// Copyright (C) 2016 basysKom GmbH, author Bernd Lamecker <bernd.lamecker@basyskom.com>
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause

/*!
    \example chatserver-cpp
    \title Qt WebChannel ChatServer Example
    \ingroup qtwebchannel-examples
    \brief A simple chat server implemented using the QWebChannel C++ API.

    \image chatserver-cpp.png

    \e{ChatServer} provides a chat service that the
    \l{Qt WebChannel ChatClient QML Example} and
    \l{Qt WebChannel ChatClient HTML Example} can connect to.

    \include examples-run.qdocinc

    \section1 Implementing a Chat Server

    The C++ application implements a QObject which provides all mechanisms required for
    a chat service.
    This object is published through a QWebChannel which uses a \l{Qt WebSockets}
    {WebSocket} as transport.

    The server provides a basic \c login method (username only, no passwords), which must be
    successfully invoked before a client is able to chat.
    After login, a client can invoke the method \c sendMessage and receive the signal \c newMessage
    to write and receive messages. Furthermore, there is a \c userList property which provides
    the names of all other connected clients.
    Additionally the server sends a \c keepAlive signal periodically to all clients. The clients
    have to respond to this signal, otherwise the client will be removed from the \c userList property.

    The example shows how basic QObject elements can be used with QWebChannel, that is signals
    (\c newMessage), slots (\c sendMessage), and properties (\c userList).

    Because this is a plain server application, separate clients are needed to
    interact with it. \l{Qt WebChannel ChatClient QML Example} and
    \l{Qt WebChannel ChatClient HTML Example} are client implementations
    compatible with this server.

*/