QWebSocket wont connect or give error

mrjj

@Kris-Revi said in QWebSocket wont connect or give error:

void connectTo()
{
MySocket client(QUrl(QStringLiteral("ws://192.168.10.122:80")), true);
}

Hi
But wont the client die very fast ?
Since its async, it might not get a chance to report anything as it runs out of scope and gets deleted.

Kris Revi

@mrjj i am not sure! first time touching Qt C++ ! i've done this in PyQt5 Python but yea

it doesn't seem to connect at all! it just spits out the qDebug message WebSocket server: QUrl("ws://192.168.10.122:80")

mrjj

@Kris-Revi
Hi
well since its a variable in a function it will be deleted as soon as function ends.
So that might happen really fast before it get chance to signal anything else.

Try having
MySocket client; as a member and not as a local variable.
and see if that helps.

you can also do
void connectTo()
{
MySocket* client= new MySocket (QUrl(QStringLiteral("ws://192.168.10.122:80")), true);
}

but its a memory leak but fine to test if that is indeed the issue.
(killed by scope)

JonB

@Kris-Revi said in QWebSocket wont connect or give error:

@mrjj i am not sure! first time touching Qt C++ ! i've done this in PyQt5 Python but yea

In your PyQt5, did you do same client = MySocket (...) where client was just a local label in a method; or did you do a self.client = MySocket (...), or pass a parent? Because @mrjj is right, and you will have to be even more careful about scope in C++ than in Python....

Kris Revi

@JonB yea i did self.client so yea difference here is local vs class member :P

so i added MySocket Socket; to mainwindow.h header file

but how do i now call that

MySocket client(QUrl(QStringLiteral("ws://%1:80").arg(selected_board)), true);

if i do

Socket(QUrl(QStringLiteral("ws://%1:80").arg(selected_board)), true);

i get type 'MySocket' does not provide a call operator

Kris Revi

so i did it like this

// =========================================================================================================== //
// CONSTRUCTOR
// =========================================================================================================== //
MySocket::MySocket(QObject *parent) : QObject(parent)
{
    connect(&m_webSocket, &QWebSocket::connected, this, &MySocket::onConnected);
    connect(&m_webSocket, &QWebSocket::disconnected, this, &MySocket::closed);
    connect(&m_webSocket, QOverload<QAbstractSocket::SocketError>::of(&QWebSocket::error), [=](QAbstractSocket::SocketError error)
    {
       qDebug() << "[ERROR][SOCKET] " << error;
    });
    
}

// =========================================================================================================== //
// Socket Connected
// =========================================================================================================== //
void MySocket::doConnect(QString URL)
{
    qDebug() << "WebSocket server:" << URL;
    m_webSocket.open(QUrl(URL));
}

i moved the .open part to it's own function and called it from Socket.doConnect(selected_board);

but i get an error (atleast something)

WebSocket server: "192.168.10.122"
[ERROR][SOCKET]  QAbstractSocket::UnsupportedSocketOperationError

Kris Revi

@mrjj you know? :)

mrjj

@Kris-Revi
Hi
It can say this error if you ask it to do something while connecting state but i dont see code that would do it.

Kris Revi

@mrjj so what i do is this (keep in mind the code above)

void MainWindow::findIP(QString Key)
{
    auto key = Key;
        if ( board.count(key) ) {
            DeviceInfo &di = board[key];
            connectTo( di.ip );
        }
        else
        {
            qDebug() << "[ERROR][STRUCT] Did not find key using the word : " << Key;
        }
}

// This is a button bind on clicked (one of the Devices) triggers the function above
void MainWindow::on_BUTTON_STUDIOLIGHT_clicked() { findIP("Studio Lights"); }

// This is function that gets called from findIP function todo the connection with socket
void MainWindow::connectTo(QString selected_board)
{
    Socket.doConnect(selected_board);
}

and this is the MySocket.cpp file

// =========================================================================================================== //
// INCLUDE
// =========================================================================================================== //
#include "MySocket.h"
#include <QDebug>

QT_USE_NAMESPACE

// =========================================================================================================== //
// CONSTRUCTOR
// =========================================================================================================== //
MySocket::MySocket(QObject *parent) : QObject(parent)
{
    connect(&m_webSocket, &QWebSocket::connected, this, &MySocket::onConnected);
    connect(&m_webSocket, &QWebSocket::disconnected, this, &MySocket::closed);
    connect(&m_webSocket, QOverload<QAbstractSocket::SocketError>::of(&QWebSocket::error), [=](QAbstractSocket::SocketError error)
    {
       qDebug() << "[ERROR][SOCKET] " << error;
    });
    
}

// =========================================================================================================== //
// Socket Connected
// =========================================================================================================== //
void MySocket::doConnect(QString URL)
{
    qDebug() << "WebSocket server:" << URL;
    m_webSocket.open(QUrl(URL));
}
// =========================================================================================================== //
// Socket On Connected
// =========================================================================================================== //
void MySocket::onConnected()
{
    if (m_debug)
        qDebug() << "WebSocket connected";
}
// =========================================================================================================== //
// Send Message (For Strips)
// =========================================================================================================== //
void MySocket::sendCommandStrip(const QString &bName, int bValue)
{
    m_webSocket.sendTextMessage(QStringLiteral("{%0:%1}").arg(bName).arg(bValue));
}
// =========================================================================================================== //
// Send Message (For Matrix)
// =========================================================================================================== //
void MySocket::sendCommandMatrix(QString bValue)
{
    m_webSocket.sendTextMessage(bValue);
}
// =========================================================================================================== //
// Socket Close
// =========================================================================================================== //
void MySocket::close()
{
    m_webSocket.close();
}

mrjj

Hi
It looks fine but i wonder i QUrl likes an IP as that is what you give it.
Also those IPs. could that request HTTPS so that you need SSL compiled and enabled ?

Kris Revi

@mrjj i found out why!

Original :

Socket.doConnect(selected_board);

Now :

Socket.doConnect(QStringLiteral("ws://%1:80").arg(selected_board));

Kris Revi

@mrjj how do i do this in Qt C++

Python (custom Qt Signal)

error = pyqtSignal(QtNetwork.QAbstractSocket.SocketError)

so that i can hookup error and connected signal to slots in mainwindow.cpp :)

Kris Revi

I've put onError and onConnected under Q_SIGNALS: in the MySocket.h in the class!

now what?

mrjj

@Kris-Revi

Hi
Then you have defined 3 new signals for your class.
Another class could now use the connect statement to
hook up a slot to your new signals.

However, for something to happen.
You must use

emit onConnected();

somewhere in your code to actually "send" the signal
at the right times.