websockettransport.cpp

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** Copyright (C) 2016 Klarälvdalens Datakonsult AB, a KDAB Group company, info@kdab.com, author Milian Wolff <milian.wolff@kdab.com>
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#include "websockettransport.h"

#include <QDebug>
#include <QJsonDocument>
#include <QJsonObject>
#include <QWebSocket>

/*!
    \brief QWebChannelAbstractSocket implementation that uses a QWebSocket internally.

    The transport delegates all messages received over the QWebSocket over its
    textMessageReceived signal. Analogously, all calls to sendTextMessage will
    be send over the QWebSocket to the remote client.
*/

/*!
    Construct the transport object and wrap the given socket.

    The socket is also set as the parent of the transport object.
*/
WebSocketTransport::WebSocketTransport(QWebSocket *socket)
: QWebChannelAbstractTransport(socket)
, m_socket(socket)
{
    connect(socket, &QWebSocket::textMessageReceived,
            this, &WebSocketTransport::textMessageReceived);
    connect(socket, &QWebSocket::disconnected,
            this, &WebSocketTransport::deleteLater);
}

/*!
    Destroys the WebSocketTransport.
*/
WebSocketTransport::~WebSocketTransport()
{
    m_socket->deleteLater();
}

/*!
    Serialize the JSON message and send it as a text message via the WebSocket to the client.
*/
void WebSocketTransport::sendMessage(const QJsonObject &message)
{
    QJsonDocument doc(message);
    m_socket->sendTextMessage(QString::fromUtf8(doc.toJson(QJsonDocument::Compact)));
}

/*!
    Deserialize the stringified JSON messageData and emit messageReceived.
*/
void WebSocketTransport::textMessageReceived(const QString &messageData)
{
    QJsonParseError error;
    QJsonDocument message = QJsonDocument::fromJson(messageData.toUtf8(), &error);
    if (error.error) {
        qWarning() << "Failed to parse text message as JSON object:" << messageData
                   << "Error is:" << error.errorString();
        return;
    } else if (!message.isObject()) {
        qWarning() << "Received JSON message that is not an object: " << messageData;
        return;
    }
    emit messageReceived(message.object(), this);
}