iOS-beacon-medium-article-componentWillMount.js

import Beacons        from 'react-native-beacons-manager';

class RNbeaconArticle extends Component {
  // ...
  componentWillMount(){
    //
    // ONLY non component state aware here in componentWillMount
    //
    // Request for authorization while the app is open
    Beacons.requestWhenInUseAuthorization();
    // Define a region which can be identifier + uuid,
    // identifier + uuid + major or identifier + uuid + major + minor
    // (minor and major properties are numbers)
    const region = {
      identifier: 'GemTot for iOS',
      uuid: '6665542b-41a1-5e00-931c-6a82db9b78c1' // => IMPORTANT: replace here with your beacon "uuid"
    };
    // Range for beacons inside the region
    Beacons.startRangingBeaconsInRegion(region);
  }
  // ...
}