import QtQuick 2.0 Item { id: root property int initialValue: 0 property int behaviorCount: 0 Loader { id: loader objectName: "loader" active: false } Component.onCompleted: { loader.setSource("InitialPropertyValuesComponent.qml", {"canary": 3}); root.initialValue = loader.item.canary; // error - item should not yet exist. } }