[solved] Q_PROPERTY error

Miruvor

Hi,
I just a newbie in Qt. So, maybe solution for my problem is clear and simple, but I am not able to find it.
I have a separate header and cpp -files ( Codes below). Why compiler gives '...\message.cpp:11: error: 'textChanged' was not declared in this scope' error? As you can propably see, this is a one of the code examples found here. Just made little changes.

message.h
@
#ifndef MESSAGE_H
#define MESSAGE_H
#include <QGuiApplication>
#include <QQuickView>
#include <QString>

class Message: public QObject
{
Q_OBJECT
Q_PROPERTY(QString text READ text WRITE setText NOTIFY textChanged)

public:
Message();
void setText(const QString &);
QString text() const;

private:
QString m_text;
};

#endif // MESSAGE_H@

message.cpp
@#include "message.h"
using namespace std;
Message::Message()
{
m_text ="";
}
void Message::setText(const QString &Text)
{
if (Text != m_text) {
m_text = Text;
emit textChanged();
}
}
QString Message::text() const
{
return m_text;
}
@

SGaist

Hi and welcome to devnet,

You have not declared the textChanged signal (nor made setText a slot for that matter)

Your class should rather look like this:
@
class Message: public QObject
{
Q_OBJECT
Q_PROPERTY(QString text READ text WRITE setText NOTIFY textChanged)

public:
Message();
QString text() const;

signals:
void textChanged(const QString &text)

public slots:
void setText(const QString &text);

private:
QString m_text;
}
@

Miruvor

Thanks GSaist,
now code compiles and I'm able to continue my tutorial tour into the secrets of the Qt.

I took that code example from "here...":http://qt-project.org/doc/qt-5.0/qtqml/qtqml-cppintegration-exposecppattributes.html
@
class Message : public QObject
{
Q_OBJECT
Q_PROPERTY(QString author READ author WRITE setAuthor NOTIFY authorChanged)
public:
void setAuthor(const QString &a) {
if (a != m_author) {
m_author = a;
emit authorChanged();
}
}
QString author() const {
return m_author;
}
private:
QString m_author;
};@

So it seems that example were a little faulty.

Cheers!

SGaist

You're welcome !

Indeed, the documentation's example might need an update. You can check the "bug report system":https://bugreports.qt-project.org/issues/ to see whether there's already something for this. If not you could open a new report.

If it's all good for you now, can you update the thread title prepending [solved] so other forum users may know a solution has been found :)