Question

嗨，编码员我对此代码有疑问：

const ForVideo = async data =>
  data.map(story => {
    return {
       videoUrl: story.video.versions[0].url,
       instagramId: story.pk,
       videoFilename: MediaDownloader({
       url: story.video.versions[0].url,
       dest: "/Users/Hernan/Haip/media/" + story.account.pk + "/story/"
       }),
       expiresAt: story.expiringAt,
       tappableObjects: HashMention(story),
       influencerId: story.account.pk,
       takenAt: story.takenAt,
       isVideo: true,
       videoDuration: story.video.duration,
       displayUrl: story.imageVersions2.candidates[0].url,
       imageFilename: MediaDownloader({
         url: story.imageVersions2.candidates[0].url,
         dest: "/Users/Hernan/Haip/media/" + story.account.pk + "/story/"
       }),
       callToAction: null
     };
  });

我调用ForVideo (data)函数返回一个新的JSON，但问题是这不会返回项目videoFilename和imageFilename（来自MediaDownloader()函数的URL）

我如何应用异步/等待或答应获取完整的JSON并等待MediaDownloader()函数完成？

MediaDownloader()：

MediaDownloader: async options => {
let dir = options.dest;

 try {
  fs.ensureDirSync(dir);
  const { filename, image } = await download.image(options);
  return filename;
 } catch (e) {
   console.error(e);
   }
}

Answer 1

尝试一下。

 const ForVideo = data =>
  data.map(async story => {
    return {
      videoFilename: await MediaDownloader({
        url: story.video.versions[0].url,
        dest: "/Users/Hernan/Haip/media/" + story.account.pk + "/story/"
      })
    };
 });

MediaDownloader: options => {
  return new Promise((resolve, reject) => {
    let dir = options.dest;
    try {
      fs.ensureDirSync(dir);
      const { filename, image } = download.image(options);
      resolve(filename);
    } catch (e) {
      reject(e);
    }
  });
}

如何在.map中使用异步

1 个答案: