public void ReplaceItems_CallsHandleChangeWithCollectionPopulatedArgs()
{
var oldItems = new[] { CreateItem(), CreateItem() };
var newItems = new[] { CreateItem() };
Collection.Add(oldItems[0]);
Collection.Add(oldItems[1]);
ResetStub();
IVMCollection <IViewModel> c = Collection;
c.ReplaceItems(newItems, null);
AssertChangeArgs(
CollectionChangedArgs <IViewModel> .CollectionPopulated(Collection, oldItems)
);
}
/// <inheritdoc />
void IVMCollection <TItemVM> .ReplaceItems(IEnumerable <TItemVM> newItems, IChangeReason reason)
{
TItemVM[] oldItems = this.ToArray();
try {
IsPopulating = true;
Clear();
newItems.ForEach(Add);
// We have to call the behaviors BEFORE we raise the ListChanged event. The
// behavior chain does essential initialization (e.g. sets the descriptor).
// If we raise the ListChanged before, the UI may try to access the VMs before
// they are properly initialized.
CallBehaviors(CollectionChangedArgs <TItemVM> .CollectionPopulated(this, oldItems, reason));
} finally {
IsPopulating = false;
}
}
protected void HandleCollectionPopulated(TItemVM[] previousItems)
{
var args = CollectionChangedArgs <TItemVM> .CollectionPopulated(Collection, previousItems);
Behavior.HandleChange(Context, args);
}