I would suggest to use the objectrelation datatype for the "selection fields" . This does exactly what you want without needing to edit the edit template(s)
Just use a drop down list for the selection method and slect the node/folder where your types are listed. If there is a new type added, it will automatically appear in the drop down list when editing your "formation" class
I followed your advice Paul, but it seems that Object Relations is restricted to objects created before the class is created. The only choice in the type dropdown box is "only existing objects". Is there a way to set it to get even new content ?
I thought your type objects existed before objects of the formation class are created and that over time, some new types may be defined which will be available when editing existing formation objects or new formation objects.
But can't you create the folder already and fill it with a dummy type before ceating the formation class?
Well. I just can't understand what's happening. ^^
I tried a couple of hours ago and "objectrelation" didn't match what i expected. Then i tried with "objectrelationS" and it did, but it worked only with existing content (as i explained).
And I tried again with "objectrelation" and it works exactly like i'd like. Content added after the creation of the class is displayed in the dropdownbox... I swear i'm not drunk.