What does the method Connect do in websockets programming?

Mohankumar_S

I am facing difficulty in understanding the following code snippet
connect(&m_webSocket, &QWebSocket::connected, this, &qtWebSocketClient::onConnected);

Can somebody explain what is happening here?

I am trying to control the connect,send,rcv aspects of the client - server application externally.

koahnig

@Mohankumar_S

You should have a look to signal and slots
The connect routine is connecting the signal QWebSocket::connected to the slot qtWebSocketClient::onConnected.

The naming becomes a bit fusing when a signal is connected to something which reports basically the success of a completely unrelated connection (e.g. within the internet).

Lineaxe

Also I believe you do have an object of the m_webSocket class created , and this is set to the current class (for me a lot of the time that is the mainwindow class). So the ' &QWebSocket::connected SIGNAL comes from the m_webSocket class '
and the ' &qtWebSocketClient::onConnected SLOT comes from this (the current class object) '.

Mohankumar_S

@koahnig Thank you

Mohankumar_S

@koahnig How to serve multiple client requests through a single server?

koahnig

@Mohankumar_S

It may depend on the server implementation. Especially you need to check the web socket protocol. I have no experience there.

In general you can send a couple of requests subsequently and wait for the corresponding replies. If the server does not maintain a stack for requests, you have to wait for each reply and send the next request. However, this is dependent on the server implementation.

Have a look to the websocket examples. There might be one already close to what you try to do.

Mohankumar_S

@koahnig Thank you

Mohankumar_S

@koahnig I am getting the following linking error
/home/mohan/QtWebSocketServer/qtwebsocketserver.cpp:-1: error: undefined reference to QHostAddress::QHostAddress(QHostAddress::SpecialAddress)' /home/mohan/QtWebSocketServer/qtwebsocketserver.cpp:-1: error: undefined reference to QWebSocketServer::listen(QHostAddress const&, unsigned short)'
/home/mohan/QtWebSocketServer/qtwebsocketserver.cpp:-1: error: undefined reference to `QWebSocketServer::newConnection()'

These are my include files
#include "qtwebsocketserver.h"
#include "QtWebSockets/qwebsocketserver.h"
#include "QtWebSockets/qwebsocket.h"
#include <QtCore/QDebug>
QTime t;
QT_USE_NAMESPACE

This is my project file
QT += core
QT -= gui

CONFIG += c++11

TARGET = QtWebSocketServer
CONFIG += console
CONFIG -= app_bundle

TEMPLATE = app

SOURCES += main.cpp
qtwebsocketserver.cpp
iwebsocketserver.cpp
cwebsocketserver.cpp

SUBDIRS +=
echoclient.pro

DISTFILES +=
echoclient.pro.user
echoclient.html

HEADERS +=
qtwebsocketserver.h
iwebsocketserver.h
cwebsocketserver.h

jsulm

As the documentation says you need this line in your pro file in order to use network functionality:

QT += network