Cannot get data from HTTP request

t0msk

Hello,

this is my code:

QSslConfiguration config = QSslConfiguration::defaultConfiguration();
config.setProtocol(QSsl::TlsV1_2);
QNetworkAccessManager *manager = new QNetworkAccessManager();
QNetworkRequest request;
QNetworkReply *reply = NULL;
    
request.setHeader(QNetworkRequest::ServerHeader, "application/json");
request.setSslConfiguration(config);
request.setUrl(QUrl("https://www.archlinux.org/packages/search/json/?q=dolphin"));

connect(manager, SIGNAL(finished(QNetworkReply*)), this, SLOT(replyFinished(QNetworkReply*)));

And this is callback function for reply:

void Manager::replyFinished(QNetworkReply *reply)
{
    qDebug() << reply->readAll();

    QString test = reply->readAll();
}

Problem is that, if I debug it I don't jump into replyFinished function, it looks like connect doesn't call that function, can you help me, where is problem?

Thank you

SGaist

Hi,

You're not connecting any of the error related signals. You should add that to your code.

ODБOï

@t0msk hi
are you posting the request?

mrjj

Hi
I dont see any
manager->get(request);
or similar to actually run the Request.

Also, you are using HTTPS so did you install the
OpenSSL 1.0.2 and put it in a PATH that your app can find?
(or next to the app in the build folder)

Note:
5.12.4 Released with support for OpenSSL 1.1.1
https://www.qt.io/blog/2019/06/17/qt-5-12-4-released-support-openssl-1-1-1

Try to add
qDebug() << QSslSocket::supportsSsl();
qDebug() << QSslSocket::sslLibraryBuildVersionString();

and see if it say TRUE or FALSE
and it will also list the openSSL Lib it supports.
like
"OpenSSL 1.1.1b 26 Feb 2019"

t0msk

I changed code like this:

    QSslConfiguration config = QSslConfiguration::defaultConfiguration();
    config.setProtocol(QSsl::TlsV1_2);
    QNetworkAccessManager *manager = new QNetworkAccessManager();
    QNetworkRequest request;
    QNetworkReply *reply = NULL;

    request.setHeader(QNetworkRequest::ServerHeader, "application/json");
    request.setSslConfiguration(config);
    request.setUrl(QUrl("https://www.archlinux.org/packages/search/json/?q=dolphin"));

    manager->get(request);

    connect(manager, SIGNAL(finished(QNetworkReply*)), this, SLOT(replyFinished(QNetworkReply*)));

    connect(manager, SIGNAL(error(QNetworkReply*)), this, SLOT(replyFinished(QNetworkReply*)));

    connect(manager, SIGNAL(sslErrors(QNetworkReply*)), this, SLOT(replyFinished(QNetworkReply*)));

And still during debugging I dont stop in replyFinsihed function.

SGaist

You should move the Qt 5 new syntax. It would have show you that error is not part of QNetworkAccessManager and that the signature of ssErrors is wrong.

t0msk

@SGaist said in Cannot get data from HTTP request:

You should move the Qt 5 new syntax. It would have show you that error is not part of QNetworkAccessManager and that the signature of ssErrors is wrong.

Which syntax? I use Qt5.

I tried even:

    QNetworkReply *reply = manager->get(request);

    connect(reply, SIGNAL(finished(reply)), this, SLOT(replyFinished(reply)));

    connect(reply, SIGNAL(error(reply)), this, SLOT(replyFinished(reply)));

    connect(reply, SIGNAL(sslErrors(reply)), this, SLOT(replyFinished(reply)));

mrjj

@t0msk
Hi
The SIGNAL and SLOT macros is the "old way"
its explained here
https://wiki.qt.io/New_Signal_Slot_Syntax

The main benefit is that it gives errors at compile time if its not correct.
The SIGNAL and SLOT will eat most things and not complain but simply
fail to work at runtime.

t0msk

So I tried this:

connect(
        reply, &reply::finished,
        this, &Manager::replyFinished
    );

And I get:

error: 'reply' is not a class, namespace, or enumeration

I quite don't understand what to put into &reply yet :)

SGaist

The name of the class containing the signal, same goes for the last parameter, it's the name of the class containing the slot.

t0msk

@SGaist

Changed it to this:

connect(
        reply, &QNetworkReply::finished,
        this, &Manager::replyFinished
    );

And I get:

/usr/include/qt/QtCore/qobject.h:243: error: static assertion failed: The slot requires more arguments than the signal provides.
  243 |         Q_STATIC_ASSERT_X(int(SignalType::ArgumentCount) >= int(SlotType::ArgumentCount),
      |         ^~~~~~~~~~~~~~~~~

mrjj

@t0msk said in Cannot get data from HTTP request:

QNetworkReply::finished,

Well you are mixing the classes/signals.
The reply's signals is
https://doc.qt.io/qt-5/qnetworkreply.html#finished
and have no QNetworkReply* parameter.

so i think you mean

connect(
        Manager, &QNetworkAccessManager::finished,
        this, &Manager::replyFinished
    );

t0msk

@mrjj said in Cannot get data from HTTP request:

@t0msk said in Cannot get data from HTTP request:

QNetworkReply::finished,

Well you are mixing the classes.
The reply signals is
https://doc.qt.io/qt-5/qnetworkreply.html#finished
and have no QNetworkReply* parameter.

so i think you mean
connect(
        Manager, &QNetworkAccessManager::finished,
        this, &Manager::replyFinished
    );

Thank you,
so now I have:

    QSslConfiguration config = QSslConfiguration::defaultConfiguration();
    config.setProtocol(QSsl::TlsV1_2);
    QNetworkAccessManager *manager = new QNetworkAccessManager();
    QNetworkRequest request;


    request.setHeader(QNetworkRequest::ServerHeader, "application/json");
    request.setSslConfiguration(config);
    request.setUrl(QUrl("https://www.archlinux.org/packages/search/json/?q=dolphin"));

    QNetworkReply *reply = manager->get(request);

    connect(
        manager, &QNetworkAccessManager::finished,
        this, &Manager::replyFinished
    );

    connect(
        manager, &QNetworkAccessManager::sslErrors,
        this, &Manager::replyFinished
    );

void Manager::replyFinished(QNetworkReply *reply)
{
    qDebug() << reply->readAll();

    QString ha = reply->readAll();

    QString he;
}

Still no output and no error :/

mrjj

Hi
Its a bit odd to connect all to the same slot but lets leave it for now.

now its time to
check your openSSL support !

what does
qDebug() << "i can use HTTPS:" << QSslSocket::supportsSsl();
qDebug() << "version" << QSslSocket::sslLibraryBuildVersionString();

say ?

t0msk

@mrjj
It says:

i can use HTTPS: true
version "OpenSSL 1.1.1c  28 May 2019"

SGaist

What version of Qt are you using ?

One more thing: do these connections prior to calling get.

t0msk

@SGaist Qt version is 5.13.1

t0msk

So where can be problem? :/

SGaist

Did you move the connection statements as I suggested ?

t0msk

@SGaist I dont know what do you mean