Hi,

I would like to have a ItemAdding so I can do some operations on it before it is added to the items collection is there a way to do this?
At this point I am using ItemAdded, what I want to do is generate a unique identifier and to do that I want to make some enforcements because the item gets added before I can do this check I have to filter it first it would be nice if I got a pre addition event to handle this type of functionally.

Hugo

Yes that would be OK, it is more like adding the final construction step depending on what is already on the items. but a validation event would be good, it you don't need the cancellation simply you don't set it. I am emulating the event by ignoring the node that got inserted.

eg.

void OnItemAdded(object sender, ItemEventArgs e)
{
if (e.Item is WidgetBase)
{
var widget = (WidgetBase)e.Item;
var widgets = Nodes.Cast<WidgetBase>()
.Where(w => w != widget);

if (widget.Id < 0)
widget.Id = widgets.FirstOrDefault() == null ? 0 : widgets.Max(s => s.Id) + 1;
}
}