Lots of work on FormatMessage and FormatErrorMessage. These can now print enums.

Source/Integration/BlueprintErrors.cpp

@@ -83,6 +83,15 @@ FFormatArgumentData UlxFormatDataLibrary::FormatArgumentDataBool(bool Value, con
 	return Result;
 }
 
+FFormatArgumentData UlxFormatDataLibrary::FormatArgumentDataByte(uint8 Value, const FString &Name)
+{
+	FFormatArgumentData Result;
+	Result.ArgumentValueType = EFormatArgumentType::Int;
+	Result.ArgumentName = Name;
+	Result.ArgumentValueInt = Value;
+	return Result;
+}
+
 FFormatArgumentData UlxFormatDataLibrary::FormatArgumentDataInt(int Value, const FString &Name)
 {
 	FFormatArgumentData Result;
@@ -200,7 +209,7 @@ FFormatArgumentData UlxFormatDataLibrary::FormatArgumentDataTransform(const FTra
 	return Result;
 }
 
-FFormatArgumentData UlxFormatDataLibrary::FormatArgumentDataBlank(const FString &Name)
+FFormatArgumentData UlxBlueprintErrorLibrary::FormatArgumentDataBlank(const FString &Name)
 {
 	FFormatArgumentData Result;
 	Result.ArgumentValueType = EFormatArgumentType::Text;
@@ -209,6 +218,25 @@ FFormatArgumentData UlxFormatDataLibrary::FormatArgumentDataBlank(const FString
 	return Result;
 }
 
+FFormatArgumentData UlxBlueprintErrorLibrary::FormatArgumentDataEnum(uint8 Value, const FString &Name, const UObject *PinSubCategoryObject)
+{
+	const UEnum *Enum = Cast<const UEnum>(PinSubCategoryObject);
+	FFormatArgumentData Result;
+	if (Enum == nullptr)
+	{
+		Result.ArgumentValueType = EFormatArgumentType::Int;
+		Result.ArgumentName = Name;
+		Result.ArgumentValueInt = Value;
+	}
+	else
+	{
+		Result.ArgumentValueType = EFormatArgumentType::Text;
+		Result.ArgumentName = Name;
+		Result.ArgumentValue = FText::Format(INVTEXT("<{0}>"), Enum->GetDisplayNameTextByValue(Value));
+	}
+	return Result;
+}
+
 FlxDebugBlueprintErrorsOutputDevice::FlxDebugBlueprintErrorsOutputDevice(const ElxLogVerbosity &SensitivityRef)
     : Sensitivity(SensitivityRef)
 {

Source/Integration/BlueprintErrors.h

@@ -144,6 +144,16 @@ public:
 	UFUNCTION(BlueprintCallable, meta=(WorldContext = "Context", BlueprintInternalUseOnly = "true"))
 	static void FormatErrorInternal(UObject *Context, ElxLogVerbosity Verbosity, ElxErrorDisplayDuration DisplayDuration, const FString &InPattern, TArray<FFormatArgumentData> InArgs);
 
+	// A formatting routine for pins that were never connected.
+	//
+	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
+	static FFormatArgumentData FormatArgumentDataBlank(const FString &Name);
+
+	// A specialized formatting routine for pins of enum types.
+	//
+	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
+	static FFormatArgumentData FormatArgumentDataEnum(uint8 Value, const FString &Name, const UObject *PinSubCategoryObject);
+
     // Convert an ElxLogVerbosity to an ELogVerbosity::Type
     //
     static ELogVerbosity::Type ConvertElxLogVerbosity(ElxLogVerbosity Verbosity);
@@ -162,6 +172,9 @@ public:
 	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
 	static FFormatArgumentData FormatArgumentDataBool(bool Value, const FString &Name);
 
+	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
+	static FFormatArgumentData FormatArgumentDataByte(uint8 Value, const FString &Name);
+
 	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
 	static FFormatArgumentData FormatArgumentDataInt(int Value, const FString &Name);
 
@@ -200,9 +213,6 @@ public:
 
 	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
 	static FFormatArgumentData FormatArgumentDataTransform(const FTransform &Value, const FString &Name);
-
-	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
-	static FFormatArgumentData FormatArgumentDataBlank(const FString &Name);
 };
 
 /* Debug Blueprint Errors output device. 

