QML + QList<QObject*> won't work with setContextProperty

Malachi

I'm attempting to do something akin to https://doc.qt.io/qt-6/qtquick-modelviewsdata-cppmodels.html . Specifically I want a QList of QObject-derived instances to render in a QML ListView.

If I follow the examples exactly, it works. However, if I attempt to acquire the model through a custom Session object set to context, I run into issues.

Specifically, the session code looks like:

class Session : public QObject
{
    Q_OBJECT

    typedef QVariant result_type;

    Q_PROPERTY(result_type items READ items NOTIFY itemsChanged)
...
};

Then effectively we do a:

ListView {
    model: session.items
}

and in main:

    Session session;

    context->setContextProperty("session", &session);

I've spent around 4 hours on it now. Everything yields a "Required property was not initialized" despite verifying there is content in session.items

I'm happy to expand the example or feel free to browse full proof of concept code here https://bitbucket.org/malachib/playground.qt/src/master/src/PGQT-43/

Malachi

I have observed that if the consuming QML uses modelData rather than properties, things work as expected.

i.e.

delegate: RowLayout {
    required property string name
    Text { Layout.fillWidth: true; text: parent.name }
}

exhibits the problem at hand, while

delegate: RowLayout {
    Text { Layout.fillWidth: true; text: modelData.name }
}

Works.

According to the documentation, we expect the property version to work as well: "The QObject* is available as the modelData property. As a convenience, the properties of the object are also made available directly in the delegate's context"

So, the problem is still unsolved.