How to implement WPF-like MVVM in Qt/C++/QML?

Question

I'm writing a proof of concept application, that is very simple. Basically it's composed of a UI where a list of "Note" type objects is displayed in a QML ListView.

I then have a few classes which is something along the lines:

#ifndef NOTE_H
#define NOTE_H

#include <string>

using namespace std;
class Note
{
public:
    Note(QObject* parent = 0)
        : QObject(parent)
    {

    }

    Note(const int id, const string& text)
        : _id(id), _text(text)
    {
    }

    int id()
    {
        return _id;
    }

    const string text()
    {
        return _text;
    }

    void setText(string newText)
    {
        _text = newText;
    }

private:
    int _id;
    string _text;
};

#endif // NOTE_H

Then a repository:

class NoteRepository : public Repository<Note>
{
public:
    NoteRepository();
    ~NoteRepository();

    virtual shared_ptr<Note> getOne(const int id);
    virtual const unique_ptr<vector<Note>> getAll();
    virtual void add(shared_ptr<Note> item);
private:
    map<int, shared_ptr<Note>> _cachedObjects;
};

Finally a ViewModel that exposes Note to QML

class MainViewModel : public QObject
{
    Q_OBJECT
    Q_PROPERTY(QQmlListProperty<Note> notes READ notes NOTIFY notesChanged)
    Q_PROPERTY(int count READ count() NOTIFY countChanged)
public:
    MainViewModel(QObject *newParent = 0);
    int count();
    QQmlListProperty<Note> notes();
signals:
    void notesChanged();
    void countChanged();
public slots:
private:
    std::shared_ptr<UnitOfWork> _unitOfWork;
    static void appendNote(QQmlListProperty<Note> *list, Note *note);
    QList<Note*> _notes;
};

PLEASE DON'T MIND ANY C++ MISTAKES HERE and mind they are incomplete, it's not the point at this moment as I'm constantly adapting this as I learn.

The point where I'm struggling is, how to expose a list-like object to QML? The requirement is this list must be dynamic, one should be able to add, delete and modify the text of a note. When the list is modified by C++, it should also notify the UI (signal).

I tried QQmlListProperty, but couldn't figure a way of exposing it to QML. Then I read on another SO post this type can't be modified by QML (??), and I stumbled upon QAbstractItemModel.

Anyhow, can anyone point me to the right direction?

Answer 1

The accepted answer is correct save for one detail. In MVVM you'd expose the ViewModel to QML, not the Model.