你要等到所有的promise都完成了吗？

Question

我正在做一个forEach循环，它对Cloudinary进行API调用，我正在用响应数据构建一个数组。

一旦收集到数据，我需要将其发送到其他API。

在发送数据之前，我如何等待promise得到解决并收集数据？

这是我的代码：

app.controller 'ProductImageUploaderController', ($upload, $routeParams, Product) ->

  $routeParams.photos = []

  @startUpload = ->
    @files.forEach (file) ->
      upload = $upload.upload(
        url: 'https://api.cloudinary.com/v1_1/' + $.cloudinary.config().cloud_name + '/upload'
        fields:
          upload_preset: $.cloudinary.config().upload_preset
          tags: 'dev'
          folder: 'dev'
        file: file
      )
      upload.success (data) ->
        $routeParams.photos.push(file)

    # Once the $routeParams.photos array is built, this is when I'd like to pass the data on.

  return

Answer 1

这里需要的是$q.all：

app.controller 'ProductImageUploaderController', ($upload, $routeParams, Product, $q) ->

    $routeParams.photos = []

    @startUpload = ->
        pFiles = @files.map (file) ->
            $upload.upload(
                url: 'https://api.cloudinary.com/v1_1/' + $.cloudinary.config().cloud_name + '/upload'
                fields:
                    upload_preset: $.cloudinary.config().upload_preset
                    tags: 'dev'
                    folder: 'dev'
                file: file
            ).then (response) -> file

        $q.all(pFiles).then (uploadedFiles) ->
            $routeParams.photos = uploadedFiles
            #all files have been uploaded. use tham as you wish

    return