Javascript 如何在我的案例中使用promise for loop

我没有在for循环中使用承诺。我需要用承诺的方法成功完成需求

getUserInfoById: () ->
  ids = [196658162, 244668541, 84634196, 1234567, 45367181]
  last = Promise.resolve()
  for id of ids
    id = ids[id]
    url = "https://api.vk.com/method/users.get?fields=photo,status&user_ids=#{id}&access_token=#{atom.config.get('vk-messenger.apiToken')}&v=5.60"
    last = last.then(() -> reqWithPromise(url));

reqWithPromise = (url) ->
  https.get url, (@response) ->
    @response.on 'data', (chunk) ->
      @userModel = JSON.parse(chunk)['response'][0]
      console.log @userModel.id + ' ' + @userModel.first_name

我得到

 5 times: 45367181 Daniil

---

您可以使用

reduce

并承诺按顺序处理您的通话：

getUserInfoById: () ->
  ids = [196658162, 244668541, 84634196, 1234567, 45367181]
  ids.reduce((memo, id)->
    # Check that the previous promise is resolved
    memo.then ->
      url = "https://api.vk.com/method/users.get?fields=photo,status&user_ids=#{id}&access_token=#{atom.config.get('vk-messenger.apiToken')}&v=5.60"
      # Call next promise func.
      reqWithPromise(url)
  , Q()) #First memo value is a promise

reqWithPromise = (url) ->
  # should return a promise
  deferred = Q.defer()
  https.get url, (@response) ->
    @response.on 'data', (chunk) ->
      @userModel = JSON.parse(chunk)['response'][0]
      console.log @userModel.id + ' ' + @userModel.first_name
      deferred.resolve(@userModel)
  deferred.promise

可能重复的