Source/Integration/FormatError.cpp

@@ -37,7 +37,7 @@
 #include "UObject/WeakObjectPtr.h"
 #include "UObject/WeakObjectPtrTemplates.h"
 
-#define LOCTEXT_NAMESPACE "FormatError"
+#define LOCTEXT_NAMESPACE "FormatMessage"
 
 // All argument pins will have Names that start with "A:"
 
@@ -71,26 +71,19 @@ static bool IsFormatPin(const UEdGraphPin *Pin) {
 	return (Pin->PinName == FormatPinName);
 }
 
-UK2Node_FormatError::UK2Node_FormatError(const FObjectInitializer& ObjectInitializer)
-	: Super(ObjectInitializer)
-{
-	NodeTooltip = LOCTEXT("NodeTooltip", 
-		"Output an error, warning, or informational message to the log file.\n"
-		"\n"
-		"  \u2022 Use {ArgName} to denote format arguments, giving each argument a different ArgName.\n"
-		"\n"
-		"It is often desirable to use this in conjunction with a separate utility that\n"
-		"pauses the execution of the blueprint whenever an error is logged."
-		);
+static const FName ResultPinName(TEXT("Result"));
+static bool IsResultPin(const UEdGraphPin *Pin) {
+	return (Pin->PinName == ResultPinName);
 }
 
-void UK2Node_FormatError::AllocateDefaultPins()
+
+void UK2Node_FormatMessage::AllocateDefaultPins()
 {
 	Super::AllocateDefaultPins();
 	CreateCorrectPins();
 }
 
-void UK2Node_FormatError::CreateCorrectPins()
+void UK2Node_FormatMessage::CreateCorrectPins()
 {
 	if (FindPin(UEdGraphSchema_K2::PN_Execute) == nullptr) {
 		CreatePin(EGPD_Input, UEdGraphSchema_K2::PC_Exec, UEdGraphSchema_K2::PN_Execute);
@@ -105,19 +98,34 @@ void UK2Node_FormatError::CreateCorrectPins()
 		P->DefaultValue = TEXT("Error Message");
 	}
 
-	if (FindPin(VerbosityPinName, EGPD_Input) == nullptr) {
-		UEdGraphPin *P = CreatePin(EGPD_Input, UEdGraphSchema_K2::PC_Byte, StaticEnum<ElxLogVerbosity>(), VerbosityPinName);
-		P->DefaultValue = TEXT("Error");
-		P->AutogeneratedDefaultValue = P->DefaultValue;
+	// If this is a FormatMessage node, create a pin to output the result as text.
+	//
+	if (!IsFormatErrorMessage())
+	{
+		if (FindPin(ResultPinName, EGPD_Output) == nullptr) {
+			CreatePin(EGPD_Output, UEdGraphSchema_K2::PC_Text, ResultPinName);
+		}
 	}
 
-	if (FindPin(DisplayDurationPinName, EGPD_Input) == nullptr) {
-		UEdGraphPin *P = CreatePin(EGPD_Input, UEdGraphSchema_K2::PC_Byte, StaticEnum<ElxErrorDisplayDuration>(), DisplayDurationPinName);
-		P->DefaultValue = TEXT("No_Show");
-		P->AutogeneratedDefaultValue = P->DefaultValue;
+	// If this is a FormatErrorMessage node, create pins that control the log verbosity
+	//
+	if (IsFormatErrorMessage())
+	{
+		if (FindPin(VerbosityPinName, EGPD_Input) == nullptr) {
+			UEdGraphPin *P = CreatePin(EGPD_Input, UEdGraphSchema_K2::PC_Byte, StaticEnum<ElxLogVerbosity>(), VerbosityPinName);
+			P->DefaultValue = TEXT("Error");
+			P->AutogeneratedDefaultValue = P->DefaultValue;
+		}
+
+		if (FindPin(DisplayDurationPinName, EGPD_Input) == nullptr) {
+			UEdGraphPin *P = CreatePin(EGPD_Input, UEdGraphSchema_K2::PC_Byte, StaticEnum<ElxErrorDisplayDuration>(), DisplayDurationPinName);
+			P->DefaultValue = TEXT("No_Show");
+			P->AutogeneratedDefaultValue = P->DefaultValue;
+		}
 	}
 
 	// Transfer all Existing Argument pins to the Old Pins Map.                                                                               
+	//
 	TMap<FString, UEdGraphPin *> OldPins;
 	for (auto It = Pins.CreateIterator(); It; ++It)
 	{
@@ -130,6 +138,7 @@ void UK2Node_FormatError::CreateCorrectPins()
 	}
 
