[Interest] Best model type for shared data between C++ and QML, as well as insertion and removal on both sides.

[Nuno Santos]

Hi,

I need to implement a model class that allows me to have the data in C++ but exposed to QML.

The data will need to be exposed to QML and it will be necessary to write from QML to that model as well. 

The C++ side will be in charge of the data persistence.

I started with QQmlListProperty and it works for having data exposed from C++ to QML. The problem is that I also need to dynamically instantiate data on the QML side and write to the list. That doesn’t seem to be possible, or, if it is, I don’t know how to get there. So far I have only been able to write to the list, writing the items on the property it self. See example below.

What I am trying to do with QQmlListProperty is possible or should I adopt another model type such as QAbstractListModel?

Thanks

Nuno

Example:

// works
PatchSetManager {
    id: patchManager

    presets: [
        PatchSet {
            name: "Preset 1"
            patches: [
                Patch {
                    name: "Patch 1"
                },
                Patch {
                    name: "Patch 2"
                }
            ]
        }
    ]
}

// doesn’t work

var patchSet = Qt.createQmlObject('import Imaginando 1.0; PatchSet {}', patchManager);

if (patchSet)
{
    console.log("object created successfully");
}

patchSet.name = "test"

var patch = Qt.createQmlObject('import Imaginando 1.0; Patch {}', patchSet);

if (patch)
{
    patchSet.patches.append(patch)
    console.log(patchSet.patches + " length: " + patchSet.patches.length)
}