"Enum class"/Q_ENUM use in QML? Cannot read property of undefined

[sedi]

Hi, I use a number of enums in my project, which I keep in a single "Enums" class, each of them defined by the c+11 way of "enum class" and the new Q_ENUM macro (instead of Q_ENUMS, as proposed here).

I don't get them to work in QML, though - and all I can find about this topic (there are actually plenty of solutions!) is using the older concepts.

Below you find a minimized example project. On click, qml shall send Enums.DayOfWeek.MONDAY to a slot.
The result is:

qrc:/main.qml:17: TypeError: Cannot read property 'MONDAY' of undefined

where I'd expext qDebug output from the slot (environment: Qt 5.5, QtCreator 3.6, Win7x64).

Any ideas about how I could do it better / make it work?

Several Enums in enums.h

#ifndef ENUMS_H
#define ENUMS_H
#include <QObject>
 
class Enums
{
    Q_GADGET
 
public:
    enum class DayOfWeek {
        SUNDAY=0,
        MONDAY=1,
        TUESDAY=2,
        WEDNESDAY=3,
        THURSDAY=4,
        FRIDAY=5,
        SATURDAY=6,
        UNDEFINED=-1
    };
    Q_ENUM(DayOfWeek)
 
    enum class NameOrder {
        FIRST_FAMILY=0,
        FAMILY_FIRST=1
    };
    Q_ENUM(NameOrder)
 
};
 
#endif // ENUMS_H

#ifndef ENUMS_H
#define ENUMS_H
#include <QObject>

class Enums
{
    Q_GADGET

public:
    enum class DayOfWeek {
        SUNDAY=0,
        MONDAY=1,
        TUESDAY=2,
        WEDNESDAY=3,
        THURSDAY=4,
        FRIDAY=5,
        SATURDAY=6,
        UNDEFINED=-1
    };
    Q_ENUM(DayOfWeek)

    enum class NameOrder {
        FIRST_FAMILY=0,
        FAMILY_FIRST=1
    };
    Q_ENUM(NameOrder)

};

#endif // ENUMS_H

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An object with a slot that takes such an enum: someobject.h

#ifndef SOMEOBJECT_H
#define SOMEOBJECT_H
#include <QObject>
#include <QDebug>
#include "enums.h"
 
class SomeObject : public QObject
{
    Q_OBJECT
public:
    explicit SomeObject(QObject *parent = 0): QObject(parent) {}
public slots:
    void outputDay(Enums::DayOfWeek day) { qDebug()<<day; }
};
 
#endif // SOMEOBJECT_H

#ifndef SOMEOBJECT_H
#define SOMEOBJECT_H
#include <QObject>
#include <QDebug>
#include "enums.h"

class SomeObject : public QObject
{
    Q_OBJECT
public:
    explicit SomeObject(QObject *parent = 0): QObject(parent) {}
public slots:
    void outputDay(Enums::DayOfWeek day) { qDebug()<<day; }
};

#endif // SOMEOBJECT_H

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This is being registered in main.cpp

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QQmlEngine>
#include <QtQml>
#include "enums.h"
#include "someobject.h"
 
int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);
    QQmlApplicationEngine engine;
    qmlRegisterUncreatableType<Enums>("url.Enums", 1, 0, "Enums", "You cannot create an instance of the Enums.");
    qmlRegisterType<SomeObject>("url.SomeObject",1,0,"SomeObject");
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
    return app.exec();
}

#include <QGuiApplication>
#include <QQmlApplicationEngine>
#include <QQmlEngine>
#include <QtQml>
#include "enums.h"
#include "someobject.h"

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);
    QQmlApplicationEngine engine;
    qmlRegisterUncreatableType<Enums>("url.Enums", 1, 0, "Enums", "You cannot create an instance of the Enums.");
    qmlRegisterType<SomeObject>("url.SomeObject",1,0,"SomeObject");
    engine.load(QUrl(QStringLiteral("qrc:/main.qml")));
    return app.exec();
}

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And I try to use it in main.qml

import QtQuick 2.5
import QtQuick.Window 2.2
import url.SomeObject 1.0
import url.Enums 1.0
 
 
Window {
    visible: true
 
    SomeObject {
        id: myObject
    }
 
    MouseArea {
        anchors.fill: parent
        onClicked: {
            myObject.outputDay(Enums.DayOfWeek.MONDAY)
        }
    }
}

import QtQuick 2.5
import QtQuick.Window 2.2
import url.SomeObject 1.0
import url.Enums 1.0


Window {
    visible: true

    SomeObject {
        id: myObject
    }

    MouseArea {
        anchors.fill: parent
        onClicked: {
            myObject.outputDay(Enums.DayOfWeek.MONDAY)
        }
    }
}

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