 	// Create Argument pins in the correct order, reusing old pins where possible.                                                                    
+	//
 	for (const FString& Name : PinNames)
 	{
 		UEdGraphPin **OldPin = OldPins.Find(Name);
@@ -143,6 +152,7 @@ void UK2Node_FormatError::CreateCorrectPins()
 	}
 
 	// Delete any unused pins.                                                                                                                
+	//
 	for (auto &iter : OldPins)
 	{
 		iter.Value->Modify();
@@ -152,7 +162,7 @@ void UK2Node_FormatError::CreateCorrectPins()
 }
 
 
-void UK2Node_FormatError::SynchronizeArgumentPinType(UEdGraphPin* Pin)
+void UK2Node_FormatMessage::SynchronizeArgumentPinType(UEdGraphPin* Pin)
 {
 	if (IsArgumentPin(Pin))
 	{
@@ -196,12 +206,19 @@ void UK2Node_FormatError::SynchronizeArgumentPinType(UEdGraphPin* Pin)
 	}
 }
 
-FText UK2Node_FormatError::GetNodeTitle(ENodeTitleType::Type TitleType) const
+FText UK2Node_FormatMessage::GetNodeTitle(ENodeTitleType::Type TitleType) const
 {
-	return LOCTEXT("FormatError_Title", "Format Error Message");
+	if (IsFormatErrorMessage())
+	{
+		return LOCTEXT("FormatErrorMessage_Title", "Format Error Message");
+	}
+	else
+	{
+		return LOCTEXT("FormatMessage_Title", "Format Message");
+	}
 }
 
-FText UK2Node_FormatError::GetPinDisplayName(const UEdGraphPin* Pin) const
+FText UK2Node_FormatMessage::GetPinDisplayName(const UEdGraphPin* Pin) const
 {
 	// The exec pins don't need labels.
 	if (Pin->PinType.PinCategory == UEdGraphSchema_K2::PC_Exec)
@@ -227,10 +244,10 @@ FText UK2Node_FormatError::GetPinDisplayName(const UEdGraphPin* Pin) const
 	return FText::FromName(Pin->PinName);
 }
 
-void UK2Node_FormatError::PostEditChangeProperty(struct FPropertyChangedEvent& PropertyChangedEvent)
+void UK2Node_FormatMessage::PostEditChangeProperty(struct FPropertyChangedEvent& PropertyChangedEvent)
 {
 	const FName PropertyName = (PropertyChangedEvent.Property  ? PropertyChangedEvent.Property->GetFName() : NAME_None);
-	if (PropertyName == GET_MEMBER_NAME_CHECKED(UK2Node_FormatError, PinNames))
+	if (PropertyName == GET_MEMBER_NAME_CHECKED(UK2Node_FormatMessage, PinNames))
 	{
 		ReconstructNode();
 	}
@@ -238,13 +255,13 @@ void UK2Node_FormatError::PostEditChangeProperty(struct FPropertyChangedEvent& P
 	GetGraph()->NotifyNodeChanged(this);
 }
 
-void UK2Node_FormatError::PinConnectionListChanged(UEdGraphPin* Pin)
+void UK2Node_FormatMessage::PinConnectionListChanged(UEdGraphPin* Pin)
 {
 	Modify();
 	SynchronizeArgumentPinType(Pin);
 }
 
-void UK2Node_FormatError::PinDefaultValueChanged(UEdGraphPin* Pin)
+void UK2Node_FormatMessage::PinDefaultValueChanged(UEdGraphPin* Pin)
 {
 	if(IsFormatPin(Pin))
 	{
@@ -255,19 +272,19 @@ void UK2Node_FormatError::PinDefaultValueChanged(UEdGraphPin* Pin)
 	}
 }
 
-void UK2Node_FormatError::PinTypeChanged(UEdGraphPin* Pin)
+void UK2Node_FormatMessage::PinTypeChanged(UEdGraphPin* Pin)
 {
 	SynchronizeArgumentPinType(Pin);
 	Super::PinTypeChanged(Pin);
 }
 
-FText UK2Node_FormatError::GetTooltipText() const
+FText UK2Node_FormatMessage::GetTooltipText() const
 {
 	return NodeTooltip;
 }
 
 
-void UK2Node_FormatError::PostReconstructNode()
+void UK2Node_FormatMessage::PostReconstructNode()
 {
 	Super::PostReconstructNode();
 
@@ -284,16 +301,21 @@ void UK2Node_FormatError::PostReconstructNode()
 
