Receiving signals with arguments in QML from C++

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Receiving signals with arguments in QML from C++

The example code below shows how you can receive signals with arguments in QML from C++. The important thing to notice in the example is that the signal's argument needs to be named identically in QML and in C++. So in this example it needs to be referred to as "text" both places, otherwise you will receive errors.

main.cpp

#include <QtGui>
#include <QtDeclarative>

class Person : public QObject
{
 Q_OBJECT
public:
 Q_INVOKABLE void triggerEvent(QString text) {
  emit somethingHappened(text);
 }
 Person() {
  startTimer(1000);
 }
 void timerEvent(QTimerEvent *e) {
  QString text = "The text";
  triggerEvent(text);
 }
signals:
 void somethingHappened(QString text);
};

#include "main.moc"

int main(int argc, char** argv)
{
 QApplication app(argc, argv);
 qmlRegisterType<Person>("People", 1, 0, "Person");
 QDeclarativeView view;
 view.setSource(QUrl::fromLocalFile("main.qml"));
 view.resize(200,100);
 view.show();
 return app.exec();
}

main.qml

import People 1.0
import QtQuick 1.0

Person {
 id: myPerson
 onSomethingHappened: {
  console.log(" something happened " +text);
 }
}