How to do QObject::connect to QJSValue?-CodePudding

If Qml can do

MyComponent.connect(someJsFunction);

how can I do this on c ??? I need connect JSValue if it isCallable without workarounds. I want to know how it makes qml engine...

QObject::connect(QObject, signal, QJSValue, evaluateFunctionSlot);

CodePudding user response：

This will work. I got the solution from this SO post. That said, I don't know if it aligns with the Qt way of doing it. Their example of invoking a QML method uses QMetaObject::invokeMethod().

main.cpp

#include <QGuiApplication>
#include <QQuickItem>
#include <QQuickView>

class MyClass : public QObject
{
    Q_OBJECT
signals:
    void cppSignal(const QString &msg);
};

int main(int argc, char *argv[])
{
    QGuiApplication app(argc, argv);

    QQuickView view(QUrl(u"qrc:/75069400/main.qml"_qs));
    view.show();

    QObject *item = view.rootObject();
    MyClass myClass;
    QObject::connect(&myClass, SIGNAL(cppSignal(QString)),
                     item, SLOT(callFromCpp(QString)));

    emit myClass.cppSignal("this is a test");

    return app.exec();
}

#include "main.moc"

main.qml

import QtQuick

Rectangle {
    width: 320
    height: 240

    function callFromCpp(value : string) {
        console.log("QML" , value)
    }
}

CodePudding user response：

As result the best workaround:

qml

function connect(name, fn){
    myObject[name].connect(fn[name]);
}

QMetaObject::invokeMethod(MyObject, "connect", Q_ARG(QVariant, "anySlotName"), Q_ARG(QVariant, QVariant::fromValue(data)));