 // Get a function that can convert the specified type into a FFormatArgumentData.
 //
+// For example:
+//  * if you pass in a pin of type 'String', it will return UlxFormatDataLibrary::FormatArgumentDataString
+//  * if you pass in a pin of type 'Vector', it will return UlxFormatDataLibrary::FormatArgumentDataVector
+//  and so forth.
+//
 UFunction *ToFormatArgumentData(const UEdGraphSchema_K2 *Schema, const FEdGraphPinType& PinType, bool AllowWild)
 {
 	// Special case.  Wildcard Pins are unconnected pins.
 	//
 	if (PinType.PinCategory == UEdGraphSchema_K2::PC_Wildcard && AllowWild)
 	{
-		return UlxFormatDataLibrary::StaticClass()->FindFunctionByName(GET_MEMBER_NAME_CHECKED(UlxFormatDataLibrary, FormatArgumentDataBlank));
+		return UlxBlueprintErrorLibrary::StaticClass()->FindFunctionByName(GET_MEMBER_NAME_CHECKED(UlxBlueprintErrorLibrary, FormatArgumentDataBlank));
 	}
 
-	// Try to find an exact match in the UlxFormatDataLibrary.
+	// Try to find a match in the UlxFormatDataLibrary.
 	//
 	for (auto It = TFieldIterator<UFunction>(UlxFormatDataLibrary::StaticClass()); It; ++It)
 	{
@@ -305,6 +327,14 @@ UFunction *ToFormatArgumentData(const UEdGraphSchema_K2 *Schema, const FEdGraphP
 		if (!Schema->ArePinTypesEquivalent(PinType, ValuePinType)) continue;
 		return Function;
 	}
+	
+	// A general handler for Enums. You can override this for specific enums by
+	// putting that particular enum into the UlxFormatDataLibrary.
+	//
+	if ((PinType.PinCategory == UEdGraphSchema_K2::PC_Byte) && (nullptr != Cast<const UEnum>(PinType.PinSubCategoryObject)))
+	{
+		return UlxBlueprintErrorLibrary::StaticClass()->FindFunctionByName(GET_MEMBER_NAME_CHECKED(UlxBlueprintErrorLibrary, FormatArgumentDataEnum));
+	}
 
 	// A case for subclasses of 'Object' which are not exactly 'Object'
 	//
@@ -320,12 +350,12 @@ UFunction *ToFormatArgumentData(const UEdGraphSchema_K2 *Schema, const FEdGraphP
 	
 	
 
-void UK2Node_FormatError::ExpandNode(class FKismetCompilerContext& CompilerContext, UEdGraph* SourceGraph)
+void UK2Node_FormatMessage::ExpandNode(class FKismetCompilerContext& CompilerContext, UEdGraph* SourceGraph)
 {
 	Super::ExpandNode(CompilerContext, SourceGraph);
 
 	/**
-		At the end of this, the UK2Node_FormatError will not be a part of the Blueprint, it merely handles connecting
+		At the end of this, the UK2Node_FormatMessage will not be a part of the Blueprint, it merely handles connecting
 		the other nodes into the Blueprint.
 	*/
 
@@ -336,9 +366,19 @@ void UK2Node_FormatError::ExpandNode(class FKismetCompilerContext& CompilerConte
 	MakeArrayNode->AllocateDefaultPins();
 	CompilerContext.MessageLog.NotifyIntermediateObjectCreation(MakeArrayNode, this);
 
+	// Decide which formatting function we're going to call.
+	UFunction *FormatFunction;
+	if (IsFormatErrorMessage())
+	{
+		FormatFunction = UlxBlueprintErrorLibrary::StaticClass()->FindFunctionByName(GET_MEMBER_NAME_CHECKED(UlxBlueprintErrorLibrary, FormatErrorInternal));
+	}
+	else
+	{
+		FormatFunction = UKismetTextLibrary::StaticClass()->FindFunctionByName(GET_MEMBER_NAME_CHECKED(UKismetTextLibrary, Format));
+	}
+
 	// This is the node that does all the Format work and outputs the message.
 	UK2Node_CallFunction* CallFormatFunction = CompilerContext.SpawnIntermediateNode<UK2Node_CallFunction>(this, SourceGraph);
-	UFunction *FormatFunction = UlxBlueprintErrorLibrary::StaticClass()->FindFunctionByName(GET_MEMBER_NAME_CHECKED(UlxBlueprintErrorLibrary, FormatErrorInternal));
 	CallFormatFunction->SetFromFunction(FormatFunction);
 	CallFormatFunction->AllocateDefaultPins();
 	CompilerContext.MessageLog.NotifyIntermediateObjectCreation(CallFormatFunction, this);
@@ -372,16 +412,23 @@ void UK2Node_FormatError::ExpandNode(class FKismetCompilerContext& CompilerConte
 		CompilerContext.MessageLog.NotifyIntermediateObjectCreation(ConvertNode, this);
 		UEdGraphPin *ValuePin = ConvertNode->FindPin(TEXT("Value"));
 		UEdGraphPin *NamePin = ConvertNode->FindPinChecked(TEXT("Name"));
+		UEdGraphPin *SubCategoryObjectPin = ConvertNode->FindPin(TEXT("PinSubCategoryObject"));
 
