How to access C++ struct elements in QML

Praveen.Illa

Hi Team,

How can I access struct elements declared in Qt-C++ from QML.
Please find sample piece of code and pls let me know what I am doing wrong
Thank you

**Sample.h**
struct Details : public QObject
 {
          QString deviceName;
 }
class Sample : public QObject
{
      Q_PROPERTY(QList<Details *> list READ getList CONSTANT)
}

**Sample.cpp**
Sample::Sample()
{
    Details *dd1 = new Details ;
    dd1->setName("cc1");
    m_list.append(dd1);
}
QList<DeviceDetails *> Sample::getList()
{
    return m_list;
}

**main.cpp**
Sample sampleObj;
engine.rootContext()->setContextProperty("qmlSample", &sampleObj);

**main.qml**
    Column {
        anchors.centerIn: parent
        spacing: 10
        Repeater {
            model: qmlSample.list

            delegate: Row {
                spacing: 10

                    Text {
                        text: modelData.deviceName
                        font.pixelSize: 15
                    }
            }
        }
    }

sierdzio

@Praveen-Illa said in How to access C++ struct elements in QML:

modelData.deviceName

Just deviceName should be enough.

I hope you have used Q_OBJECT macro in all these QObject subclasses? And you have initialized parent class properly in constructor?

Are you getting any error from QML? If not, the problem might be much simpler: your Text, Row, Column elements have no dimensions (width and height).

Praveen.Illa

@sierdzio Hi, Thank you for your response.
Yes, I have define Q_OBJECT macro in all subclasses.
Even though, I am not able to access the struct elements.
Since, the above sample code provided is pseudo code, so I haven't mentioned all the details. sorry for that.
I came across this below link from stack overflow but I am not sure wether Qt supports or not support exposing struct elements to QML
https://stackoverflow.com/questions/7980900/qt-qml-c-qlist-of-structs-as-custom-listview-model#:~:text=QML cannot access "low-level,access these properties in QML.

Bob64

@Praveen-Illa in the code you provided in your initial message, you did not show the Q_OBJECT macros. If you are defining them, that means we are not seeing the same code that you are using so it is difficult to see what you might be doing wrong.

One thing I notice from your code is that you don't define deviceName as a Q_PROPERTY (see the answers in the StackOverflow link you mentioned). Is it the same in your real code?

Another thing to mention is that if you are just exposing a simple struct, it might be worth looking into using Q_GADGET instead.