node.js - 船长 : how to check if file was uploaded or not

Question

我正在使用 sails 0.10.5，它使用 skipper 进行文件上传。现在我有一个用户可以上传文件的表单。但是，文件上传不是强制性的。在后端，我需要检查文件是否已上传。

我的代码是这样的:

if(req.file('img')){
  req.file('img').upload({
    maxBytes: 10000000
  }, function (err, uploadedFiles){
    if(err){
      return res.json(500, err);
    }
    else if(uploadedFiles.length === 0){
      return res.json(500, {"error": "no file uploaded"});
    }
    else{
        // do something with image
    }
  });
}
else {
    // proceed without image
}

没有上传图片时出现以下错误:

Error: EMAXBUFFER: An Upstream (`NOOP_img`) timed out before it was plugged into a receiver. It was still unused after waiting 4500ms. You can configure this timeout by changing the `maxTimeToBuffer` option.
    at null.<anonymous> (/home/mandeep/projects/thirstt/node_modules/sails/node_modules/skipper/standalone/Upstream/Upstream.js:86:15)
    at Timer.listOnTimeout [as ontimeout] (timers.js:112:15)

第一个 if 条件总是被评估为真。如何检查用户是否没有上传任何文件？

Answer 1

将我的代码更改为

req.file('img').upload({
  maxBytes: 10000000
}, function (err, uploadedFiles){
  if(err){
    return res.json(500, err);
  }
  else if(uploadedFiles.length === 0){
    // proceed without files
  }
  else{
    //  handle uploaded file
  }
});

现在它工作正常