qnetworkreply no statuscode or error but failing - c++

Question

Im trying to find out what goes wrong when doing a get request in qt.
I have the following slots attached to my networkmanager:
connect(mgr,SIGNAL(finished(QNetworkReply*)),this,SLOT(requestFinished(QNetworkReply*)));
connect(mgr, SIGNAL(error(QNetworkReply::NetworkError)),
this, SLOT(slotError(QNetworkReply::NetworkError)));
The request finished is like:
void FirebaseInteractor::requestFinished(QNetworkReply *rep)
{
QVariant statusCode = rep->attribute( QNetworkRequest::HttpStatusCodeAttribute );
int status = statusCode.toInt();
if ( status != 200 )
{
QString reason = rep->attribute( QNetworkRequest::HttpReasonPhraseAttribute ).toString();
qDebug() << "Pushnotification Request failed : " <<reason;
}
else{
qDebug() << "Pushnotification has been send: ";
}
if ( !statusCode.isValid() )
{
QString status = statusCode.toString(); // or status_code.toInt();
qDebug() << "Failing " << status;
int code = statusCode.toInt();
qDebug() << "Pushnotification Request failed invalid status code." << QString::number(code);
QString reason = rep->attribute( QNetworkRequest::HttpReasonPhraseAttribute ).toString();
qDebug() << "reason " << reason;
return;
}
}
However Status is always empty Failing and reason is printed but there is no value after it (i was expecting a reason e.g. timeout, 401 etc).
I also tried:
int status = statusCode.toInt();
if ( status != 200 )
{
QString reason = rep->attribute( QNetworkRequest::HttpReasonPhraseAttribute ).toString();
qDebug() << "Pushnotification Request failed : " <<reason;
}
else{
qDebug() << "Pushnotification has been send: ";
}
But all reasons/codes are empty.
I also added:
void FirebaseInteractor::slotError(QNetworkReply::NetworkError error)
{
qDebug() << "slotError" << error;
}
but this is not called.
How can I find out whats going wrong?

Answer 1

You can get the error directly using:
qDebug() << reply->error();
This won't work if the network request never happened:
if ( !statusCode.isValid() )
Because this means that the QVariant itself is invalid and has type QMetaType::UnknownType Documentation. Hence it will not give any information about what went wrong in the http request. To fix this, here's a simple example:
if (statusCode.isValid()) { // it needs to be valid
qDebug() << "Status Code: " << statusCode.toString();
}
Alternatively, you can switch on QNetworkReply::Error()
void FirebaseInteractor::requestFinished(QNetworkReply *rep)
{
switch (rep->error())
{
case QNetworkReply::NoError:
// No error
return;
case QNetworkReply::TimeoutError:
{
auto httpStatus =
reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();
auto httpStatusMessage = reply->attribute(
QNetworkRequest::HttpReasonPhraseAttribute).toByteArray();
//...
break;
}
}
}