Display Data from C++ to QML

[Binary01]

Hi EveryOne,

I have a C++ class that does some operations
The method : getDataFromServer() exports some Data from server, it works well

for (int i = 0; i < projects.size(); ++i)
    {
        qDebug() << "result : " << projects[i];
    }

for (int i = 0; i < projects.size(); ++i)
    {
        qDebug() << "result : " << projects[i];
    }

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I want to display data in Listview QML

QML code

Rectangle
{
    Component.onCompleted: {
        ClassTest.getDataFromServer();
    }
 
    ClassTest{
        id: classTest
    }
 
    Item {
        width: 800
        height: 600
 
        ListView {
            id: listView
            anchors.left: parent.left
            anchors.top: parent.top
            anchors.bottom: parent.bottom
            width: 0.25 * parent.width
 
            focus: true
            model: myModel
            delegate: Item {
 
                width: parent.width
                height: 22
 
                Text {
                    anchors.centerIn: parent
                    text: "data"
                }
 
                MouseArea {
                    anchors.fill: parent
                    onClicked: {
                        console.log(model.index)
                    }
 
                }
            }
        }
    }

Rectangle
{
    Component.onCompleted: {
        ClassTest.getDataFromServer();
    }

    ClassTest{
        id: classTest
    }

    Item {
        width: 800
        height: 600

        ListView {
            id: listView
            anchors.left: parent.left
            anchors.top: parent.top
            anchors.bottom: parent.bottom
            width: 0.25 * parent.width

            focus: true
            model: myModel
            delegate: Item {

                width: parent.width
                height: 22

                Text {
                    anchors.centerIn: parent
                    text: "data"
                }

                MouseArea {
                    anchors.fill: parent
                    onClicked: {
                        console.log(model.index)
                    }

                }
            }
        }
    }

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getDataFromServer() code

...
   // getData OK
    for (int i = 0; i < projects.size(); ++i)
    {
        qDebug() << "result : " << projects[i];
    }
    QQuickView *view= new QQuickView;
    QQmlContext *c = view->engine()->rootContext();
    c->setContextProperty("myModel",  QVariant::fromValue(projects));

...
   // getData OK
    for (int i = 0; i < projects.size(); ++i)
    {
        qDebug() << "result : " << projects[i];
    }
    QQuickView *view= new QQuickView;
    QQmlContext *c = view->engine()->rootContext();
    c->setContextProperty("myModel",  QVariant::fromValue(projects));

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Any help plz

Cheers,

[anda_skoa]

Your getDataFromServer() creates a new view?

Cheers,
_

[Binary01]

The object is to display Data in QML

I created a new QML file code above , I would like to communicate C++ class and This QML file, so I tried to use :

QQuickView *view= new QQuickView;
    QQmlContext *c = view->engine()->rootContext();
    c->setContextProperty("myModel",  QVariant::fromValue(projects));

QQuickView *view= new QQuickView;
    QQmlContext *c = view->engine()->rootContext();
    c->setContextProperty("myModel",  QVariant::fromValue(projects));

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Is this an other way simple to do that ??

[anda_skoa]

The object is to display Data in QML

If you create another view, it is another view.
In C++ two instance of a class are two different objects, with their owns state/data.

Is this an other way simple to do that ??

Either a property on an object exposed to QML or a model exposed to QML.
What's the element type of "projects"?

Cheers,
_

[Binary01]

projects is a QStringList : QStringList projects

Yeah I used a model exposed to QML : myModel

I tried to use the example : http://doc.qt.io/qt-5/qtquick-modelv...cppmodels.html

Cheers,

[anda_skoa]

projects is a QStringList : QStringList projects

Ah, good, easy

Yeah I used a model exposed to QML : myModel

Currently you are not, your non-working code exports the QStringList as a context property.

I assume "ClassTest" is a custom C++ type that you have registered with the QML type system?

Just add a QStringList property to it and bind the ListView's model to that instead of myModel.

ClassTest {
    id: classTest
}
 
ListView {
    model: classTest.projects // assuming you give your property the name "projects"
}

ClassTest {
    id: classTest
}

ListView {
    model: classTest.projects // assuming you give your property the name "projects"
}

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Cheers,
_

[Binary01]

Yeah, "ClassTest" is a custom C++ type registered with the QML type system

Is it necessary to add a new property ??

In ClassTest, I added projects

Q_PROPERTY(QStringList projects READ projects)

Q_PROPERTY(QStringList projects READ projects)

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In QML

ListView {
    model: classTest.projects 
}

ListView {
    model: classTest.projects 
}

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In C++

// getDataFromServer() == Get data From server
    for (int i = 0; i < projects.size(); ++i)
    {
        qDebug() << "result : " << projects[i];
    }
 
    QQuickView *view= new QQuickView;
    QQmlContext *ctxt = view->engine()->rootContext();
    ctxt->setContextProperty("myModel",  QVariant::fromValue(projects));

// getDataFromServer() == Get data From server
    for (int i = 0; i < projects.size(); ++i)
    {
        qDebug() << "result : " << projects[i];
    }

    QQuickView *view= new QQuickView;
    QQmlContext *ctxt = view->engine()->rootContext();
    ctxt->setContextProperty("myModel",  QVariant::fromValue(projects));

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Still not work
C++ code should remain as such it is ??

Cheers,

[anda_skoa]

Yeah, "ClassTest" is a custom C++ type registered with the QML type system

Great, that makes everything easy.

Is it necessary to add a new property ??

That's the easiest way.
Do you need a more complicated approach?

In ClassTest, I added projects

Q_PROPERTY(QStringList projects READ projects)

Q_PROPERTY(QStringList projects READ projects)

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Needs a NOTIFY signal, since the value is changing after object creation.

In QML

ListView {
    model: classTest.projects 
}

ListView {
    model: classTest.projects 
}

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Exactly.

In C++

// getDataFromServer() == Get data From server
    for (int i = 0; i < projects.size(); ++i)
    {
        qDebug() << "result : " << projects[i];
    }
 
    QQuickView *view= new QQuickView;
    QQmlContext *ctxt = view->engine()->rootContext();
    ctxt->setContextProperty("myModel",  QVariant::fromValue(projects));

// getDataFromServer() == Get data From server
    for (int i = 0; i < projects.size(); ++i)
    {
        qDebug() << "result : " << projects[i];
    }

    QQuickView *view= new QQuickView;
    QQmlContext *ctxt = view->engine()->rootContext();
    ctxt->setContextProperty("myModel",  QVariant::fromValue(projects));

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We've already determined that this is very wrong, no?

Once the value of the property has changed, you emit the change notifcation signal.

Cheers,
_