At the moment, bindings for dynamically created objects are evaluated immediately. This produces binding errors ("cannot assign [undefined] to X", etc.) if the created object has properties with bindings, as the property values have not yet been assigned.

A possible solution is to provide a two-step method for object creation. That is, in addition to Component::createObject(), have e.g. allocateObject() and finalizeObject() (which basically call beginCreate() and completeCreate() in QDeclarativeComponent) so you can do:

    component = Qt.createComponent("Sprite.qml");
    sprite = component.allocateObject(appWindow);

    if (sprite != null) {
        sprite.x = 100;
        sprite.y = 100;
        sprite.specialProperty = someObject
        component.finalizeObject()
    }

This way the bindings are not evaluated until finalizeObject() is called, thus avoiding the errors.