App.js

/**
 * Sample React Native App
 * https://github.com/facebook/react-native
 *
 * @format
 * @flow
 * @lint-ignore-every XPLATJSCOPYRIGHT1
 */

import React, { Component } from 'react';
import {
  Platform,
  StyleSheet,
  Text,
  View,
  NativeAppEventEmitter,
  AsyncStorage,
} from 'react-native';
import AppleHealthKit from 'rn-apple-healthkit';
import LocalNotifications from 'react-native-local-notifications';
import moment from 'moment';

const instructions = Platform.select({
  ios: 'Press Cmd+R to reload,\n' + 'Cmd+D or shake for dev menu',
  android:
    'Double tap R on your keyboard to reload,\n' +
    'Shake or press menu button for dev menu',
});

type Props = {};
export default class App extends Component<Props> {
  constructor() {
    super();

    this.state = {
      HKData: '...',
    };
  }

  componentDidMount() {
    AppleHealthKit.initHealthKit(
      {
        permissions: {
          read: ['HeartRate'],
        },
      },
      (e, r) => {
        console.log(`HK Initiated e:${e} r: ${r}`);
        AppleHealthKit.setObserver({ type: 'HeartRate' });
        NativeAppEventEmitter.addListener('observer', result => {
          AsyncStorage.setItem('RNHK', JSON.stringify(result) || 'No Data');
          LocalNotifications.createNotification(
            1,
            JSON.stringify(result) || 'No Data',
            moment()
              .add(1000 * 5)
              .format('yyyy-mm-dd hh:mm'),
            'default'
          );
        });
      }
    );
    AsyncStorage.getItem('RNHK').then(HKData => {
      this.setState({ HKData });
    });
  }

  render() {
    return (
      <View style={styles.container}>
        <Text style={styles.welcome}>{`${this.state.HKData}`}</Text>
      </View>
    );
  }
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    backgroundColor: '#F5FCFF',
  },
  welcome: {
    fontSize: 20,
    textAlign: 'center',
    margin: 10,
  },
  instructions: {
    textAlign: 'center',
    color: '#333333',
    marginBottom: 5,
  },
});