NodeJS:承诺中的回调

Question

我正在登录两个不同的服务，我需要将两个响应推送到一个数组。为此，我正在创建一个 promiseResult ，在其中，还有另外两个登录承诺：

var promiseResult = new Promise(function(resolveResult, rejectResult) {
  var dataAvailable = []
  // first promise for the first login
  var promiseFirstLogin = new Promise(function(resolve, reject) {
    login.returnData(email, password, (dataFirstLogin) => {
      resolve(dataFirstLogin)
    })
  })
  promiseFirstLogin.then(function(dataFirstLogin) {
    return dataFirstLogin
  })
  .then(function(dataFirstLogin) {
    // pushing the data of the first login
    dataAvailable.push({dataFirstLogin: dataFirstLogin})
    return dataAvailable
  })
  // if the user puts the login for the second service
  if (second_login_username) {
    // second promise of the second login
    var promiseSecondLogin = new Promise(function(resolve, reject) {
      login.returnSecondData(secondUsername, secondPassword, (secondData) => {
        resolve(secondData)
      })
    })
    promiseSecondLogin.then(function(secondData) {
      return secondData
    })
    .then(function(secondData) {
      // pushing second data to the same array
      dataAvailable.push({secondData: secondData})
      return dataAvailable
    })
  }
  // logs undefined (?)
  console.log('->', dataAvailable);
  /* 
  I try to resolve the array with my data, but it needs to be inside the promises. 
  However, as I have multiple data sources, I cannot simply put the resolve function 
  inside each promise. How to proceed with this? 
  */
  resolveResult(dataAvailable)
})
promiseResult.then(function (dataAvailable) {
  // I try to get the array with my data... but unsuccessfully 
  return dataAvailable
})
.then(function (dataAvailable) {
  dataAvailable.reduce(function(result, item) {
    var key = Object.keys(item)[0]
    result[key] = item[key];
    res.send(JSON.stringify(result, null, 3));
  }, {})
})

正如我在评论中所写，我尝试使用来自两次登录的数据resolve()数组，但它需要在承诺内。但是，我有多个数据源，我不能简单地将resolve()放在每个承诺中。如何放置一个包含我的两个服务数据的单个resolve()？

任何帮助将不胜感激。

Answer 1

你可以有一系列的承诺。如果用户为第二个服务添加登录信息，请将该承诺添加到阵列中。

然后，使用 Promise.all(yourPromiseArray).then((values)=>{ //All promises are resolved. Do something with the values array })