What's the accepted way to fill a QComboBox defined in QtQuick QML, from C++?

Question

I want to populate a QComboBox defined in QML from my C++ code. I have seen two possible ways to do this:

1. Define a list (as a QStringList for example) from the C++ code, and expose it as Q_ELEMENT. Then access that list from the C++, by saying model: backend.qlist assuming the list is defined in backend. Or
2. Find the QComboBox in the C++ code by using view.rootObject()->findChild(). Then use addItem() to populate the list.

What is best practice?

Answer 1

By far the first option!

QML stands for Qt Modeling Language, following the model-view architecture, in which the model (here C++) should not know anything about the view (QML).

Answer 2

The first option works very well. The implementation is easy. From C++ side create a method to return a list:

QVariantList getList()
{
    QVariantList list;
    
    list << "Op1";
    list << "Op2";
    list << "Op3";
           
    return list;
}

And then call the method by QML like this:

comboBoxReader.model = backend.getList()