Creating a UFUNCTION

UFUNCTION() are useful because they are C++ functions that can be called from both your C++ client code as well as Blueprints diagrams. Any C++ function can be marked as a UFUNCTION().

How to do it...

1. Construct a UClass with a member function that you'd like to expose to Blueprints. Decorate that member function with UFUNCTION( BlueprintCallable, Category=SomeCategory) to make it callable from Blueprints. For example, the following is the Warrior class again:

   // Warrior.h
   class WRYV_API AWarrior : public AActor
   {
     GENERATED_BODY()
     public:
     UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Properties)
     FString Name;
     UFUNCTION(BlueprintCallable, Category = Properties)
     FString ToString();
   };
   
   // Warrior.cpp
   FString UProfile::ToString()
   {
     return FString::Printf( "An instance of UProfile: %s", *Name );
   }

2. Create an instance of your Warrior class by dragging an instance on to your game world.
3. From Blueprints, call the ToString() function on that Warrior instance by clicking on your Warrior instance. Then, in a Blueprints diagram, type in ToString(). It should look like in the following screenshot:
   

Tip

In order to call a function on an instance, the instance must be selected in the World Outliner when you start to type into the autocomplete menu in the Blueprints diagram, as shown in the following screenshot:

How it works…

UFUNCTION() are really C++ functions, but with additional metadata that make them accessible to Blueprints.