How to set default value to "self"?

Development Programming & Scripting
1

126844-play.png

How can I get my function on the left to have the same “Target [self]” pin as the one on the right?

4 Likes
2

looking for this, myself.

From what I can tell:

for C++ defined functions: use UFUNCTION metadata ‘DefaultToSelf = <paramname>’
and it looks like you can set only one parameter per function to use this feature.

Sadly, I don’t see any path to using this in a blueprint-only implementation that doesn’t require engine changes. That being said, I don’t think it would be difficult. Something like, in UEdGraphSchema_K2::TrySetDefaultValue - compare with the meta keyword before doing the package lookup.

Alternately, exposing various other of the meta functionality to functions in the advanced interface would be nice.

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3

I am guessing here, but can’t you just put the right one into a variable and read it from there to the left one?

4

This fitted for my needs, may it helps you:

UFUNCTION(BlueprintCallable,
BlueprintPure, meta=(HidePin =
“WorldContextObject”, DefaultToSelf =
“WorldContextObject”)) static
AQuestManager* GetQuestManager(const
UObject* WorldContextObject);

4 Likes
5

yes. This is works. Here my own example.

UFUNCTION(BlueprintCallable, 
	meta = (HidePin = "WorldContextObject", DefaultToSelf = "WorldContextObject")
)
static void TestDefaultToSelf(UObject* WorldContextObject) {
	UE_LOG(LogTemp, Warning, TEXT("[WC object] name = %s"), *(WorldContextObject->GetName()))
	AActor* Actor = Cast<AActor>(WorldContextObject);
	if (Actor != nullptr) {
		UE_LOG(LogTemp, Warning, TEXT("[WC object] is AActor"))
	}
}

It will create bp node TestDefaultToSelf with one hidden pin.
I called it in BP_ThirdPersonCharacter this way:
image
And got this results:
image
Now WorldContextObject became refrence to bp actor that calls it.
Hope it helps someone.

1 Like
6

This is a bit old but for future reference:

For creating the node, the code below could be an example

UEdGraphPin* UK2Node_MyNode::TryCreateSelfPin()
{
	// Check if the blueprint qualifies for self
	UEdGraphPin* TargetPin = nullptr;
	auto bp = GetBlueprint()->GeneratedClass;
	auto bpgc = Cast<UBlueprintGeneratedClass>(bp.Get());
	auto defObj = bpgc->ClassDefaultObject;

	if (!defObj->IsA<UMyDesiredTypeForSelf>())
		return TargetPin;

	// Create a self pin
	TargetPin = CreatePin(EGPD_Input, UEdGraphSchema_K2::PC_Object, defObj->GetClass(), UEdGraphSchema_K2::PN_Self);
	TargetPin->PinFriendlyName = FText::FromName(FName("This is a self pin"));
	return TargetPin;
}

And to implement it in ExpandNode, you could utilize a K2Node_Self as IntermediateNode
connect its output pin.

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