How to send data along with file in http POST (angularjs + expressjs)?

问题

Situation

I implemented file uploading. Front-end code is taken from popular tutorial. I send POST in service:

myApp.service('fileUpload', ['$http', function ($http) {
    this.uploadFileToUrl = function(file, uploadUrl){
        var fd = new FormData();
        fd.append('file', file);

        $http.post(uploadUrl, fd, {
             transformRequest: angular.identity,
             headers: {'Content-Type': undefined}
        })

        .success(function(){
        })

        .error(function(){
         });
        }
    }]);

Typical multer usage in back-end:

exports.postFile = function (req, res) {

    var storage = multer.diskStorage({ //multers disk storage settings
        destination: function (req, file, cb) {
            cb(null, '../documents/')
        },
        filename: function (req, file, cb) {
            cb(null, file.originalname)
        }
    });

    var upload = multer({ //multer settings
        storage: storage
    }).single('file');

    upload(req, res, function (err) {
        if (err) {
            res.json({error_code: 1, err_desc: err});
            return;
        }
        res.json({error_code: 0, err_desc: null});
    })

};

That works.

Question

How to send some data in the same POST, let say string "additional info"?

What I tried

I tried to add data in service, i.e.:

...
var fd = new FormData();
fd.append('file', file);
fd.append('model', 'additional info');

$http.post(uploadUrl, fd, {...})

It seems to be sent, but I don't know how to receive it in back-end. Tried to find it in req (without success).

回答1:

To send data (i.e. json) and file in one POST request add both to form data:

myApp.service('fileUpload', ['$http', function ($http) {
    this.uploadFileToUrl = function(file, uploadUrl){
        var fd = new FormData();
        fd.append('file', file);

        var info = {
            "text":"additional info"
        };
        fd.append('data', angular.toJson(info));

        $http.post(uploadUrl, fd, {
             transformRequest: angular.identity,
             headers: {'Content-Type': undefined}
        })

        .success(function(){
        })

        .error(function(){
        });
    }
}]);

On server side it's in req.body.data, so it can be received i.e. like this:

upload(req, res, function (err) {
    if (err) {
        res.json({error_code: 1, err_desc: err});
        return;
    }

    console.log(req.body.data);

    res.json({error_code: 0, err_desc: null});
})

回答2:

You can get the file from req.files and save it with fs.writeFile.

fs.readFile(req.files.formInput.path, function (err, data) {
  fs.writeFile(newPath, data, function (err) {
    if (err) {
    throw err;
    }
    console.log("File Uploaded");
  });
});

回答3:

You can do something like this:

          $http({
                url: url, 
                method: 'POST',
                data: json_data,
                headers: {'Content-Type': 'application/json'}
          }).then(function(response) {
                var res = response.data;
                console.log(res);
          }, function errorCallback(response) {
              // called asynchronously if an error occurs
             // or server returns response with an error status.
          });

Or just add the data property to your function.

    var userObject = {
    email: $scope.user.email,
    password: $scope.user.password,
    fullName: $scope.user.fullName
    };

    $http.post(uploadUrl, fd, {
         transformRequest: angular.identity,
         data: userObject,
         headers: {'Content-Type': 'application/json'}
    })

You can try something like this on the backend.

req.on('data', function (chunk) {
    console.log(chunk);
});

来源：https://stackoverflow.com/questions/40773641/how-to-send-data-along-with-file-in-http-post-angularjs-expressjs

标签

angularjs

express

multer