Is there a xamly way to populate StaticResource at runtime?

Question

I would actually prefer using a DynamicResource in this context, but it's impossible:

<Page.Resources>
  <CollectionViewSource
    x:Key="CategoriesCollection"
    Source="{Binding Context.CatsList, Source={x:Static Application.Current}}"/>


<DataGridComboBoxColumn
  Header="Category"
  ItemsSource="{Binding Source={StaticResource CategoriesCollection}}" 
  DisplayMemberPath="Title" />

I want to make that the CollectionViewSource should only be initialized on demand (i.e. when the first DataGridComboBoxColumn is created), is there a xamly way to do it?