XMPP CSI on React Native https://xmpp.org/extensions/xep-0352.html

csi.js

import {AppState} from 'react-native';
import xml from './xmpp/packages/xml';

// https://xmpp.org/extensions/xep-0352.html
// https://facebook.github.io/react-native/docs/appstate

module.exports = function csi({entity}) {
  let supported = false;
  let inactive = false;

  function processAppState(state) {
    if (!supported) return;
    if (state === 'background') {
      if (inactive === true) return;
      entity.send(xml('inactive', {xmlns: 'urn:xmpp:csi:0'}));
      inactive = true;
    } else {
      if (inactive === false) return;
      entity.send(xml('active', {xmlns: 'urn:xmpp:csi:0'}));
      inactive = false;
    }
  }

  AppState.addEventListener('change', processAppState);

  entity.on('nonza', nonza => {
    if (!nonza.is('features', 'http://etherx.jabber.org/streams')) return;
    supported = !!nonza.getChild('csi', 'urn:xmpp:csi:0');
  });

  entity.on('online', () => {
    processAppState(AppState.currentState);
  });
};