C++ and QML integration, can't seem to access properties

Question

Ok. So I thought i had understood this completely, but obiously I have done something wrong and I can't for the life of me understand what. I've followed the tutorials to the letter (i checked) but can't get it to work, so here, let me ask a simple question.

I've created a QObject based class which has a simple QString variable that stores the name of the class (this is just for testing), it looks like this:

#include <QObject>

class CategoryPane : public QObject
{
    Q_OBJECT
    Q_PROPERTY(QString catName READ getCategoryName WRITE setCategoryName);

public:
    explicit CategoryPane(QObject *parent = 0);

    QString getCategoryName();
    void setCategoryName(QString);

signals:
    void nameChange();

private:
    QString categoryName;
};

This is registered with the following function: qmlRegisterType("ITI_UI", 1, 0, "CategoryPane");

And I'm trying to print out the name variable of my CategoryPane class in a QML-file that looks like this:

import QtQuick 1.0
import ITI_UI 1.0

Rectangle {
    width: 300
    height: 300

    CategoryPane {
        id: whatever
        catName: "ey"
        Text {
            text: whatever.catName
        }
    }
}

But I get the following error: qrc:/main.qml:11:3: Cannot assign to non-existent default property

Note: I get no error msg if I remove the Text {} field, but then again I can't print out my name string which is the whole point...

Thanks in advance for your time and patience!

fejd fejd · Accepted Answer · 2011-09-30T07:44:09

CategoryPane is being used like a visual item, but it derives from QObject. Have you tried inheriting from QDeclarativeItem instead?

If you just want to access the property and not use it as a visual item, you should be able to do like:

C++:

QDeclarativeView view;
CategoryPane pane;
view.rootContext()->setContextProperty("categoryPane", &pane);

QML:

import QtQuick 1.0

Rectangle {
    width: 300
    height: 300

    Text {
        text: categoryPane.catName
    }
}

C++ and QML integration, can't seem to access properties

1 Answers