ListView model update

[gogoer]

hello
i have ListView that displays list of files in folder.

                    ListView{
                        model: fileChecker.getFilesCount(folderID);
                        delegate: Item{
                                Button{
                                    anchors.fill: parent
                                    text: fileChecker.getFileName(index)
                                }
                         }
                   }

fileChecker class checks files in folder and returns their names.

when window creates, it have list of files, everething is ok. but i need to update list if files appears or disappears in the folder. how can i update ListView?

[dheerendra]

List view have property called model. Have you seen the ListModel methods ? like append, insert, delete ?

[J.Hilk]

Hi @gogoer ,
since fileChecker is a (c++?) class and you fetch your model via a function call, the model is only loaded once, during creation and no further updated.

You have 2 options.

• make it a proper Q_Property than your list view will update automatically
• create a signal in your class that is emitted once the model changes and manually react to that signal in qml to reset the model

//for example
Connections{
    target: fileChecker
    onFilesCountChanged: myListView.model = fileChecker.getFilesCount(folderID)
}

[gogoer]

i tryed to create function:

function updateModel(){
   myListView.model = fileChecker.getFilesCount(folderID)
}

and call it by pressing button, but nothing changes. why?

[Pradeep P N]

Hi @gogoer

Can you try using QAbstractListModel Class from QAbstractItemModel and expose it to QML.
Where you can pass the class to Listview { model } and you get all the options from the C++ Class.
Example

Or
As per my understanding in your present code you have to expose the update signal to QML so the model can be updated based on the signal.

[J.Hilk]

@gogoer said in ListView model update:

updateModel

are you sure updateModel is called ?
are you sure fileChecker.getFilesCount actually returns a list with the new entries?

function updateModel(){
   console.log("Attempt to update model")
   var newModel = fileChecker.getFilesCount(folderID);
  console.log("new Model", newModel) 
   myListView.model = newModel
}