Sendig a model from C++ class to QML

alirezafour

Hi,
I have problem with loading a C++ model into the TableView in Qml.
the model:

//dataModel.h
#ifndef DATAMODEL_H
#define DATAMODEL_H

#include <QSqlQueryModel>

class dataModel : public QSqlQueryModel
{
    Q_OBJECT

public:
    explicit dataModel(QObject *parent = 0);
    void setQuery(const QString &query, const QSqlDatabase &db = QSqlDatabase());
    void setQuery(const QSqlQuery &query);
    QVariant data(const QModelIndex &index, int role) const;
    QHash<int, QByteArray> roleNames() const {	return m_roleNames;	}

private:
    void generateRoleNames();
    QHash<int, QByteArray> m_roleNames;
};


#endif // DATAMODEL_H

I have a Controller that create a object from this

//QmlController.h
#ifndef QMLCONTROLLER_H
#define QMLCONTROLLER_H

#include <QObject>
#include <QString>
#include <QQmlEngine>
#include <QJSEngine>
#include "database/database.h"
#include "model/datamodel.h"

class QmlController : public QObject
{
    Q_OBJECT
    Database db;
    dataModel m_model;
public:
    explicit QmlController(QObject *parent = 0);
    Q_INVOKABLE void insertData(QString date, QString title, QString inputMoney, QString outputMoney);
    Q_INVOKABLE void selectAll();
    Q_INVOKABLE dataModel &getModel();

signals:

public slots:

private:
    QString buildQuery(QString &date, QString &title, QString &inputMoney, QString &outputMoney);
};

static QObject *example_qobject_singletontype_provider(QQmlEngine *engine, QJSEngine *scriptEngine)
{
    Q_UNUSED(engine)
    Q_UNUSED(scriptEngine)

    QmlController *example = new QmlController();
    return example;
}
#endif // QMLCONTROLLER_H

and the definition of the getModel() is this:

//QmlController.cpp
dataModel &QmlController::getModel()
{
    return this->m_model;
}

main.cpp

//main.cpp
#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QQmlContext>
#include "qmlcontroller.h"

int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);

    QGuiApplication app(argc, argv);
    qmlRegisterSingletonType<QmlController>("test.myself", 1, 0, "ControllerCpp", example_qobject_singletontype_provider);
    qmlRegisterType<dataModel>("test.myself", 1, 0, "ModelMaster");
    QQmlApplicationEngine engine;
    engine.load(QUrl(QLatin1String("qrc:/main.qml")));

    return app.exec();
}

and I call the getModel() here:

//MyTable.qml
import QtQuick 2.0
import QtQuick.Controls 1.4
import test.myself 1.0

Item {
    TableView {
        id: tableViewId
        anchors.centerIn: parent
        width: 300
        height: 200
        model: ControllerCpp.getModel()
        TableViewColumn { ... }
    }

}

there is no error that I can understand where the problem is but I think I have problem with getModel()
because all other methods work just find and add data to database but this method doesn't work I guess.

Eddy

Hi alirezafour ,

There is a working example with the same goal as yours in this thread

alirezafour

Thnaks @Eddy
my problem solved by changing the m_model to a QPointer<dataModel> and change dataModel &QmlController::getModel() to dataModel *QmlController::getModel()

Eddy

Good deal !