NSToolbarItem migration

FROM : Todd Ditchendorf
DATE : Mon Feb 18 23:55:59 2008

I have a shipping application that uses an NSToolbar which autosaves. 
The toolbar's default set contains a toolbar item with a combobox and 
a toolbar item with a search field.

in the next version of my app, i want to replace these two toolbar 
items with a single toolbar item that contains a split view containing 
a combobox and search field. this toolbar item is still in the default 
set. the old toolbar items are to be removed altogether.

I have the new toolbaritem all setup in the new version. the problem 
is that when you run the new version for the first time, the toolbar 
contains neither the old toolbar items nor the new toolbar item. it's 
a very obvious problem, as the toolbar is almost empty. the user 
preferences are telling the toolbar to load the old separate  toolbar 
items which no longer exist.

at this point the user can run toolbar configuration and fix the 
issue, but that's not very nice to do to users. :0[

what's the best way to tell the toolbar that the new combined toolbar 
item should replace the old toolbar items that no longer exist?

todd ditchendorf