How to expose dynamically amount of data to QML.

sandro4912

I have an app were I need to fetch random questions from a database and expose them to qml dynamically.

So I created a class to store each dataset:

class Question : public QObject
{
    Q_OBJECT
    Q_PROPERTY(int id READ id)
    Q_PROPERTY(QString askedQuestion READ askedQuestion)
public:
    Question(int id,
             QString askedQuestion);

    int getId() const;
    QString getAskedQuestion() const;

private:
    int mId;
    QString mAskedQuestion;
};

And fill them in annother class. In reality it is derrived from an SQLDatabaseModel:

class QuestionGenerator : public QObject
{
    Q_OBJECT
public:
    explicit QuestionGenerator(QObject *parent = nullptr);

    Q_INVOKABLE QVector<Question> getRandomQuestions(int count) const
    {
        // simplified in reality we fetch random questions from a database. 
        // the point is we need to add Questions to the vector
        // but this does not work since QObject based items cannot get copied
        QVector<Question> questions;
        questions.reserve(count);
        
        // add questions to vector
        
        return questions;
    }
};

I want to expose Question to QML to use the data from Question there so I need to derive it from QObject.

When I fetch the Questions randomly in QuestionGenerator it does not work because QVector does net the not supported copy constructor of QObject.

So how can I fix this?

Again what I want:

Fetch n Questions in C++ and expose them to QML so I can use the data to display.

ODБOï

@sandro4912
several options described here
https://doc.qt.io/qt-5/qtquick-modelviewsdata-cppmodels.html

sandro4912

I went for exposing a QQmlListProperty<Question> to QML. It works fine.