If false, the user cannot expand a node that is handled by this editor: all editing is done via the editor. If true, the user can expand the node if it has subproperties: this allows the user to edit a record "one bit at a time" via the expansion or to edit it "as a whole" via this editor. This is also useful for displaying a read-only summary even if all modifications must be done via subproperties. The default is false.