 		// Set a value for the 'Name' pin of the converter.
 		ConvertNode->GetSchema()->TrySetDefaultValue(*NamePin, OriginalName);
 
-		// Connect the Value pin of the converter.
+		// Connect the Value pin of the converter, if any.
 		if (ValuePin != nullptr)
 		{
 			CompilerContext.MovePinLinksToIntermediate(*ArgumentPin, *ValuePin);
 		}
 
+		// If the converter wants to know the PinSubCategoryObject, pass it in.
+		if (SubCategoryObjectPin != nullptr)
+		{
+			SubCategoryObjectPin->DefaultObject = Cast<UObject>(ArgumentPin->PinType.PinSubCategoryObject);
+		}
+
 		// The "Make Array" node already has one pin available, so don't create one for ArgIdx == 0
 		if(ArgIdx > 0)
 		{
@@ -396,11 +443,18 @@ void UK2Node_FormatError::ExpandNode(class FKismetCompilerContext& CompilerConte
 		ConvertNode->GetReturnValuePin()->MakeLinkTo(InputPin);
 	}
 
-	// Move connection of "Format" pin to the call function's "InPattern" pin
+	// Connect up other pins to the Formatting node.
 	CompilerContext.MovePinLinksToIntermediate(*FindPinChecked(FormatPinName), *CallFormatFunction->FindPinChecked(TEXT("InPattern")));
-	CompilerContext.MovePinLinksToIntermediate(*FindPinChecked(VerbosityPinName), *CallFormatFunction->FindPinChecked(TEXT("Verbosity")));
-	CompilerContext.MovePinLinksToIntermediate(*FindPinChecked(DisplayDurationPinName), *CallFormatFunction->FindPinChecked(TEXT("DisplayDuration")));
-	
+	if (IsFormatErrorMessage())
+	{
+		CompilerContext.MovePinLinksToIntermediate(*FindPinChecked(VerbosityPinName), *CallFormatFunction->FindPinChecked(TEXT("Verbosity")));
+		CompilerContext.MovePinLinksToIntermediate(*FindPinChecked(DisplayDurationPinName), *CallFormatFunction->FindPinChecked(TEXT("DisplayDuration")));
+	}
+	else
+	{
+		CompilerContext.MovePinLinksToIntermediate(*FindPinChecked(ResultPinName), *CallFormatFunction->GetReturnValuePin());
+	}
+
 	// Link up the Exec pins.
 	CompilerContext.MovePinLinksToIntermediate(*GetExecPin(), *CallFormatFunction->GetExecPin());
 	CompilerContext.MovePinLinksToIntermediate(*GetThenPin(), *CallFormatFunction->GetThenPin());
@@ -409,7 +463,7 @@ void UK2Node_FormatError::ExpandNode(class FKismetCompilerContext& CompilerConte
 }
 
 
-UK2Node::ERedirectType UK2Node_FormatError::DoPinsMatchForReconstruction(const UEdGraphPin* NewPin, int32 NewPinIndex, const UEdGraphPin* OldPin, int32 OldPinIndex) const
+UK2Node::ERedirectType UK2Node_FormatMessage::DoPinsMatchForReconstruction(const UEdGraphPin* NewPin, int32 NewPinIndex, const UEdGraphPin* OldPin, int32 OldPinIndex) const
 {
 	ERedirectType RedirectType = ERedirectType_None;
 
@@ -454,7 +508,7 @@ UK2Node::ERedirectType UK2Node_FormatError::DoPinsMatchForReconstruction(const U
 	return RedirectType;
 }
 
-bool UK2Node_FormatError::IsConnectionDisallowed(const UEdGraphPin* MyPin, const UEdGraphPin* OtherPin, FString& OutReason) const
+bool UK2Node_FormatMessage::IsConnectionDisallowed(const UEdGraphPin* MyPin, const UEdGraphPin* OtherPin, FString& OutReason) const
 {
 	// The following pins cannot be connected.  They are meant to be hardwired constants.
 	if (IsFormatPin(MyPin))
@@ -481,7 +535,7 @@ bool UK2Node_FormatError::IsConnectionDisallowed(const UEdGraphPin* MyPin, const
 }
 
