QWebSocket client example

Description

The EchoClient example implements a WebSocket client that sends a message to a WebSocket server and dumps the answer that it gets back. This example should ideally be used with the EchoServer example.

Code

We start by connecting to the `connected()` signal.

 EchoClient::EchoClient(const QUrl &url, bool debug, QObject *parent) :
     QObject(parent),
     m_debug(debug)
 {
     if (m_debug)
         qDebug() << "WebSocket server:" << url;
     connect(&m_webSocket, &QWebSocket::connected, this, &EchoClient::onConnected);
     connect(&m_webSocket, &QWebSocket::disconnected, this, &EchoClient::closed);
     m_webSocket.open(url);
 }

After the connection, we open the socket to the given url.

 void EchoClient::onConnected()
 {
     if (m_debug)
         qDebug() << "WebSocket connected";
     connect(&m_webSocket, &QWebSocket::textMessageReceived,
             this, &EchoClient::onTextMessageReceived);
     m_webSocket.sendTextMessage(QStringLiteral("Hello, world!"));
 }

When the client is connected successfully, we connect to the `onTextMessageReceived()` signal, and send out "Hello, world!". If connected with the EchoServer, we will receive the same message back.

 void EchoClient::onTextMessageReceived(QString message)
 {
     if (m_debug)
         qDebug() << "Message received:" << message;
     m_webSocket.close();
 }

Whenever a message is received, we write it out.