Qt: Post data to server - c++

Question

I try to implement a REST client in order to get a Service Ticket from my server. For those of you who don't know CAS: A Service Ticket can be requested by showing a TGT. The TGT can be requested by a successful login basically. Maybe that is not even relevant.
I quess I have a error in my connect. My server is not even reacting to that connection and the reply is emptry. However for some reason reply->error() == QNetworkReply::NoErroris true.
What am I doing wrong?
bool Client::validateTGT(QString const & tgt) const
{
bool isValid = false;
QUrl url = QUrl("https://localhost:8943/cas/v1/tickets/" + tgt);
QUrl postData;
postData.addQueryItem("service", "https://test.de");
QNetworkRequest request(url);
request.setHeader(QNetworkRequest::ContentTypeHeader,
"application/x-www-form-urlencoded");
//QNetworkAccessManager *networkManager = new QNetworkAccessManager();
QObject::connect(manager, SIGNAL(finished(QNetworkReply*)),
this, SLOT(replyFinished(QNetworkReply*)), Qt::AutoConnection);
QNetworkReply *reply = manager->post(request, postData.encodedQuery());
QByteArray replyData = reply->readAll();
QString s_data = QString::fromAscii(replyData.data());
if (reply->error() == QNetworkReply::NoError)
{
isValid = true;
}
return isValid;
}
EDIT: replyFinished as requested
.h:
public slots:
void replyFinished(QNetworkReply *);
.cpp:
void CCASRESTClient::replyFinished(QNetworkReply *reply)
{
QByteArray replyData = reply->readAll();
serviceTicket = QString::fromAscii(replyData.data());
}

Answer 1

The slot replyFinished is called by the event loop when the reply has arrived from the server, this happens far after your function validateTGT has returned.
The manager object receives the reply and then emits the finished signal, this is when the slot replyFinished is called. It doesn't make sense to return a value from there. Just ask yourself, who is the caller function that will get this return value? validateTGT has already returned, thus it is not getting anything.
Your slot needs to be declared to return void, and you should do whatever you want to do with the reply in your replyFinished slot.
In general, if you have any slot that returns a value, the return value cannot be retrieved unless this slot was called as a normal function (Obviously this is not the case here).