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问题:

I'm trying to upload a file using formidable, following the tutorial in the Node Beginner Book. Following this code, I have a server modules that passes the request object to a requestHandler module. The main page loads a form with the following handler:

function start(response) {
    console.log("Request handler 'start' was called.");

    var body = '<html>'+
        '<head>'+
        '<meta http-equiv="Content-Type" content="text/html"; '+
        'charset=UTF-8" />'+
        '</head>'+
        '<body>'+
        '<form action="/upload" enctype="multipart/form-data method="post">'+
        '<input type="file" name="upload" multiple="multiple"'+
        '<input type="submit" value="Upload file" />'+
        '</form>'+
        '</body>'+
        '</html>';

    response.writeHead(200, {"Content-Type": "text/html"});
    response.write(body);
    response.end();

}

When the form is submitted, the /upload path triggers the following upload handler function:

function upload(response,request) {
    console.log("Request handler 'upload' was called.");

    var form = new formidable.IncomingForm();
    console.log("about to parse");
    form.parse(request, function(error, fields, files) {
        console.log("parsing done");

        console.log(util.inspect({error: error, fields: fields, files: files}));

        fs.rename(files.upload.path, "/tmp/test.png", function(error) {
            if (error) {
                console.log(error);
                fs.unlink("/tmp/test.png");
                fs.rename(files.upload.path, "/tmp/test.png");
            }
        });
        response.writeHead(200, {"Content-Type": "text/html"});
        response.write("received image:<br/>");
        response.write("<img src='/show' />");
        reponse.end();
    });

}

When the upload button is clicked, however, the server crashes with the following error:

/home/****/Coding/nodebeginner/requestHandlers.js:38
        fs.rename(files.upload.path, "/tmp/test.png", function(erro
                              ^
TypeError: Cannot read property 'path' of undefined
    at /home/****/Coding/nodebeginner/requestHandlers.js:38:25
    at IncomingForm.<anonymous> (/home/****/Coding/nodebeginner/node_modules/formidable/lib/incoming_form.js:104:9)
    at IncomingForm.EventEmitter.emit (events.js:92:17)
    at IncomingForm._maybeEnd (/home/****/Coding/nodebeginner/node_modules/formidable/lib/incoming_form.js:551:8)
    at Object.end (/home/****/Coding/nodebeginner/node_modules/formidable/lib/incoming_form.js:238:12)
    at IncomingMessage.<anonymous> (/home/****/Coding/nodebeginner/node_modules/formidable/lib/incoming_form.js:129:30)
    at IncomingMessage.EventEmitter.emit (events.js:92:17)
    at _stream_readable.js:920:16
    at process._tickCallback (node.js:415:13)

So evidently the files variable is undefined. I thought there might be an error, but no the error variable is set to null. So I'm a bit stumped here. Ideas?

回答1:

I had same problem. I think you see those line code on Node Beginner Book, at the end of the book. I fixed it by removed follow code on server.js file:

//      req.setEncoding("utf8");
//        req.addListener("data", function(postDataChunk) {
//            postData += postDataChunk;
//        });
//        req.addListener("end", function() {
//            route(handle, pathname, res, req);
//        });

Just do:

route(handle, pathname, res, req);

And last, you must be careful at html form tags.

Sorry for my English and best wishes!

***VinRover Nguyen***

回答2:

I'm also having the same issue. Your form tag is missing a closing double quote(") on the enctype attribute.

回答3:

I've got stuck at the same issue. Sounds like upload class have been replaced or misspelled. Try to change the reference from files.upload.path to files.Upload.path . It works here. Check out the master branch for further information : Git

回答4:

Looks like you have some errors in your "var body". Try :

var body = '<html>' +
  '<head>' +
  '<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />' +
  '</head>' +
  '<body>' +
  '<form action="/upload" enctype="multipart/form-data" method="post">' +
  '<input type="file" name="upload" multiple="multiple">' +
  '<input type="submit" value="Upload File">' +
  '</form>' +
  '</bidy>' +
  '</html>';

回答5:

There is an error in the names of the parameters for the callback in form.parse.

The Node Beginner Book shows the code as:

form.parse(request, function(error, fields, files) {
    //code
}

The parameters should not be plural in the callback function:

form.parse(request, function(error, field, file) {
    //code
}

Take a look at IncomingForm.prototype.parse in /node_modlues/formidable/lib/incoming_form.js. The callback is listening for singular "field" and "file" .