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// Copyright (C) 2016 basysKom GmbH, author Bernd Lamecker <bernd.lamecker@basyskom.com>
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR BSD-3-Clause
/*!
\example chatclient-qml
\title Qt WebChannel ChatClient QML Application
\ingroup qtwebchannel-examples
\brief A QML client that communicates over a WebSocket with a QWebChannel server.
\examplecategory {Input/Output}
\meta tag {rpc,network}
\image chatclient-qml.png
\e{ChatClient QML} provides a simple QWebChannel client implemented using JavaScript and QML.
\section1 Implementing a Web Channel Client in QML
This example shows how you can use the basic elements with the client JavaScript
implementation of QWebChannel, like connecting to signals (\c newMessage),
calling slots (\c sendMessage), and handling property changes (\c userList).
The client initializes a \l [QML] WebSocket connection to the chat server at port
12345 on localhost. When the WebSocket opens, a WebChannel object is created, taking
the WebSocket as first argument and a callback function as the second argument. When
the callback is called, the client receives an object named \c chatserver,
containing all the necessary signals, slots, and properties for implementing a chat
client. The callback function connects \c userListChanged, \c newMessage, and
\c keepAlive on the \c chatserver object with separate functions handling those
signals, and then it calls \c show on \c loginWindow.
The \c Window with \c loginWindow as id handles the login procedure. It contains a
\c LoginForm defined in LoginForm.ui.qml. When you press the button, it calls
the \c login function on the \c chatserver object with the login name and and a
callback function as arguments. This callback function handles both if the login
succeeds or fails.
After login, the client uses a \c MainForm, defined in MainForm.ui.qml, with
\c mainUi as id, to post messages using the \c sendMessage slot, read messages
using the \c newMessage signal, and to view the names of all connected users
using the \c userList property. Also, the client responds to the server's
\c keepAlive signal in order for the server to detect disconnected clients
and remove them from the \c userList property.
The client is able to work with the \l{Qt WebChannel ChatServer Example}.
\sa {Qt WebChannel ChatServer Example}, {Qt WebChannel ChatClient HTML Example}
*/
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