index.js

"use strict";

import { DeviceEventEmitter, NativeModules } from 'react-native';
import promisify from 'es6-promisify';
import { EventEmitter } from 'events';

let isAppRegistered = false;
const {WeChat} = NativeModules;

// Event emitter to dispatch request and response from WeChat.
const emitter = new EventEmitter();

DeviceEventEmitter.addListener('WeChat_Resp', resp => {
  emitter.emit(resp.type, resp);
});

// Used only with promisify. Transform callback to promise result.
function translateError(err, result) {
  if (!err) {
    return this.resolve(result);
  }
  if (typeof err === 'string') {
    return this.reject(new Error(err));
  }
  this.reject(err);
}

function wrapRegisterApp(nativeFunc) {
  if (!nativeFunc) {
    return undefined;
  }
  const promisified = promisify(nativeFunc, translateError);
  return (...args) => {
    if (isAppRegistered) {
      return Promise.reject(new Error('App is already registered.'));
    }
    isAppRegistered = true;
    return promisified(...args);
  };
}

function wrapApi(nativeFunc) {
  if (!nativeFunc) {
    return undefined;
  }
  const promisified = promisify(nativeFunc, translateError);
  return (...args) => {
    if (!isAppRegistered) {
      return Promise.reject(new Error('registerApp required.'));
    }
    return promisified(...args);
  };
}

/**
 * `addListener` inherits from `events` module
 * @method addListener
 * @param {String} eventName - the event name
 * @param {Function} trigger - the function when event is fired
 */
export const addListener = emitter.addListener.bind(emitter);

/**
 * `once` inherits from `events` module
 * @method once
 * @param {String} eventName - the event name
 * @param {Function} trigger - the function when event is fired
 */
export const once = emitter.once.bind(emitter);

/**
 * `removeAllListeners` inherits from `events` module
 * @method removeAllListeners
 * @param {String} eventName - the event name
 */
export const removeAllListeners = emitter.removeAllListeners.bind(emitter);

/**
 * @method registerApp
 * @param {String} appid - the app id
 * @return {Promise}
 */
export const registerApp = wrapRegisterApp(WeChat.registerApp);

/**
 * @method registerAppWithDescription
 * @param {String} appid - the app id
 * @param {String} appdesc - the app description
 * @return {Promise}
 */
export const registerAppWithDescription = wrapRegisterApp(WeChat.registerAppWithDescription);

/**
 * Return if the wechat app is installed in the device.
 * @method isWXAppInstalled
 * @return {Promise}
 */
export const isWXAppInstalled = wrapApi(WeChat.isWXAppInstalled);

/**
 * Return if the wechat application supports the api
 * @method isWXAppSupportApi
 * @return {Promise}
 */
export const isWXAppSupportApi = wrapApi(WeChat.isWXAppSupportApi);

/**
 * Get the wechat app installed url
 * @method getWXAppInstallUrl
 * @return {String} the wechat app installed url
 */
export const getWXAppInstallUrl = wrapApi(WeChat.getWXAppInstallUrl);

/**
 * Get the wechat api version
 * @method getApiVersion
 * @return {String} the api version string
 */
export const getApiVersion = wrapApi(WeChat.getApiVersion);

/**
 * Open wechat app
 * @method openWXApp
 * @return {Promise}
 */
export const openWXApp = wrapApi(WeChat.openWXApp);

// wrap the APIs
const nativeShareToTimeline = wrapApi(WeChat.shareToTimeline);
const nativeShareToSession = wrapApi(WeChat.shareToSession);
const nativeSendAuthRequest = wrapApi(WeChat.sendAuthRequest);

/**
 * @method sendAuthRequest
 * @param {Array} scopes - the scopes for authentication.
 * @return {Promise}
 */
export function sendAuthRequest(scopes, state) {
  return new Promise((resolve, reject) => {
    WeChat.sendAuthRequest(scopes, state,() => {});
    // TODO(Yorkie): should we use once to instead?
    emitter.on('SendAuth.Resp', (resp) => {
      const result = resp.errCode;
      if (result === 0) {
        resolve(resp.code);
      } else {
        reject(result);
      }
    });
  });
}

/**
 * Share something to timeline/moments/朋友圈
 * @method shareToTimeline
 * @param {Object} data
 * @param {String} data.thumbImage - Thumb image of the message, which can be a uri or a resource id.
 * @param {String} data.type - Type of this message. Could be {news|text|imageUrl|imageFile|imageResource|video|audio|file}
 * @param {String} data.webpageUrl - Required if type equals news. The webpage link to share.
 * @param {String} data.imageUrl - Provide a remote image if type equals image.
 * @param {String} data.videoUrl - Provide a remote video if type equals video.
 * @param {String} data.musicUrl - Provide a remote music if type equals audio.
 * @param {String} data.filePath - Provide a local file if type equals file.
 * @param {String} data.fileExtension - Provide the file type if type equals file.
 */
export function shareToTimeline(data) {
  return nativeShareToTimeline(data);
}

/**
 * Share something to a friend or group
 * @method shareToSession
 * @param {Object} data
 * @param {String} data.thumbImage - Thumb image of the message, which can be a uri or a resource id.
 * @param {String} data.type - Type of this message. Could be {news|text|imageUrl|imageFile|imageResource|video|audio|file}
 * @param {String} data.webpageUrl - Required if type equals news. The webpage link to share.
 * @param {String} data.imageUrl - Provide a remote image if type equals image.
 * @param {String} data.videoUrl - Provide a remote video if type equals video.
 * @param {String} data.musicUrl - Provide a remote music if type equals audio.
 * @param {String} data.filePath - Provide a local file if type equals file.
 * @param {String} data.fileExtension - Provide the file type if type equals file.
 */
export function shareToSession(data) {
  return nativeShareToSession(data);
}