How to set property into a sub context?



  • Hello,

    I try to pass an object (ListModel) into a sub-context of an component that I have created, but I have this error:
    QQmlContext: Cannot set property on internal context

    Here, my attempts:
    @
    QQmlComponent component(engine, QUrl::fromLocalFile("myScene.qml"));
    QObject object = component.beginCreate( engine->rootContext() );
    qobject_cast<QQuickItem
    >(object)->setParentItem(window2); //assign my scene to a qml window. window2 is a QQuickItem

    QQmlContext *context0 = engine->rootContext(); //works but conflict
    QQmlContext *context1 = engine->contextForObject( window2 ); //doesn't work
    QQmlContext *context2 = engine->contextForObject( object ); //doesn't work
    QObject object2 = object->findChild<QQuickItem>("Rect"); //Rect is the first child in myScene
    QQmlContext *context3 = engine->contextForObject( object2 ); //doesn't work
    QObject object3 = object->findChild<QQuickItem>("myRepeter"); //myRepeter is the final child which uses my property
    QQmlContext *context4 = engine->contextForObject( object3 ); //doesn't work

    context2->setContextProperty("myList", myModelList);
    component.completeCreate();

    @

    Why is it not possible to set a property elsewhere than the rootcontext?

    I can't use the rootcontext because I will create several scenes with several differents models.
    With the root context, there is a name conflit.

    I also tried to use:
    @
    object3->setProperty("myList", myModelList);
    @

    but i have a lot of compilation errors.

    Probably, I will try to use a table of models and set an index into my "myScene" to solve my problem.
    But I want to know why is it not possible to set a object to the context of an child item, or how to avoid conflicts of names in this situation?

    Thanks.



  • "Here, ":http://qt-project.org/doc/qt-5.1/qtqml/qqmlengine.html
    I read that:
    @
    QQmlContext * QQmlEngine::rootContext() const
    ...
    Additional data that should only be available to a subset of component instances should be added to sub-contexts parented to the root context.
    @
    So, it is possible to create data to a sub-context.
    How I have to do?
    A property isn't data?

    I solved my problem by using a ListModel main which contains several sub-ListModels and by assigning an ID to each scene and a invokable method wich return the corresponding model.
    But I want to know for the futur.

    Thanks.



  • Ok, I found:

    @
    QQmlContext *context1 = new QQmlContext(engine, qApp);
    context1->setContextProperty("myList", modelList_1 );
    QQmlComponent component1(engine, QUrl::fromLocalFile("myScene.qml"), this);
    QObject object1 = component1.beginCreate( context1 );
    qobject_cast<QQuickItem
    >(object1)->setParentItem( window1 );
    component1.completeCreate();

    QQmlContext *context2 = new QQmlContext(engine, qApp);
    context2->setContextProperty("myList", modeList_2 );
    QQmlComponent component2(engine, QUrl::fromLocalFile&#40;"myScene.qml"&#41;, this&#41;;
    QObject *object2 = component2.beginCreate( context2 );
    qobject_cast<QQuickItem*>(object2)->setParentItem( window2 );
    component2.completeCreate();
    
    
    QQmlContext *context3 = new QQmlContext(engine, qApp);
    context3->setContextProperty("myList", modelList_3 );
    QQmlComponent component3(engine, QUrl::fromLocalFile&#40;"myScene.qml"&#41;, this&#41;;
    QObject *object3 = component3.beginCreate( context3 );
    qobject_cast<QQuickItem*>(object3)->setParentItem( window3 );
    component3.completeCreate();
    

    @

    So, I don't have of name conflict (each scene uses "myList" model name, but shows differents data).

    But why it isn't possible to set property into internal context? There is an explication?


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