Handling delayed dbus method

blacky_i

Hello everyone!

I am developing dbus api and encontered with this, How to handle delayed dbus call? I have daemon app which is handling dbus requests and share plugin qml extension which is sending dbus method call to daemon app.

I followed this tutorial to create delayed method. After that I request some data from internet. Here is code:

//Creating delayed message
QVariant DBusAdaptor::getChatList(const int offset, const QDBusMessage &message)
{
    m_delayedList.append(RequestData());
    message.setDelayedReply(true);
    m_delayedList.last().reply = message.createReply();
    QDBusConnection::sessionBus().send(m_delayedList.last().reply);
    tdlibJson->getChats(0,
                        std::numeric_limits<std::int64_t>::max(),
                        5,
                        c_extraName);

    return QVariant();
}
//Sending delayed message with data
void DBusAdaptor::sendChatList()
{
    QDBusMessage reply = m_delayedList.last().reply;
    qDebug() << m_chats[0];
    reply << m_chats[0] << m_chats[1];
    QDBusConnection::sessionBus().send(reply);
    m_delayedList.removeLast();
    m_chatIds.clear();
    m_chats.clear();
}

//Filling list with data which will be send over dbus.
void DBusAdaptor::addChatItem(const QJsonObject &chatObject)
{
    if (chatObject.keys().contains("@extra"))
        if (chatObject["@extra"].toString() == c_extraName)
            m_chats.append(chatObject.toVariantMap());
    qDebug() << m_chats.size() << m_chatIds.size();
    if (m_chats.size() == m_chatIds.size())
        emit sendData();
}

In etension plugin I use this code:

    QDBusPendingCall async = remoteAppIface->asyncCall(c_dbusMethod, 0);
    dbusWatcher = new QDBusPendingCallWatcher(async, this);
    connect(dbusWatcher, &QDBusPendingCallWatcher::finished,
    [this](QDBusPendingCallWatcher * call) {
        QDBusPendingReply<QString, QByteArray> reply = *call;
        if (reply.isError())
            qDebug() << reply.error();
        else
            qDebug() << reply.argumentAt<0>();
        call->deleteLater();
    });

And I can't get data from method, all I get is emptyness with error message:

QDBusError("org.freedesktop.DBus.Error.InvalidSignature","Unexpected reply signature: got \"\", expected \"say\"")

I assume that handling delayed methods are different, but can't find any examples. Is there on internet any examples of this? Or There is an error in code?

Thanks in advance

blacky_i

I've solved it.

To handle long I did not have to send immediately reply (even though tutorial said that we have to). And delayed reply will be send.

Also in extension, QDBusPendingReply<QString, QByteArray> reply = *call; setting expecting signature to \"say\" and not looking to xml interface.