QHttpMultiPart not working

[daljit97]

I am trying to upload file (to Facebook) using QHttpMultiPart. Below is my code. This always gives me the following error.

"{"error":{"message":"(#324) Requires upload file","type":"OAuthException","code":324,"fbtrace_id":"Fsi2f\/H6ggp"}}"

However if I write the data manually without using QHttpMultiPart, the file is uploaded successfully (second snippet code)

QFile file(m_fileName);
QFileInfo fileInfo(m_fileName); // to get info on the file
bool open = file.open(QIODevice::ReadOnly);

if(open){
    // start the upload
    QHttpMultiPart *multiPart = new QHttpMultiPart(QHttpMultiPart::FormDataType);
    QHttpPart privacyPart;
    privacyPart.setHeader(QNetworkRequest::ContentTypeHeader, "text/plain; charset=UTF-8");
    privacyPart.setHeader(QNetworkRequest::ContentDispositionHeader, "form-data; name=\"privacy\"");
    privacyPart.setBody("{\"value\":\"FRIENDS_OF_FRIENDS\"}");

    QHttpPart filePart;
    filePart.setHeader(QNetworkRequest::ContentTypeHeader, "image/png");
    filePart.setHeader(QNetworkRequest::ContentDispositionHeader, "form-data; name=\"source\"; filename = \"" + fileInfo.fileName() + "\"");
    filePart.setRawHeader("Content-Transfer-Encoding", "binary");
    filePart.setBody(file.readAll());

    multiPart->append(privacyPart);
    multiPart->append(filePart);


    QNetworkRequest request(url);
    request.setRawHeader("Authorization", "OAuth " + accessToken.toUtf8());
    QNetworkReply* reply = m_networkAccessManager->post(request, multiPart);
    multiPart->setParent(reply); // delete multipart with reply

    // connect signals
    connect(reply, SIGNAL(uploadProgress(qint64,qint64)), this, SLOT(uploadProgress(qint64,qint64)));
    connect(reply, SIGNAL(finished()), this, SLOT(replyFinished()));
}
else{
    qDebug() << "Unable to open file" << fileName();
    qDebug() << file.errorString();
}

Second snippet (writing data manually)

// start the upload
QString boundary("----eidevelop1010101010");
QString contentType("multipart/form-data; boundary="+boundary);
QByteArray data;

data += QString("--"+boundary + "\r\n").toUtf8();
data += QString("Content-Disposition: form-data; name=\"source\";filename="+fileInfo.fileName()+"\r\n").toUtf8();
data += QString("Content-Type: image/jpeg\r\n\r\n").toUtf8();
data += file.readAll();
data += "\r\n";
data += QString("--" + boundary + "\r\n").toUtf8();
data += QString("--" + boundary + "\r\n").toUtf8();

QNetworkRequest request(url);
request.setHeader(QNetworkRequest::ContentTypeHeader, QVariant(contentType));
request.setHeader(QNetworkRequest::ContentLengthHeader, QVariant(QString::number(data.size())));
QNetworkReply* reply = m_networkAccessManager->post(request, data);
// connect signals
connect(reply, SIGNAL(uploadProgress(qint64,qint64)), this, SLOT(uploadProgress(qint64,qint64)));
connect(reply, SIGNAL(finished()), this, SLOT(replyFinished()));