[QML] Persistance of ListModel data

ODБOï

Hi,
I have a qml page that shows a ListView, the model is updated at run time.
That page is loaded with a Loader (List_page.qml) .

How to keep the modelData in memory when i change the loaders source ? I want to assign the same data when List_page.qml is reloaded again.

Page{
   Loader{
     source : showList  ? "List_page.qml" : "Base_page.qml"
   }
}

Is this possible with QML Settings type ? I tryed this with no success

    Settings {
        id:_stg
        property alias mod : fm
    }
    ListView{
        id:fList
        model:_stg.mod        
    }
   ListModel{
        id:fm
    }

ODБOï

I found this solution https://stackoverflow.com/questions/48730166/how-to-save-and-restore-the-content-of-a-listmodel by @dtech

when my ListView page is destroyed datastore holds the list data but when i reload the page data is not restaured, so it looks like i have a issue with the Settings type..

Can someone tell me what could be the issue here please ?

import Qt.labs.settings 1.0

 property string datastore: ""

  Component.onCompleted: {
    if (datastore) { // will not enter here when reload the page
      dataModel.clear()
      var datamodel = JSON.parse(datastore)
      for (var i = 0; i < datamodel.length; ++i) dataModel.append(datamodel[i])
    }
  }

  Component.onDestruction : {
    var datamodel = []
    for (var i = 0; i < dataModel.count; ++i) datamodel.push(dataModel.get(i))
    datastore = JSON.stringify(datamodel)
    console.log(datamodel) 
  }

  Settings {
    property alias datastore: main.datastore
  }

Qt 5.11.0
Mingw32

Diracsbracket

@LeLev
Either you move the declaration of the ListModel to a persistent part of your app,
or you can save the data in the Settings, but not directly.

You will need to serialize the data as a long string... to save it and then deserialize it to get it back.
https://stackoverflow.com/questions/48730166/how-to-save-and-restore-the-content-of-a-listmodel

ODБOï

Finally i just followed @Diracsbracket suggestion and moved the model to a persistent part of my application. Thx @Diracsbracket

Diracsbracket

@LeLev
I didn't see your post where you tried the same link that I mentioned. Since it didn't work for you, did you set all of:

app.setOrganizationName()
app.setOrganizationDomain() 
app.setApplicationName()

in your main.cpp? This seems to be needed for Settings to work, since you target Windows.

ODБOï

@Diracsbracket said in [QML] Percistance of ListModel data:

did you set all of:
app.setOrganizationName()
app.setOrganizationDomain()
app.setApplicationName()

No, I will re-try Settings tomorrow morning.
Thank you very much