How to modify the data in the model and update the view when new data is received from external?

[VRonin]

@VInay123 said in How to modify the data in the model and update the view when new data is received from external?:

For infor: I have hosted the project in Github: https://github.com/vinayrajputh/qtmodelview

Would have been nice if it compiled. Can you upload the ui and json file too?

[A Former User]

@VRonin : Done.

[VRonin]

I'm concentrating on the model only at the moment but it works perfectly for me.
The only thing that I would flag is that the json that you provided has all "ReadOnly": true so it won't allow changes unless you change that to false.

Could you try this fork and tell me what is that you expect to happen that is not happening?

[A Former User]

@VRonin: Now there is a function with following signature

void ScenarioPropertiesModel::onRefreshRoadInfo(const NewData& roadInfo) {}

Now i would ask you to set the model data (properties) to the new values present in roadInfo variable(or to a random number) in the above function and display it in the view.

My usecase is that, i will have a street and when user clicks on the street onRefreshRoadInfo will be called with the values which are actually coordinates and these i want to show.

[VRonin]

So you are confirming that, so far, the fork above is behaving correctly?

[A Former User]

@VRonin : Yes, it works correctly. :)

[VRonin]

Could you check the same fork now and see if onRefreshRoadInfo does what you expect?

[A Former User]

@VRonin : Hi Ronin, i checked your fork and it is working exactly as i need. So i tried to copy the code in my implementation and sadly it is not working, i even commented out the delegates. Could you please implement the ur logic in my code and see if you can make it work? I mean use the ui and view class. May be something is buggy in my view class? But there is nothing much in the view class too.

------Update--------
I tried to use your main function with my implementation as below so that my view class is used. But turns out the implementation does not work.

    QApplication a(argc, argv);
    //ScenarioPropertiesModel model;
    //QTreeView w;
    //w.setModel(&model);
    //w.show();
    PropertyEditorView view;// model creation and setting done in class constructor
 //   QPushButton sendRefreshRoadInfoButton("Refresh //Road Info");
//    sendRefreshRoadInfoButton.show();
    //QObject::connect(&sendRefreshRoadInfoButton,&QPushB//utton::clicked,&model,&ScenarioPropertiesModel::onRe//freshRoadInfo); i use my own signal and slot
    return a.exec();~~

When i modified the main as below it is working.

    QApplication a(argc, argv);
    ScenarioPropertiesModel model;
    PropertyEditorView w;
    w.ui_->treeView->setModel(&model); // removed setting from PropertyEditorView constructor as we set here
    w.show();
    QPushButton sendRefreshRoadInfoButton("Refresh Road Info");
    sendRefreshRoadInfoButton.show();
    QObject::connect(&sendRefreshRoadInfoButton,&QPushButton::clicked,&model,&ScenarioPropertiesModel::onRefreshRoadInfo); 
    return a.exec();

Do you see any reason for this behavior.

[SGaist]

Because on your first version of the code you are not connecting to the model you have in your PropertyEditorView but the one you declared above. On a side note, that can't compile since you commented out your model declaration.

[A Former User]

This post is deleted!

[A Former User]

@SGaist @JonB @VRonin : So i took a deep breathe and tried to implement my code from scratch using @VRonin solution i.e. his latest fork https://github.com/VSRonin/qtmodelview.
Now my code is working :). This was the piece of line which helped me:

    const QModelIndex parentIdx = index(0, 0);
    const QModelIndex xValueIndex = index(0, 1, parentIdx);
    setData(xValueIndex, 2.55);

Additionally deep inside my code i had two pointers to my view which was also the cause for not showing the new values. The thread can be closed. I have a request @VRonin if he could take out the link to the code as it is a part of commercial project. Thank you everyone for your help, especially @VRonin.