receive data from client via QTcpServer

[Fallen_]

Hi, I made a simple chat server, but can't get it working to receive data from the client (incoming connection)
heres my code:
server.h:

#ifndef SERVER_H
#define SERVER_H
 
#include <QDialog>
 
class QTcpServer;
class QLabel;
class QPushButton;
class QTextEdit;
 
class Server : public QDialog
{
	Q_OBJECT
	public:
		Server(QWidget* parent = 0);
 
	private slots:
		void sendWelcomeMessage();
 
	private:
		QLabel* status;
		QPushButton* quit;
		QTcpServer* server;
		QTextEdit* read;
};
#endif

#ifndef SERVER_H
#define SERVER_H

#include <QDialog>

class QTcpServer;
class QLabel;
class QPushButton;
class QTextEdit;

class Server : public QDialog
{
	Q_OBJECT
	public:
		Server(QWidget* parent = 0);

	private slots:
		void sendWelcomeMessage();

	private:
		QLabel* status;
		QPushButton* quit;
		QTcpServer* server;
		QTextEdit* read;
};
#endif

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server.cpp

#include <QtGui>
#include <QtNetwork>
#include "server.h"
 
Server::Server(QWidget* parent)
	: QDialog(parent)
{
	status = new QLabel;
	quit = new QPushButton(tr("&Close"));
	connect(quit, SIGNAL(clicked()), this, SLOT(close()));
	server = new QTcpServer(this);
	read = new QTextEdit(tr("Status:\n"));
	read->setReadOnly(true);
	QHostAddress addr("127.0.0.1");
 
	if(!server->listen(addr, 12345)) {
		QMessageBox::information(this, tr("Error!!"), tr("The following errors has occured: %1").arg(server->errorString()));
		return;
	}
 
	status->setText(tr("The server is running on %1 port.").arg(server->serverPort()));
	connect(server, SIGNAL(newConnection()), this, SLOT(sendWelcomeMessage()));
 
	QHBoxLayout* layout = new QHBoxLayout;
	layout->addWidget(status);
	layout->addWidget(quit);
	layout->addWidget(read);
	setLayout(layout);
}
 
void Server::sendWelcomeMessage()
{
	typedef QVector<QTcpSocket*> Connections;
	Connections connections;
	QTcpSocket *client = server->nextPendingConnection();
	connect(client, SIGNAL(disconnected()), client, SLOT(deleteLater()));
	client->write("Welcome!");
	char buffer[100];
	sprintf(buffer, "Incoming connection from IP: %s", client->peerAddress().toString().toStdString().c_str());
	read->append(buffer);
	connections.push_back(client);
	for(Connections::Iterator it = connections.begin(); it != connections.end(); ++it)
		(*it)->write("Hello!!!");
}

#include <QtGui>
#include <QtNetwork>
#include "server.h"

Server::Server(QWidget* parent)
	: QDialog(parent)
{
	status = new QLabel;
	quit = new QPushButton(tr("&Close"));
	connect(quit, SIGNAL(clicked()), this, SLOT(close()));
	server = new QTcpServer(this);
	read = new QTextEdit(tr("Status:\n"));
	read->setReadOnly(true);
	QHostAddress addr("127.0.0.1");

	if(!server->listen(addr, 12345)) {
		QMessageBox::information(this, tr("Error!!"), tr("The following errors has occured: %1").arg(server->errorString()));
		return;
	}

	status->setText(tr("The server is running on %1 port.").arg(server->serverPort()));
	connect(server, SIGNAL(newConnection()), this, SLOT(sendWelcomeMessage()));

	QHBoxLayout* layout = new QHBoxLayout;
	layout->addWidget(status);
	layout->addWidget(quit);
	layout->addWidget(read);
	setLayout(layout);
}

void Server::sendWelcomeMessage()
{
	typedef QVector<QTcpSocket*> Connections;
	Connections connections;
	QTcpSocket *client = server->nextPendingConnection();
	connect(client, SIGNAL(disconnected()), client, SLOT(deleteLater()));
	client->write("Welcome!");
	char buffer[100];
	sprintf(buffer, "Incoming connection from IP: %s", client->peerAddress().toString().toStdString().c_str());
	read->append(buffer);
	connections.push_back(client);
	for(Connections::Iterator it = connections.begin(); it != connections.end(); ++it)
		(*it)->write("Hello!!!");
}

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guess no need for main.cpp.
Well, i tried with client->readLine & client->read both didnt work.
@Edit:
also tried with QTextStream and QDataStream didnt work also.

