ItemSelector is hard to use with generic models

[Alberto Mardegan]

Hi!
  The default delegate of ItemSelector, OptionSelectorDelegate, expects the text to be displayed to be in the "modelData" context variable. However, this variable is normally only available for ListModel or QStringList models. It's not clear how one should use ItemSelector with another model (defined from C++, for instance) which defines other role names but not "modelData".

I tried replacing the delegate of ItemSelector with a custom delegate, but nothing was displayed. I guess some documentation needs to be added to explain how to replace the delegate.

I ended up with this solution, which seems to be working well:

===============
        ListItem.ItemSelector {
            anchors.left: parent.left
            anchors.right: parent.right
            text: "Account"
            model: root.model
            delegate: OptionSelectorDelegate {
                property string modelData: model.displayName
            }
        }
===============

However, I wonder if this will be supported in the future or if I run the risk of seeing my code break when a new version of the UI toolkit is released.
So, I'd recommend to add documentation on how to address this case; also, the OptionSelectorDelegate is currently not displayed in the documentation, but I think it should be.

[Zsombor Egri (zsombi)]

modelData is available also in Repeater, generally available when the model is a number, an array or contains objects with one single role.