endRemoveRows() and QML ListView deleteLater() synchronization

Zaraka

Hello,
I've stumbled on curious problem. If I deleteLater() object after caling endRemoveRows(). ListView delegates will not get destroyed in time and every binding to the deleted item will results in a lot of TypeError: Cannot read property 'foo' of null

Here's an example:
Let's preted that I have defined C++ Item

class MyItem : public QObject {
Q_OBJECT
Q_PROPERTY(QString foo READ foo WRITE setFoo NOTIFY fooChanged)
...
}

And I put these items into a QAbstractListModel

class MyModel : public QAbstractListModel {
    Q_OBJECT
public:
QHash<int, QByteArray> Model::roleNames() const {
    QHash<int, QByteArray> roles;
    roles[Qt::UserRole] = "object";
    return roles;
}
...
}

where data() with ObjectRole returns *Item
and I remove these Items like this

MyModel::removeItem(MyÏtem* item) {
    if (item && m_items.contains(item)) {
        int index = m_items.indexOf(item);
        beginRemoveRows(QModelIndex(), index, index);
        m_items.removeAt(index);
        endRemoveRows();
        item->deleteLater();
    }

Finally my QML for this model can be simple as this

ListView {
    delegate: Text {
        property MyItem myItem: model.object
        text: myItem.foo
    }
}

After removing item from model, Qt will fire that TypeError. but item will be destroyed both from C++ and from QML. But if I stall deleteLater like this QTimer::singleShot(10, [=]{ item->deleteLater();}); then everything will works okay. Also I have to use this nesting because my Items are quite big and I connect their signals and pass their pointer to a lot of places. I also have to delete object, because the item holds a lot of memory that I need to be freed.
It's obvious the C++ deletes object much faster than QML destroys ListView delegate. The question is, how can my C++ Model know when it is safe to deleteLater()?

SO_CubicF

Had the same problem.

Fixed it by not binding the object referenced by the role to a property and using the property but using the role name directly to acces the model item.

Instead of

property MyItem myItem: model.object
text: myItem.foo

try

text: model.object.foo