javascript - 在 promise 之外返回一个 promise 变量

Question

我需要从 promise 中获取变量的值，但我不能，因为它的范围。在我的例子中，我使用 Sequelize 将数据保存到 SQL 数据库，但我想处理类和 dataToReturn 我在第二次 save

后收到的 promise

.post('/', (req, res) =>  {
  const event = new Event(Events, Data, req.body)
  event.save()
  res.status(201).json("HERE I NEED THE 'dataToReturn' from the promise")
})

这是我的类事件

class Event {

    constructor(Events, Data, Event) {
        this._Data = Data,
        this._Events = Events
        this._Event = Event
    }

    save() {
        this._Data.build(this._Event.Data).save().then((res) =>
            this._Events.build({
                name: this._Event.name,
                date: this._Evento.fecha,
                photo1: this._Event.photo1,
                photo2: this._Event.photo2,
                idData: res.dataValues.id
            }).save().then((dataToReturn) => "???")) <-- dont know what to do here
        return dataToReturn    <-- I want to return that variable but I cant because scopes
    }

您有什么建议？我迷路了

Answer 1

   class Event {
        /**  
        * Same code
        */
    save() {            
        return this._Data.build(this._Event.Data).save().then((res) =>
                this._Events.build({
                    name: this._Event.name,
                    date: this._Evento.fecha,
                    photo1: this._Event.photo1,
                    photo2: this._Event.photo2,
                    idData: res.dataValues.id
                })).save();
    }

然后在你的 route 使用then:

.post('/', (req, res) =>  {
  const event = new Event(Events, Data, req.body)
  event.save().then((dataToReturn) => {
   res.status(201).json(dataToReturn);
  });
})