QML call to ContextObject function with Enum Parameter

Dong

Hi everyone !

I have problem with this simple situation.
I use setContextObject to implement M-V-VM pattern.
And in QML, I want to call to VM function with enum parameter
but I get

Error: Unknown method parameter type: AdsProvider::EnumAdsProvider

This is my ViewModel Class

class MainWindowViewModel : public DynamicObject
{
    Q_OBJECT
public:
    MainWindowViewModel(QObject *parent = 0);

    Q_INVOKABLE void showLoginDialog(AdsProvider::EnumAdsProvider engine);
};

This is the Enum declaration

class AdsProvider : public QObject
    {
        Q_OBJECT
    public:
        //static const QString GOOGLE;
        //static const QString BING;
        static QString Username;

        enum EnumAdsProvider
        {
            GOOGLE,
            BING,
            FACEBOOK
        };
        Q_ENUMS(EnumAdsProvider)

        static void registerType()
        {
            qmlRegisterType<AdsProvider>("SystemConstants", 1, 0, "AdsProvider");
        }
    };

I'm already register the custom Type & Enum like this

    AdsProvider::registerType();
    qmlRegisterType<DynamicObject>("core.dynamicobject", 1, 0, "DynamicObject");
    qmlRegisterType<MainWindowViewModel>("Presentation.ViewModel", 1, 0, "MainWindowViewModel");

Here is the QML code call to VM function

import Presentation.ViewModel 1.0
import SystemConstants 1.0

ApplicationWindow {
    id:root
    ...
    ToolButton{
        iconSource: "qrc:/login.png"
        onClicked:
        {
            showLoginDialog(AdsProvider.FACEBOOK);
        }
    }
    ...
}

If I change the the parameter type in VM's function to int, it worked !!!
But I want to know exactly Enum type instead of int for any Enum parameters.

Please Help !!! Thanks a lots !!!

t3685

@Dong
I usually put Q_ENUMS macro right afte Q_OBJECT. Maybe that helps?

EmilieG

I know this in an old topic, but I'm having the exact same issue, and can't find a solution. Anyone know how to fix that properly ?

KroMignon

@EmilieG said in QML call to ContextObject function with Enum Parameter:

Anyone know how to fix that properly ?

as @t3685 already write, you have to ensure the enumeration is registered with Q_ENUM() or Q_ENUMS()

==> take a look at https://doc.qt.io/qt-5/qtqml-cppintegration-data.html#enumeration-types for more details

ODБOï

@EmilieG hi
this one way to do it

class MyClass: public QObject
{
    Q_OBJECT
public :
  enum class CurrentState : qint32{
        STAND_BY,
        RUNNING,
        ERROR   
    };
    Q_ENUM(CurrentState)

    Q_INVOKABLE void testEnumArg(CurrentState s){
        qDebug() << s;
    }


};
Q_DECLARE_METATYPE(MyClass::CurrentState)

//in main.cpp for example 

qmlRegisterType<MyClass>("com.MyClass.test", 1, 0, "MyClass"); // make enum accessible in qml
// +  create an instance  of that class and use setContextProperty() to make it avalable in qml and call the invokable method

// in qml 
import com.MyClass.test 1.0 
...
classObject.testEnumArg(MyClass.STAND_BY)