integration/Source/Integration/BlueprintErrors.h

//
// BlueprintErrors: Better error handling for blueprint errors.
//

#pragma once

#include "Containers/Array.h"
#include "CoreMinimal.h"
#include "InputCoreTypes.h"
#include "HAL/Platform.h"
#include "Misc/OutputDeviceError.h"
#include "UObject/NameTypes.h"
#include "UObject/ObjectMacros.h"
#include "UObject/UObjectGlobals.h"
#include "Kismet/BlueprintFunctionLibrary.h"

#include "BlueprintErrors.generated.h"

class UlxLuaValues;

/* 
 * enum class ElxLogVerbosity, below, contains all the same error severity levels
 * as ELogVerbosity, but in a form that the blueprint editor can manipulate.
 *
 * We deliberately moved 'Fatal' to the end of the list, and made 'Error' option 0.
 * We did that because we want the editor to default to 'Error' in most cases.
 * Unfortunately, that means the numeric values of the two enums don't match up,
 * so we will need a conversion function.
 * 
 */


/** Log Verbosity: The importance of an error message, which affects which logs the error
 *  message gets written to, and how that message gets filtered.
 * 
 */
UENUM(BlueprintType)
enum class ElxLogVerbosity : uint8 {

	/* Prints an error to the console and log file. The editor collects and reports errors. */
	Error,

	/* Prints a warning to the console and log file. The editor collects and report warnings. */
	Warning,

	/* Prints a message to the console and log file. */
	Display,

	/* Prints a message to the log file, however, it does not print to the console. */
	Log,

	/* Prints a message to a log file only if Verbose logging is enabled for the given category. This is usually used for detailed logging. */
	Verbose,

	/* Prints a message to a log file. If VeryVerbose logging is enabled, then this is used for detailed logging that would otherwise spam output. */
	VeryVerbose,

	/* Danger! Prints a fatal error to the console and log file, then crashes (this crashes the editor too). */
	Fatal,
};

/* A library containing assorted useful functions for blueprint error handling.
 *
 */
UCLASS(MinimalAPI)
class UlxBlueprintErrorLibrary : public UBlueprintFunctionLibrary
{
	GENERATED_BODY()

public:
    // The Format Error Message blueprint node macroexpands, the following
    // function is the core of the expansion.  The actual K2Node itself is in
    // its own source file.
    //
	UFUNCTION(BlueprintCallable, meta=(WorldContext = "Context", BlueprintInternalUseOnly = "true"))
	static void FormatErrorInternal(UObject *Context, ElxLogVerbosity Verbosity, 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);
};

/*
 * A library that contains functions that convert data into FFormatArgumentData
 * structs, so that the data can be passed to FText::Format.
 */
UCLASS(MinimalAPI)
class UlxFormatDataLibrary : public UBlueprintFunctionLibrary
{
	GENERATED_BODY()

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);

	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
	static FFormatArgumentData FormatArgumentDataInt64(int64 Value, const FString &Name);

	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
	static FFormatArgumentData FormatArgumentDataFloat(float Value, const FString &Name);

	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
	static FFormatArgumentData FormatArgumentDataDouble(double Value, const FString &Name);

	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
	static FFormatArgumentData FormatArgumentDataText(FText Value, const FString &Name);

	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
	static FFormatArgumentData FormatArgumentDataString(FString Value, const FString &Name);

	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
	static FFormatArgumentData FormatArgumentDataName(FName Value, const FString &Name);

	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
	static FFormatArgumentData FormatArgumentDataKey(FKey Value, const FString &Name);

	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
	static FFormatArgumentData FormatArgumentDataGender(ETextGender Value, const FString &Name);

	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
	static FFormatArgumentData FormatArgumentDataObject(UObject *Value, const FString &Name);

	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
	static FFormatArgumentData FormatArgumentDataVector(const FVector &Value, const FString &Name);

	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
	static FFormatArgumentData FormatArgumentDataVector2D(const FVector2D &Value, const FString &Name);

	UFUNCTION(BlueprintPure, meta = (BlueprintInternalUseOnly = "true"), Category = "Luprex|Utility")
	static FFormatArgumentData FormatArgumentDataRotator(const FRotator &Value, const FString &Name);

	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 FormatArgumentDataLuaValues(const UlxLuaValues *Value, const FString &Name);
};

/* Debug Blueprint Errors output device. 
 *
 * When an error message gets written to the log, using "Format Error Message,"
 * or any other means that writes an error message to the log,
 * we can optionally notify the blueprint debugger to pause execution.
 * This only affects errors that are generated during blueprint execution.
 * Errors in other threads do not pause the blueprint.
 *
 */
struct FlxDebugBlueprintErrorsOutputDevice : public FOutputDevice
{
public:
    // The constructor and destructor automatically register this output device with GLog.
    //
    // This struct doesn't store the sensitivity threshold.  It relies on some blueprint
    // class to do that, so that the threshold can be easily edited with the blueprint
    // editor.  This struct must be initialized with a reference to the threshold variable.
    //
    FlxDebugBlueprintErrorsOutputDevice(const ElxLogVerbosity &SensitivityRef);
    ~FlxDebugBlueprintErrorsOutputDevice();

    // Inspect a log message.
    //
    INTEGRATION_API virtual void Serialize(const TCHAR* V, ELogVerbosity::Type Verbosity, const FName& Category) override;

    // If the device is marked 'CanBeUsedOnMultipleThreads,' then UE_LOG will
    // call Serialize from the current thread, otherwise, it will call Serialize from
    // the logging thread.  Using the logging thread would defeat the purpose of this
    // device, so it's imperative that we set this flag.
    //
    INTEGRATION_API virtual bool CanBeUsedOnMultipleThreads() const override { return true; }

private:
    const ElxLogVerbosity &Sensitivity;
};