How could you pass a nested container as an argument to an exposed DBus routine?

[digital_aspirin]

Hi everyone,
I would like to pass a QVariantList as an argument to a remotely called procedure using DBus. One of the items stored in the container is a QVariantMap which when I attempt to convert it from QVariant to QVariantMap the conversion fails. For instance:

void Ping::sendPing()
{
	QVariantMap mPingMap;
	mPingMap.insert("key1", "map: Ping says hello");
	mPingMap.insert("key2", 456);
 
	QVariantList lPingData;
 
	lPingData << "list: Ping says hello" << 123 << mPingMap;
 
	interfaceCallToPong->test(lPingData);
}

void Ping::sendPing()
{
	QVariantMap mPingMap;
	mPingMap.insert("key1", "map: Ping says hello");
	mPingMap.insert("key2", 456);
		
	QVariantList lPingData;
		
	lPingData << "list: Ping says hello" << 123 << mPingMap;
		
	interfaceCallToPong->test(lPingData);
}

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// The remote method:

void Pong::test( QvariantList lRemoteData )
{
	qDebug() << lRemoteData.at(0).toString();
	qDebug() << lRemoreData.at(1).toInt();
 
 
	QVariant qvMap = lRemoteData.at(3); // Get the variant that contains the QVariantMap
 
        qvMap.canConvert< QVariantMap > (); // returns false. Why?
 
        // As a result I got no valid data for the following.
        QVariantMap mRemoteMap = lRemoteData.at(3).toMap();
 
	qDebug() << mRemoteMap.value("key1").toString ();
	qDebug() << mRemoteMat.value("key2").toInt();
}

void Pong::test( QvariantList lRemoteData )
{
	qDebug() << lRemoteData.at(0).toString();
	qDebug() << lRemoreData.at(1).toInt();

	
	QVariant qvMap = lRemoteData.at(3); // Get the variant that contains the QVariantMap

        qvMap.canConvert< QVariantMap > (); // returns false. Why?

        // As a result I got no valid data for the following.
        QVariantMap mRemoteMap = lRemoteData.at(3).toMap();
	
	qDebug() << mRemoteMap.value("key1").toString ();
	qDebug() << mRemoteMat.value("key2").toInt();
}

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the output is:
list: Ping says hello
123
0
0

Apparently I am doing something wrong, unless we cannot pass nested containers as an argument to a remotely called procedure using DBus. Could you please help me out?

[stampede]

lPingData << "list: Ping says hello" << 123 << mPingMap;
///
qDebug() << lRemoteData.at(0).toString();
	qDebug() << lRemoreData.at(1).toInt();
	QVariant qvMap = lRemoteData.at(3); // are you sure not at(2)  ?

lPingData << "list: Ping says hello" << 123 << mPingMap;
///
qDebug() << lRemoteData.at(0).toString();
	qDebug() << lRemoreData.at(1).toInt();
	QVariant qvMap = lRemoteData.at(3); // are you sure not at(2)  ?

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For me it looks like the map argument is at index number 2, not 3

[digital_aspirin]

Yes you are right, it's a typo though. I have also tried to send a QVariantMap which one of its items is a QVariantList but the latter is empty at remote end as well. Although all data can be retrieved at source end before doing the remote procedure call.

[stampede]

I've just read the QtDbus docs:

All of the QtDBus types (primitives and user-defined alike) can be used to send and receive messages of all types over the bus.
Warning: You may not use any type that is not on the list above, including typedefs to the types listed. This also includes QList<QVariant> and QMap<QString,QVariant>.

Looks like you can't use those types. I have 0 experience with DBus programming, but maybe you can try with QDBusVariant.