Ok.
Solution founded.
In Short than ever you need functions that can use BlueprintFunctionLibraries or even SpawnActorOfClass from Anythere use variable of UserWidgetClassChild.
Example of selectable polimorfism:
- Create child of UserWidgetClass call it something like SpecificFunctionCallerBase_ActionName (You than can create childs and override functions there).
- In your UObjectChild create variable of that type.
- Select one of created FunctionCallers in that variable.
- Now you can just construct (or create widget ) from that variable and call any function you need from anythere.
Enjoy. Vote.
By the way Epic i hope you will give us the ability to use FunctionLibraryFunctions from UObjectChildClass directly.
Edit.
You can even use WidgetClass( it looks basicly as ordinary object) as parent than construct object of that type and call function but i dont know is this save or unsave to use.