node.js - 穆特错误处理

Question

根据 Multer 的官方文档，这是在 Multer 中处理错误的正确方法。

var upload = multer().single('avatar')

app.post('/profile', function (req, res) {
  upload(req, res, function (err) {
    if (err) {
      // An error occurred when uploading
      return
    }

    // Everything went fine
  })
})

我的代码设置有点不同，我无法弄清楚如何更改下面的代码以这种方式处理错误。我最大的问题是我的 var 上传设置非常不同，以便与 Amazon S3 配合使用。我如何更改下面的代码以合并如上所示的错误处理？

var upload = multer({
    limits : { files: 3 },
    storage: multerS3({
        s3: s3,
        bucket: 'mybucket',
        key: function (req, file, cb) {
            var fileExtension = file.originalname.split(".")[1];
            var path = "uploads/" + req.user._id + Date.now() + "." + fileExtension;
            cb(null, path); 
        },
    destination: function(req, file, callback) {
    callback(null, './public/uploads');
  },
  filename: function(req, file, callback) {
    callback(null, Date.now() + file.originalname);
  }
    })

});

我的帖子路由是这样设置的...(仅显示部分代码)

router.post("/", upload.array('image', 3), function(req, res, next){


      var filepath = undefined;

      var filepath2 = undefined;

      var filepath3 = undefined;

    if(req.files[0]) {
        filepath = req.files[0].key;
    } 

      if(req.files[1]) {
        filepath2 = req.files[1].key;
    } 

     if(req.files[2]) {
        filepath3 = req.files[2].key;
    }

Answer 1

我不知道您是否仍然有疑问，但对于仍在关注它的任何人，您应该使用闭包的力量从内部调用您的函数。

所以你的代码将是这样的:

var upload = multer({
    limits : { files: 3 },
    storage: multerS3({
        s3: s3,
        bucket: 'mybucket',
        key: function (req, file, cb) {
            var fileExtension = file.originalname.split(".")[1];
            var path = "uploads/" + req.user._id + Date.now() + "." + fileExtension;
            cb(null, path); 
        },
    destination: function(req, file, callback) {
    callback(null, './public/uploads');
  },
  filename: function(req, file, callback) {
    callback(null, Date.now() + file.originalname);
  }
    })

}).array('image', 3);

router.post("/", function(req, res, next) {

 upload(req, res, function (err) {
 //deal with the error(s)   
if (err) {
      // An error occurred when uploading
      return
    }

    // Everything went fine
// put here whatever you want to do with your code
 var filepath = undefined;

      var filepath2 = undefined;

      var filepath3 = undefined;

    if(req.files[0]) {
        filepath = req.files[0].key;
    } 

      if(req.files[1]) {
        filepath2 = req.files[1].key;
    } 

     if(req.files[2]) {
        filepath3 = req.files[2].key;
    }

  });

});

这样你就可以自己处理错误，而不是使用express.js的默认处理程序。希望有帮助! :)