 
-void UK2Node_FormatError::GetMenuActions(FBlueprintActionDatabaseRegistrar& ActionRegistrar) const
+void UK2Node_FormatMessage::GetMenuActions(FBlueprintActionDatabaseRegistrar& ActionRegistrar) const
 {
 	// actions get registered under specific object-keys; the idea is that 
 	// actions might have to be updated (or deleted) if their object-key is  
@@ -501,10 +555,33 @@ void UK2Node_FormatError::GetMenuActions(FBlueprintActionDatabaseRegistrar& Acti
 	}
 }
 
-FText UK2Node_FormatError::GetMenuCategory() const
+FText UK2Node_FormatMessage::GetMenuCategory() const
 {
 	return FEditorCategoryUtils::GetCommonCategory(FCommonEditorCategory::Text);
 }
 
+UK2Node_FormatMessage::UK2Node_FormatMessage(const FObjectInitializer& ObjectInitializer)
+	: Super(ObjectInitializer)
+{
+	NodeTooltip = LOCTEXT("NodeTooltip", 
+		"Format a message, and output it as Text.\n"
+		"\n"
+		"  \u2022 Use {ArgName} to denote format arguments, giving each argument a different ArgName.\n"
+		"\n"
+		);
+}
+
+UK2Node_FormatErrorMessage::UK2Node_FormatErrorMessage(const FObjectInitializer& ObjectInitializer)
+	: Super(ObjectInitializer)
+{
+	NodeTooltip = LOCTEXT("NodeTooltip", 
+		"Output an error, warning, or informational message to the log file.\n"
+		"\n"
+		"  \u2022 Use {ArgName} to denote format arguments, giving each argument a different ArgName.\n"
+		"\n"
+		"It is often desirable to use this in conjunction with a separate utility that\n"
+		"pauses the execution of the blueprint whenever an error is logged."
+		);
+}
 
 #undef LOCTEXT_NAMESPACE

Source/Integration/FormatError.h

@@ -22,14 +22,21 @@ class FString;
 class UEdGraph;
 class UObject;
 
-
-
-
 //
-// The Format Error Message K2Node.
+// FormatMessage and FormatErrorMessage
+//
+// This file defines two K2Nodes: FormatMessage, and FormatErrorMessage.  The
+// only difference between them is that the former outputs the message as an
+// output pin.  The latter outputs the message to the log instead.
+//
+// To implement code reuse, we put all the code into FormatMessage, and made
+// FormatErrorMessage a derived class of FormatMessage.  The derived class
+// doesn't override anything - all it does is set a flag, the flag changes
+// the behavior of FormatMessage.
+// 
 //
 UCLASS(MinimalAPI)
-class UK2Node_FormatError : public UK2Node
+class UK2Node_FormatMessage : public UK2Node
 {
 	GENERATED_UCLASS_BODY()
 
@@ -60,14 +67,17 @@ class UK2Node_FormatError : public UK2Node
 	virtual int32 GetNodeRefreshPriority() const override { return EBaseNodeRefreshPriority::Low_UsesDependentWildcard; }
 	//~ End UK2Node Interface.
 
-private:
+protected:
 	/** Create all necessary pins */
 	void CreateCorrectPins();
 
 	/** Synchronize the type of the given argument pin with the type its connected to, or reset it to a wildcard pin if there's no connection */
 	void SynchronizeArgumentPinType(UEdGraphPin* Pin);
 
-private:
+	/** Our derived class will set this to true, altering the behavior of this K2Node. **/
+	virtual bool IsFormatErrorMessage() const { return false; }
+
+protected:
 	/** When adding arguments to the node, their names are placed here and are generated as pins during construction */
 	UPROPERTY()
 	TArray<FString> PinNames;
@@ -76,3 +86,18 @@ private:
 	FText NodeTooltip;
 };
 
+
+//
+// This derives from FormatMessage.
+//
+UCLASS(MinimalAPI)
+class UK2Node_FormatErrorMessage : public UK2Node_FormatMessage
+{
+	GENERATED_UCLASS_BODY()
+
+	// Setting this flag alters the behavior of FormatMessage, making it
+	// output to the log instead of to a pin.
+	//
+	virtual bool IsFormatErrorMessage() const override { return true; }
+};
+