Use React's Context API in React Native (0.59.0) to have network connectivity status globally available. Gist for Medium article: https://medium.com/@jvandenaardweg/easily-manage-connection-status-updates-in-react-native-28c9b4b0647f

App.jsx

import React from 'react';

import { NetworkProvider } from './NetworkProvider';
import { ExampleComponent } from './ExampleComponent';

export default class App extends React.PureComponent {
  render() {
    return (
      <NetworkProvider>
        <ExampleComponent />
      </NetworkProvider>
    );
  }
}

ExampleComponent.jsx

import React from 'react';
import { View, Text } from 'react-native';

import { NetworkContext } from './NetworkProvider';

export class ExampleComponent extends React.PureComponent {
  static contextType = NetworkContext;

  render() {
    return (
      <View>
        <Text>You are now {this.context.isConnected ? 'online' : 'offline'}</Text>
      </View>
    );
  }
}

index.js

import { AppRegistry } from 'react-native';
import App from './App'
import { name as appName } from './app.json';

AppRegistry.registerComponent(appName, () => App);

NetworkProvider.jsx

import React from 'react';
import NetInfo from '@react-native-community/netinfo';

export const NetworkContext = React.createContext({ isConnected: true });

export class NetworkProvider extends React.PureComponent {
  state = {
    isConnected: true
  };

  componentDidMount() {
    NetInfo.isConnected.addEventListener('connectionChange', this.handleConnectivityChange);
  }

  componentWillUnmount() {
    NetInfo.isConnected.removeEventListener('connectionChange', this.handleConnectivityChange);
  }

  handleConnectivityChange = isConnected => this.setState({ isConnected });

  render() {
    return (
      <NetworkContext.Provider value={this.state}>
        {this.props.children}
      </NetworkContext.Provider>
    );
  }
}