react-native-firebase-for-netmera/dist/utils/events.js

.

import { NativeEventEmitter, NativeModules } from 'react-native';
import EventEmitter from 'react-native/Libraries/vendor/emitter/EventEmitter';
const NATIVE_EMITTERS = {};
const NATIVE_SUBSCRIPTIONS = {};
export const SharedEventEmitter = new EventEmitter();
export const getAppEventName = (module, eventName) => `${module.app.name}-${eventName}`;

const getNativeEmitter = (moduleName, module) => {
  const name = `${module.app.name}-${moduleName}`;
  const nativeModule = NativeModules[moduleName];

  if (!NATIVE_EMITTERS[name]) {
    NATIVE_EMITTERS[name] = new NativeEventEmitter(nativeModule);
  }

  return NATIVE_EMITTERS[name];
};
/**
 * Subscribe to a native event for js side distribution by appName
 *    React Native events are hard set at compile - cant do dynamic event names
 *    so we use a single event send it to js and js then internally can prefix it
 *    and distribute dynamically.
 *
 * @param moduleName
 * @param module
 * @param eventName
 * @private
 */


const subscribeToNativeModuleEvents = (moduleName, module, eventName) => {
  if (!NATIVE_SUBSCRIPTIONS[eventName]) {
    const nativeEmitter = getNativeEmitter(moduleName, module);
    nativeEmitter.addListener(eventName, event => {
      if (event.appName) {
        // native event has an appName property - auto prefix and internally emit
        SharedEventEmitter.emit(`${event.appName}-${eventName}`, event);
      } else {
        // standard event - no need to prefix
        SharedEventEmitter.emit(eventName, event);
      }
    });
    NATIVE_SUBSCRIPTIONS[eventName] = true;
  }
};

export const initialiseNativeModuleEventEmitter = (module, config) => {
  const {
    events,
    moduleName
  } = config;

  if (events && events.length) {
    for (let i = 0, len = events.length; i < len; i++) {
      subscribeToNativeModuleEvents(moduleName, module, events[i]);
    }
  }
};