How to create HTTP request using form-data in QT

Question

I am trying to sent an HTTP request to server with key-value pair form-data in it. but I think I missing something while sending request that's why I didn't receive the correct response from server and I am not able to get whats missing in it.

I have an API which generates terrain data and create its file. Here is my curl request

 curl --location --request POST 'http://abc.xyz.com:123/generate' \
--header 'Content-Type;' \
--header 'Authorization: Bearer xxxxxxxx-xxxxxxx-xxxxxxx-xxx-xxx-xx-xxxxx' \
--form 'lat="19.3"' \
--form 'long="73.20"' \
--form 'radius="5"'

when I hit the request from postman it gives correct output but when I hit api from code it gives me "\n" as response.

Here is my code for same in QT

void RestApiHelper::generateTerrainData(float lat, float lon, qint32 radius)
{
    QUrl targateUrl = m_apiUrlHelper->getGenerateTerrainURL();
    qDebug() << targateUrl;
    QNetworkRequest request;
    request.setUrl(targateUrl);

    QString data = "xxxxx-xxxxxxx-xxxxxxxxx-xxxxxxxx";
    QString headerData = m_apiUrlHelper->getApiAuthorizationType() + data;
    request.setRawHeader( "Authorization", headerData.toLocal8Bit());
    qDebug() << "headerData :" << headerData.toLocal8Bit();

    QByteArray payload;
    payload.append("lat", lat);
    payload.append("long", lon);
    payload.append("radius", radius);

    QHttpMultiPart *multiPart = new QHttpMultiPart(QHttpMultiPart::FormDataType);
    QHttpPart textPart;
    //textPart.setHeader(QNetworkRequest::ContentTypeHeader, QVariant("form-data"));
    textPart.setHeader(QNetworkRequest::ContentDispositionHeader, QVariant("form-data; name=\"text\""));
    textPart.setBody(payload);
    multiPart->append(textPart);

    QNetworkAccessManager *restclient;
    restclient = new QNetworkAccessManager();
    //restclient->post(request,multiPart);
    QNetworkReply *reply = restclient->post(request, multiPart);
    multiPart->setParent(reply);

    disconnect(&m_generateTerrainProcessor, SIGNAL(dataReady(QString)), this, nullptr);
    connect(restclient, SIGNAL(finished(QNetworkReply*)), &m_generateTerrainProcessor, SLOT(handleAPIResponse(QNetworkReply*)));
    connect(&m_generateTerrainProcessor, SIGNAL(dataReady(QString)), this, SLOT(handleDataReady(QString)));
}

Here I sent data in kay/value pair to QByteArray and set this body to multiport. I tried with this way but didnt get expected result. The expected result is link of a generated file.

can anyone please tell me what I am doing wrong or is there any other method to assign kay-value pair form-data to the request in QT.

Answer 1

multipart/form-data is generally used for file uploads, for simple forms application/x-www-form-urlencoded is enough. Maybe api doesn't even support multipart.

QUrl targateUrl = m_apiUrlHelper->getGenerateTerrainURL();
qDebug() << targateUrl;
QNetworkRequest request;
request.setUrl(targateUrl);

QString data = "xxxxx-xxxxxxx-xxxxxxxxx-xxxxxxxx";
QString headerData = m_apiUrlHelper->getApiAuthorizationType() + data;
request.setRawHeader( "Authorization", headerData.toLocal8Bit());
request.setHeader(QNetworkRequest::ContentTypeHeader,
    "application/x-www-form-urlencoded");
qDebug() << "headerData :" << headerData.toLocal8Bit();

QUrlQuery postData;
postData.addQueryItem("lat", QString::number(lat));
postData.addQueryItem("long", QString::number(lon));
postData.addQueryItem("radius", QString::number(radius));

QNetworkAccessManager *restclient;
restclient = new QNetworkAccessManager();

QNetworkReply *reply = restclient->post(request, postData.toString(QUrl::FullyEncoded).toUtf8());
disconnect(&m_generateTerrainProcessor, SIGNAL(dataReady(QString)), this, nullptr);
connect(restclient, SIGNAL(finished(QNetworkReply*)), &m_generateTerrainProcessor, SLOT(handleAPIResponse(QNetworkReply*)));
connect(&m_generateTerrainProcessor, SIGNAL(dataReady(QString)), this, SLOT(handleDataReady(QString)));