Ajax 响应是文件下载

Ajax response is a file download

我正在使用 Polymer 的 iron-ajax 元素向服务器端点发送 XMLHTTPRequest:

 <iron-ajax
  id="ajax"
  method="POST"
  url="/export/"
  params=''
  handle-as="json"
  on-response="handleResponse"
</iron-ajax>

我的 Koa/Express-server 以这样的读取流响应:

router.post('/export' , function*(){

  var file = __dirname + '/test.zip';
  var filename = path.basename(file);
  var mimetype = mime.lookup(file);

  this.set('Content-disposition', 'attachment; filename=' + filename);
  this.set('Content-type', mimetype);
  this.body = fs.createReadStream(file);
})

如何在 handleResponse() 中启动下载? 理想情况下我根本不想处理响应并直接启动下载。

响应 headers 看起来(如预期的那样):

Content-disposition: attachment; filename=test.zip
Connection: keep-alive
Transfer-Encoding: chunked
Content-type: application/zip

如果您以八位字节流的形式返回文件数据,则可以像此处那样启动下载 -> Save file Javascript with file name

uriContent = "data:application/octet-stream," + encodeURIComponent(dataFromServer);

newWindow=window.open(uriContent, 'filename.txt');