QRemoteObject Tcp examples

[Addam]

I'm trying to follow the External QIODevices examples, but it's missing to demonstrate how the srcNodes are being enabled and the replicas acquired.

I cant get the first example working, I tried:

.rep

class RemoteObject
{
    SLOT(void test(QString str))
    SIGNAL(signalTest(int x))
};

remoteobject.h

#include "rep_remoteobject_source.h"
class RemoteObject : public RemoteObjectSource
{
    Q_OBJECT
public:
public slots:
    void test(QString str) {
        qDebug() << "str:" << str;
    }
};

#include <QNetworkReply>
#include <QRemoteObjectHost>
#include <QTcpServer>
#include "remoteobject.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    QTcpServer tcpServer;
    tcpServer.listen(QHostAddress(QStringLiteral("127.0.0.1")), 65213);

    QRemoteObjectHost srcNode;
    QObject::connect(&tcpServer, &QTcpServer::newConnection, &srcNode, [&] {
        srcNode.addHostSideConnection(tcpServer.nextPendingConnection());
    });

    RemoteObject remoteObject;
    bool ret = srcNode.enableRemoting(&remoteObject, "remoteObject");
    qDebug() << "enableRemoting:" << ret << srcNode.lastError();
    return a.exec();
}

srcNode.enableRemoting is returning false, lastError: QRemoteObjectNode::OperationNotValidOnClientNode.

In the enableRemoting documentation says: "Returns false if the current node is a client node"

And in the example there's a comment:

// Create the host node. We don't need a hostUrl unless we want to take

// advantage of external schemas (see next example).

Without a hostUrl set in the srcNode, it's probably being threatened as a client?

Am I not understanding it correctly or is something missing from the example?

---

---

---

The second example compile, but some things:

• The client don't get the signal from the host.
• When I try to acquire the replica it fails: qt.remoteobjects: connectionToSource is null
• When the host close, the client connected to it crashes.

-EDIT-

After investigating more, I got some points about the crash
https://doc.qt.io/qt-6/qabstractsocket.html#disconnected

"Warning: If you need to delete the sender() of this signal in a slot
connected to it, use the deleteLater() function."

In the example it call delete socket on error, which also get triggered when the host is closed...

host

#include <QNetworkReply>
#include <QRemoteObjectHost>
#include <QTcpServer>
#include "remoteobject.h"

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);

    const QUrl registryUrl = QUrl(QStringLiteral("tcp://127.0.0.1:65212"));
    const QUrl extUrl = QUrl(QStringLiteral("exttcp://127.0.0.1:65213"));

    QTcpServer tcpServer;
    tcpServer.listen(QHostAddress(extUrl.host()), extUrl.port());
    QRemoteObjectRegistryHost registry(registryUrl);

    QRemoteObjectHost srcNode(extUrl, registryUrl, QRemoteObjectHost::AllowExternalRegistration);
    RemoteObject remoteObject;
    ret = srcNode.enableRemoting(&remoteObject, "remoteObject");
    qDebug() << "enableRemoting:" << ret;

    int x = 0;
    QTimer* timer = new QTimer();

    QObject::connect(timer, &QTimer::timeout, [&]() {
        qDebug() << "x:" << x;
        emit remoteObject.signalTest(x);
        x++;
    });
    timer->start(1000);
    return a.exec();
}

client

#include <QRemoteObjectNode>
#include <QTcpSocket>
#include <QSslSocket>
#include "rep_remoteobject_replica.h"

int main(int argc, char* argv[])
{
    QApplication a(argc, argv);

    const QUrl registryUrl = QUrl(QStringLiteral("tcp://127.0.0.1:65212"));
    QRemoteObjectNode repNode(registryUrl);
    QRemoteObjectNode::RemoteObjectSchemaHandler setupTcp = [&repNode](QUrl url)
    {
        QTcpSocket* socket = new QTcpSocket(&repNode);
        QObject::connect(socket, &QTcpSocket::connected, [socket, &repNode]()
        {
            qDebug() << "connected...";
            repNode.addClientSideConnection(socket);

            QSharedPointer<RemoteObjectReplica> ptr;
            ptr.reset(repNode.acquire<RemoteObjectReplica>("remoteObject_2"));  // <---- error: qt.remoteobjects: connectionToSource is null

            ptr.data()->test("hello world");

        });
        QObject::connect(socket, &QSslSocket::errorOccurred, [socket](QAbstractSocket::SocketError error) {
            qDebug() << "error:" << error;
            delete socket;
        });

        qDebug() << "setupTcp...";
        socket->connectToHost(url.host(), url.port());
    };

    repNode.registerExternalSchema(QStringLiteral("exttcp"), setupTcp);

    QSharedPointer<RemoteObjectReplica> ptr;
    ptr.reset(repNode.acquire<RemoteObjectReplica>("remoteObject_2"));   // <---- im probably doing something wrong here?
                                                                         // and in the example dont demonstrate how to acquire the replica

    QObject::connect(ptr.data(), &RemoteObjectReplica::signalTest, &a, [](int x) {
        qDebug() << "x:" << x; // <---- never called
    });

    return a.exec();
}