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// Copyright (C) 2018 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GFDL-1.3-no-invariants-only

/*!
    \example quicksubscription
    \title Qt Quick Subscription
    \examplecategory {Connectivity}
    \ingroup qtmqtt-examples
    \brief Use Qt Quick Controls to create an application that can subscribe to MQTT
    topics.

    \image quicksubscription.png

    \e {Qt Quick Subscription} demonstrates how to register QMqttClient as a QML type and
    use it in a Qt Quick application.

    \l {Qt MQTT} does not provide a QML API in its current version. However,
    you can make the C++ classes of the module available to QML.

    \section1 Creating a Client

    Connect to QMqttSubscription::messageReceived( ) to receive all messages
    sent to the broker:

    \quotefromfile quicksubscription/qmlmqttclient.cpp
    \skipto QmlMqttSubscription
    \printuntil }

    Create a \c QmlMqttClient class with the QMqttClient class as a base
    class:

    \skipto QmlMqttClient(
    \printuntil }

    Use the \c subscribe() function to create a subscription object:
    \skipto subscribe
    \printuntil }

    Use a QMqttMessage object to store the payload of a received
    message:

    \skipto handleMessage
    \printuntil }

    \section1 Registering Classes in QML

    In the \c main.cpp file, load the QML type Main from the module
    subscription:

    \quotefromfile quicksubscription/main.cpp
    \skipto (argc
    \printuntil loadFromModule

    Now use the MqttClient type in the \c Main.qml file to create an
    MQTT client:

    \quotefromfile quicksubscription/Main.qml
    \skipto MqttClient {
    \printuntil }
*/