Repository.vb

Public Class CarRepository
    Private _cars As New ChangeTracker(Of Car)()

    Public Function GetCars() As IEnumerable(Of Car)
        'TODO: JET/ADO code here, you would obviously do in a for/while loop
        Dim dbId1 As Integer = 1
        Dim make1 As String = "Ford"
        Dim model1 As String = "Focus"

        'TODO: create or update car objects
        Dim car1 As Car
        If Not _cars.IsTracking(dbId1) Then
            car1 = New Car()
        Else
            car1 = _cars.GetItem(dbId1)
        End If

        car1.Make = make1
        car1.Model = model1

        If Not _cars.IsTracking(dbId1) Then
            _cars.StartTracking(dbId1, car1)
        End If

        Return _cars.GetTrackedItems()
    End Function

    Public Sub SaveCars(ByVal cars As IEnumerable(Of Car))
        'TODO: JET/ADO code here to update the item
        For Each changedItem As Car In _cars.GetChangedItems().Intersect(cars)
            Console.WriteLine(changedItem.Make)
        Next

        For Each newItem As Car In cars.Except(_cars.GetTrackedItems())
            'TODO: JET/ADO code here to add the item to the DB and get its new ID
            Dim newId As Integer = 5
            _cars.StartTracking(newId, newItem)
        Next

        _cars.SetNewCheckpoint()
    End Sub
End Class