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node.jsfile-uploadasyncfileuploadmulter

multer nodejs modules onFileUploadStart file.size returns 0

I am creating an app that receives file from several clients in node.js. For that i use express multer node modules.

In the following code I deal with the file upload:

app.use(multer({ dest: './uploads/',
    rename: function (fieldname, filename){
        return filename;
    },
    onFileUploadStart: function(file){
        console.log("file size: " + file.size);
        console.log(file.originalname + ' is starting...');
    },
    onFileUploadComplete: function(file){
        console.log(file.fieldname + ' uploaded to ' + file.path);
        done = true;
    },
    onFileUploadData: function(file, data){
        //console.log("data being received " + data);
    }
}));

But when I enter inside the onFileUploadStart the file.size is 0.

A multer file object is a JSON object with the following properties so I know that the size property exists.

fieldname - Field name specified in the form
originalname - Name of the file on the user's computer
name - Renamed file name
encoding - Encoding type of the file
mimetype - Mime type of the file
path - Location of the uploaded file
extension - Extension of the file
size - Size of the file in bytes
truncated - If the file was truncated due to size limitation
buffer - Raw data (is null unless the inMemory option is true)

Why is the size being returned as 0?

EDIT: although the file size returns 0 other properties of the file like file.originalname are working and returning the proper names.

EDIT2: when i print the file inside the onFileUploadStart function i get the following properties and associated values:

{
    filename: 'userFile',
    originalname: 'name.png',
    name: 'name.png',
    encoding: '7bit',
    mimetype: 'image/png',
    path: 'uploads\\name.png',
    extension: 'png',
    size: 0,
    truncated: null,
    buffer: null
}

Why is the multer node module sending everything correctly but the file size?

EDIT3:

request.body prints the following:

{ submit: 'upload file' }

which is weird. i am printing the request body inside the following code:

app.post('/upload/', function(request, response){
    console.log(request.body);
    if (done == true){
        response.end('file uploaded');
    }
});

index.html file where the client can upload a file:

<html>
    <head>

    </head>
    <body>
        <form id= "upload" enctype= "multipart/form-data" action="/upload/" method="post">
            <input type="file" name="userFile" />
            <input type="submit" name="submit" value="upload file" />
        </form>
    </body>
</html>
Solution

  • You can only get total the file size after the upload has completed, since the file is streamed.

    If you look at the source you can see the initial size is set to 0, then is increased along with the data event.