How given sample works for ReverseInit?

In the sample page there is reverseInit as below. as far as I know reverseInit is only called when we use poppagemodel with data. Should we do poppage everytime when back button is clicked? How can this be handled sofware backbutton?

    //This is called when a pushed Page returns to this Page
    public override void ReverseInit (object value)
    {
        var newContact = value as Quote;
        if (!Quotes.Contains (newContact)) {
            Quotes.Add (newContact);
        }
    }

[stevechadbourne]

I think it should always be called. I have been caught out by this twice now (shame on me!) and had to find this issue to realise why it was not being called.

[djunod]

Figured it out after looking at your source…

protected override async void ViewIsDisappearing(object sender, EventArgs e)
{
    base.ViewIsDisappearing(sender, e);
    if (PreviousPageModel != null)
    {
        var dict = new Dictionary<string, string>
        {
            ["Project"] = Settings.SelectedProjectName,
            ["App"] = Constants.AppAsphalt,
            ["Lot"] = Lot.AsphaltLotID,
            ["Action"] = "Add",
        };
        PreviousPageModel.ReverseInit(dict);
    }
}