How can you send complex objects with sockets?

danga96

hello to the whole community Qt Forum,
I have a question, I'm developing a client / server application and I would like to know if there are socket (qt) functions capable of sending complex objects of variable size, but note when sending.
Obviously the receiver will also know the size;
Thanks in advance

aha_1980

Hi @danga96,

you should look up QDataStream which allows exactly this.

Regards

VRonin

Another alternative is to use JSON or the more recently added CBOR directly on the device

danga96

@aha_1980
Thank you for your reply; only that I need to send an object through a socket, not through a file ... I know they are very similar, but I would like to find, a class that does this right :)

fcarney

@danga96 said in How can you send complex objects with sockets?:

I need to send an object through a socket, not through a file

#include <QCoreApplication>
#include <QDebug>
#include <QDataStream>
#include <QByteArray>

struct complex_object{
    QString m_string;
    float m_float;
    int m_int;
};

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

    complex_object cp;
    cp.m_string = "Some 💩";
    cp.m_float = 0.666;
    cp.m_int = 42;

    qInfo() << "before send:" << cp.m_string << cp.m_float << cp.m_int;

    QByteArray data; // used by socket stuff to hold data
    QDataStream sdata(&data, QIODevice::WriteOnly);
    sdata << cp.m_string << cp.m_float << cp.m_int;

    qInfo() << "... magically floating through cyberspace via sockets";

    complex_object cp2;
    QDataStream rdata(&data, QIODevice::ReadOnly);
    rdata >> cp2.m_string >> cp2.m_float >> cp2.m_int;

    qInfo() << "after receive:" << cp2.m_string << cp2.m_float << cp2.m_int;

    return a.exec();
}

I like puppies and kittens... (reference to show that describes "knowing your place", and yes, totally random)

aha_1980

@danga96

Thank you for your reply; only that I need to send an object through a socket, not through a file

Everything is a file in Unix, and everything a QIODevice in Qt.

Regards

fcarney

@aha_1980 said in How can you send complex objects with sockets?:

Everything is a file in Unix, and everything a QIODevice in Qt.

So say we all...