell redux-offline that our status changed

  const interval = isOnline
    ? Config.API_PING_ONLINE_INTERVAL
    : Config.API_PING_OFFLINE_INTERVAL;

  clearTimer();
  timer = setInterval(
    () => checkNetworkStatus(callback),
    Number.parseInt(interval, 10),
  );
};

const checkNetworkStatus = async (callback: any) => {
  try {
    await agent.post('Register/ping');

    // Success, update our status
    if (!online) {
      console.devLog.info('detectNetwork change: Online');

      updateStatus(true, callback);
    }
  } catch (e) {
    // Something wrong, we are not offline
    if (online) {
      console.devLog.info('detectNetwork change: Offline');

      updateStatus(false, callback);
    }
  }
};

const detectNetwork = (callback: any): void => {
  updateStatus(true, callback);
};

export default detectNetwork;