[tbscope]

You can only read from the socket if there's something to read.
You try to read a nanosecond after you've send the welcom message. In that time, the client didn't have time to respond.

Suggestions:

void Server::sendWelcomeMessage()
{
	typedef QVector<QTcpSocket*> Connections; // <-- Define this at the class level
	Connections connections; // This too
 
                while (server->hasPendingConnections ()) {
                	QTcpSocket *client = server->nextPendingConnection();
	                connect(client, SIGNAL(disconnected()), client, SLOT(deleteLater()));
                                connect(client, SIGNAL(readyRead()), signalmapper, SLOT(map())); // Signal mapper is defined in the class definition and created in the constructor, see QSignalMapper.
                	signalmapper->setMapping(client, client);
	                client->write("Welcome!");
                }
                connect(signalmapper, SIGNAL(mapped(QObject *)), this, SLOT(clientReadyRead(QObject *)));
}
 
void Server::clientReadyRead(QObject *socket)
{
    QTcpSocket *clientSocket = qobject_cast<QTcpSocket *>(socket);
 
    clientSocket->read...()
}

void Server::sendWelcomeMessage()
{
	typedef QVector<QTcpSocket*> Connections; // <-- Define this at the class level
	Connections connections; // This too

                while (server->hasPendingConnections ()) {
                	QTcpSocket *client = server->nextPendingConnection();
	                connect(client, SIGNAL(disconnected()), client, SLOT(deleteLater()));
                                connect(client, SIGNAL(readyRead()), signalmapper, SLOT(map())); // Signal mapper is defined in the class definition and created in the constructor, see QSignalMapper.
                	signalmapper->setMapping(client, client);
	                client->write("Welcome!");
                }
                connect(signalmapper, SIGNAL(mapped(QObject *)), this, SLOT(clientReadyRead(QObject *)));
}

void Server::clientReadyRead(QObject *socket)
{
    QTcpSocket *clientSocket = qobject_cast<QTcpSocket *>(socket);

    clientSocket->read...()
}

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[kapoorsudhish]

Exactly as mentioned, try to read the data on the readyRead() signal for the socket, which ensures that some data is present on the socket and then try to read.

[Fallen_]

You can only read from the socket if there's something to read.
You try to read a nanosecond after you've send the welcom message. In that time, the client didn't have time to respond.

Suggestions:

void Server::sendWelcomeMessage()
{
	typedef QVector<QTcpSocket*> Connections; // <-- Define this at the class level
	Connections connections; // This too
 
                while (server->hasPendingConnections ()) {
                	QTcpSocket *client = server->nextPendingConnection();
	                connect(client, SIGNAL(disconnected()), client, SLOT(deleteLater()));
                                connect(client, SIGNAL(readyRead()), signalmapper, SLOT(map())); // Signal mapper is defined in the class definition and created in the constructor, see QSignalMapper.
                	signalmapper->setMapping(client, client);
	                client->write("Welcome!");
                }
                connect(signalmapper, SIGNAL(mapped(QObject *)), this, SLOT(clientReadyRead(QObject *)));
}
 
void Server::clientReadyRead(QObject *socket)
{
    QTcpSocket *clientSocket = qobject_cast<QTcpSocket *>(socket);
 
    clientSocket->read...()
}

void Server::sendWelcomeMessage()
{
	typedef QVector<QTcpSocket*> Connections; // <-- Define this at the class level
	Connections connections; // This too

                while (server->hasPendingConnections ()) {
                	QTcpSocket *client = server->nextPendingConnection();
	                connect(client, SIGNAL(disconnected()), client, SLOT(deleteLater()));
                                connect(client, SIGNAL(readyRead()), signalmapper, SLOT(map())); // Signal mapper is defined in the class definition and created in the constructor, see QSignalMapper.
                	signalmapper->setMapping(client, client);
	                client->write("Welcome!");
                }
                connect(signalmapper, SIGNAL(mapped(QObject *)), this, SLOT(clientReadyRead(QObject *)));
}

void Server::clientReadyRead(QObject *socket)
{
    QTcpSocket *clientSocket = qobject_cast<QTcpSocket *>(socket);

    clientSocket->read...()
}

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i get this error:
signalmapper was not declared in this scope

[Fallen_]

nvm, i fixed it myself thx