QNetworkAccessManager signals not working

Defohin

I don't know why but it doesn't work at all, not the finished, error, or sslErrors, none of them:

auto manager = new QNetworkAccessManager;

QNetworkRequest request;
request.setUrl(QUrl("http://qt-project.org"));
request.setRawHeader("User-Agent", "MyOwnBrowser 1.0");

QNetworkReply *reply = manager->get(request);
connect(reply, SIGNAL(readyRead()), this, SLOT(replyReadyRead()));
connect(reply, SIGNAL(error(QNetworkReply::NetworkError)),
                this, SLOT(replyError(QNetworkReply::NetworkError)));
connect(reply, SIGNAL(sslErrors(QList<QSslError>)),
                this, SLOT(replySslErrors(QList<QSslError>)));

I even tried to use the new syntax like connect(networkReply, static_cast<void(QNetworkReply::*)(QNetworkReply::NetworkError)>(&QNetworkReply::error), [=](QNetworkReply::NetworkError code){ /* ... */ }); but doesn't work either...
What is happening?

raven-worx

@Defohin

check the return value of connect()
check the console for warnings regarding the connect() statements
show some more code, what happen with the reply/QNetworkAccessManager?

Defohin

@raven-worx

1 - All of them is returning true
2 - There's nothing on the console
3 - I just realized that I forgot to connect finished ...

auto manager = new QNetworkAccessManager;

QNetworkRequest request;
request.setUrl(QUrl("http://qt-project.org"));
request.setRawHeader("User-Agent", "MyOwnBrowser 1.0");

QNetworkReply *reply = manager->get(request);
auto r1 = connect(reply, SIGNAL(finished()), this, SLOT(replyFinished()));
auto r2 = connect(reply, SIGNAL(readyRead()), this, SLOT(replyReadyRead()));
auto r3 = connect(reply, SIGNAL(error(QNetworkReply::NetworkError)),
        this, SLOT(replyError(QNetworkReply::NetworkError)));
auto r4 = connect(reply, SIGNAL(sslErrors(QList<QSslError>)),
        this, SLOT(replySslErrors(QList<QSslError>)));

qDebug() << r1 << r2 << r3 << r4;

The rest of the code is the slots, but it has nothing special:

void NYTimes::replyFinished()
{
    qDebug() << "it is working";
}

void NYTimes::replyReadyRead()
{
    qDebug() << "ready to read";
}

void NYTimes::replyError(QNetworkReply::NetworkError error)
{
    qDebug() << error;
}

void NYTimes::replySslErrors(QList<QSslError> errors)
{
    qDebug() << errors;
}

And yes, it's not working either.

raven-worx

@Defohin
if all connects are successfull (by returning true), the only thing i can think of is that the reply (or QNAM) or the object holding the slots are deleted?

Defohin

It's not being deleted, I'm using pointers to test if it has something to do with that, but it doesn't work either.

m.sue

Hi,
can you try with a site that does not redirect to https e.g. http://en.cppreference.com/w/. Maybe that's a problem.
-Michael.

Defohin

It doesn't work either, I really don't know what is going on.

Defohin

This post is deleted!

m.sue

Hi,
please try to make QNetworkReply *reply a class member variable. As you have it now it gets lost as soon as you leave the function. You will need it anyway in the readyReadslot.
-Michael.

Defohin

The problem was on the instance of the class, I had to use it as a pointer.

auto nytimes = new NYTimes;
nytimes->parse();

instead of:

NYTimes nytimes;
nytimes.parse();

Is there a reason for that?

mrjj

Hi
It depends on the context

void Func() {
auto nytimes = new NYTimes;
nytimes->parse();
} // after here NYTimes still lives

void Func() {
NYTimes nytimes;
nytimes.parse();
} // after here NYTimes is no more

Defohin

I was calling NYTimes nytimes; on the constructor of the QMainWindow

mrjj

@Defohin said in QNetworkAccessManager signals not working:

NYTimes nytimes; on the constructor of the QMainWindow

So it means that at the time when
MainWindow was shown, nytimes would have been deleted.
Its called "running out of scope". Applies to all variables on the stack.

Defohin

Thank you, it's solved