Problem with compile class with QObject

Creatorczyk

Hi,

I have created the MqttClient class. While building the program, got strange errors, including "undefined reference to 'vtable for QMqttClient". I solved the problem by clicking:
"Clean all" -> "Run qmake" -> "Build all"
The program was building. Unfortunately, when I create an MqttClient object in main cpp, I get a lot of errors (35) starting with "undefined reference to 'QMqttClient::......"
For example:

error: undefined reference to `QMqttClient::QMqttClient(QObject*)'
error: undefined reference to `QMqttTopicFilter::~QMqttTopicFilter()'
error: undefined reference to `vtable for QMqttClient'

/home/jakub/raspi/qt5pi/include/QtCore/qobject.h:269: error: undefined reference to `QMqttClient::staticMetaObject'

error: undefined reference to `QMqttClient::qt_metacast(char const*)'
error: undefined reference to `typeinfo for QMqttClient'

Another "Clean all" -> "Run qmake" -> "Build all" doesnt fix the errors. I also tried removing the moc files from the build folder and it didnt help. What can I do?

Below is my class and pro file (I'm using cross compilation for RPi4)

Header:

#ifndef MQTTCLIENT_H
#define MQTTCLIENT_H

#include <QtMqtt/QMqttClient>
#include <QtMqtt/QMqttSubscription>
#include "../UserApp/config.h"

class MqttClient : public QMqttClient
{
    Q_OBJECT
public:
    MqttClient(QObject *parent = nullptr);
    ~MqttClient(){}

private:
    QMqttClient *m_mqttClient;

signals:
    void newMotorsCommand(MotorsCommand &motorsCommand);

private slots:
    void slotErrorChanged(const QMqttClient::ClientError e);
    void slotStateChanged();
    void slotDisconnected();
    void slotConnected();
};

#endif // MQTTCLIENT_H

CPP file:

#include "mqttclient.h"

MqttClient::MqttClient(QObject *parent) : QMqttClient(parent)
{
    m_mqttClient = new QMqttClient();

    if (m_mqttClient) {
      m_mqttClient->setHostname("localhost");
      m_mqttClient->setPort(1883);
      m_mqttClient->setUsername("guest");
      m_mqttClient->setPassword("guest");

      connect(m_mqttClient, &QMqttClient::stateChanged, this, &MqttClient::slotStateChanged);
      connect(m_mqttClient, &QMqttClient::disconnected, this, &MqttClient::slotDisconnected);
      connect(m_mqttClient, &QMqttClient::connected, this, &MqttClient::slotConnected);
      connect(m_mqttClient, &QMqttClient::errorChanged, this, &MqttClient::slotErrorChanged);

      m_mqttClient->connectToHost();
    }
}

void MqttClient::slotConnected()
{
  qDebug() << Q_FUNC_INFO;

  auto sub = m_mqttClient->subscribe(QMqttTopicFilter(MQTT::TRUCK::MOTORS_TOPIC), 0);

  m_mqttClient->connect(sub, &QMqttSubscription::messageReceived, [this](const QMqttMessage &message) {});
}

void MqttClient::slotDisconnected()
{
  qDebug() << Q_FUNC_INFO;
}

void MqttClient::slotStateChanged()
{
  const QString content = QDateTime::currentDateTime().toString()
      + QLatin1String(": State Change : ")
      + QString::number(m_mqttClient->state());
  qDebug() << Q_FUNC_INFO << content;
}

void MqttClient::slotErrorChanged(const QMqttClient::ClientError e)
{
  if (e == QMqttClient::NoError) {
    return;
  }

  qDebug() << Q_FUNC_INFO;
  switch (e) {
    case QMqttClient::NoError                :  qDebug() << "NoError"; break;
    case QMqttClient::InvalidProtocolVersion :  qDebug() << "InvalidProtocolVersion";break;
    case QMqttClient::IdRejected             :  qDebug() << "IdRejected";break;
    case QMqttClient::ServerUnavailable      :  qDebug() << "ServerUnavailable";break;
    case QMqttClient::BadUsernameOrPassword  :  qDebug() << "BadUsernameOrPassword";break;
    case QMqttClient::NotAuthorized          :  qDebug() << "NotAuthorized";break;
    case QMqttClient::TransportInvalid       :  qDebug() << "TransportInvalid";break;
    case QMqttClient::ProtocolViolation      :  qDebug() << "ProtocolViolation";break;
    case QMqttClient::UnknownError           :  qDebug() << "UnknownError"; break;
    case QMqttClient::Mqtt5SpecificError     :  qDebug() << "Mqtt5SpecificError";break;
  }

  qWarning() << "Error Occurred:" << e << " Client state :" << m_mqttClient->state();
  m_mqttClient->disconnectFromHost();
}

PRO:

QT -= gui mqtt

CONFIG += c++11 console
CONFIG -= app_bundle

DEFINES += QT_DEPRECATED_WARNINGS

INCLUDEPATH += /home/jakub/raspi/sysroot/usr/include/

LIBS += -L"/home/jakub/raspi/sysroot/usr/lib"
LIBS += -lwiringPi -lpthread

SOURCES += \
        main.cpp \
        mqtt/mqttclient.cpp

HEADERS += \
    ../common/msg_structures.h \
    mqtt/mqttclient.h

target.path = /home/pi/UDES/bin
INSTALLS += target

SGaist

Hi,

You explicitly disable the gui and mqtt modules in your .pro file.

Creatorczyk

@SGaist It's works! Thank you!