Progress on Content Tag Registry implementation, currently only with …

…manual tag add calls. Testing usage in ExampleMod to be removed later

Mods/SML/SML.uplugin

@@ -3,7 +3,7 @@
 	"Version": 3,
 	"VersionName": "3.7.0",
 	"SemVersion": "3.7.0",
-	"GameVersion": "269772",
+	"GameVersion": ">=269772",
 	"FriendlyName": "Satisfactory Mod Loader",
 	"Description": "Mod loading and compatibility API for Satisfactory",
 	"Category": "Modding",
@@ -36,4 +36,4 @@
 			"BasePlugin": true
 		}
 	]
-}
+}

Mods/SML/Source/SML/Private/Registry/ContentTagRegistry.cpp

@@ -0,0 +1,98 @@
+#include "Registry/ContentTagRegistry.h"
+
+#include "ModLoading/PluginModuleLoader.h"
+
+DEFINE_LOG_CATEGORY(LogContentTagRegistry);
+
+FFrame* UContentTagRegistry::ActiveScriptFramePtr{};
+
+/** Makes sure provided object instance is valid, crashes with both script call stack and native stack trace if it's not */
+#define NOTIFY_INVALID_REGISTRATION(Context) \
+	{ \
+		/* Attempt to use cached script frame pointer first, then fallback to global script callstack (which is not available in shipping by default) */ \
+		const FString ScriptCallstack = UContentTagRegistry::GetCallStackContext(); \
+		UE_LOG(LogContentTagRegistry, Error, TEXT("Attempt to modify content tags failed: %s"), Context); \
+		UE_LOG(LogContentTagRegistry, Error, TEXT("Script Callstack: %s"), *ScriptCallstack); \
+		ensureMsgf( false, TEXT("%s"), *Context ); \
+	} \
+
+UContentTagRegistry::UContentTagRegistry() {
+}
+
+UContentTagRegistry* UContentTagRegistry::Get(const UObject* WorldContext) {
+	if (const UWorld* World = GEngine->GetWorldFromContextObject(WorldContext, EGetWorldErrorMode::ReturnNull)) {
+		return World->GetSubsystem<UContentTagRegistry>();
+	}
+	return nullptr;
+}
+
+const FGameplayTagContainer UContentTagRegistry::GetGameplayTagContainerFor(const UObject* content) {
+	const auto record = TagContainerRegistry.Find(content);
+	return (record == nullptr) ? FGameplayTagContainer() : *record;
+}
+
+bool UContentTagRegistry::CanModifyTagsOf(UObject* content, FString& OutMessage) {
+	if (bRegistryFrozen) {
+		OutMessage = FString::Printf(TEXT("Attempt to modify content tags of object '%s' in frozen registry. Make sure your tag changes are happening in the 'Initialization' Lifecycle Phase and not 'Post Initialization'. TODO update this message with the timing we decide on."), *GetPathNameSafe(content));
+		return false;
+	}
+	if (!IsValid(content)) {
+		OutMessage = FString::Printf(TEXT("Attempt to modify content tags of an invalid object."));
+		return false;
+	}
+	// TODO checking to make sure a UClass is being registered and not a joe schmoe arbitrary uobject instance
+	return true;
+}
+
+void UContentTagRegistry::AddGameplayTagsTo(UObject* content, const FGameplayTagContainer tags) {
+	FString Context;
+	if (!CanModifyTagsOf(content, Context)) {
+		NOTIFY_INVALID_REGISTRATION(*Context);
+		return;
+	}
+	auto& record = TagContainerRegistry.FindOrAdd(content);
+	UE_LOG(LogContentTagRegistry, Verbose, TEXT("Adding tags %s for class %s"), *tags.ToString(), *GetFullNameSafe(content));
+	record.AppendTags(tags);
+}
+
+void UContentTagRegistry::FreezeRegistry() {
+	bRegistryFrozen = true;
+}
+
+bool UContentTagRegistry::ShouldCreateSubsystem(UObject* Outer) const {
+	UWorld* WorldOuter = CastChecked<UWorld>(Outer);
+	return FPluginModuleLoader::ShouldLoadModulesForWorld(WorldOuter);
+}
+
+void UContentTagRegistry::OnActorPreSpawnInitialization(AActor* Actor) {
+	OnWorldBeginPlayDelegate.AddWeakLambda(this, [&]() {
+		FreezeRegistry();
+	});
+}
+
+void UContentTagRegistry::OnWorldBeginPlay(UWorld& InWorld) {
+	OnWorldBeginPlayDelegate.Broadcast();
+}
+
+FString UContentTagRegistry::GetCallStackContext() {
+	// Prefer script callstack to the native one
+	if (ActiveScriptFramePtr != nullptr) {
+		return ActiveScriptFramePtr->Node->GetPathName();
+	}
+
+	// Attempt to capture stack trace
+	TArray<FProgramCounterSymbolInfo> NativeStackTrace = FPlatformStackWalk::GetStack(1, 10);
+	if (NativeStackTrace.IsEmpty()) {
+		FProgramCounterSymbolInfo& Info = NativeStackTrace.Emplace_GetRef();
+		TCString<ANSICHAR>::Strcpy(Info.Filename, FProgramCounterSymbolInfo::MAX_NAME_LENGTH, "Unknown");
+		Info.LineNumber = 1;
+	}
+
+	// Find first frame that does not contain internal logic of content registry
+	int32 FirstExternalFrameIndex = 0;
+	while (FirstExternalFrameIndex + 1 < NativeStackTrace.Num() &&
+		FCStringAnsi::Strifind(NativeStackTrace[FirstExternalFrameIndex].Filename, __FILE__) != nullptr) {
+		FirstExternalFrameIndex++;
+	}
+	return FString::Printf(TEXT("%hs:%d"), NativeStackTrace[FirstExternalFrameIndex].Filename, NativeStackTrace[FirstExternalFrameIndex].LineNumber);
+}

Mods/SML/Source/SML/Public/Registry/ContentTagRegistry.h

@@ -0,0 +1,78 @@
+#pragma once
+
+#include "CoreMinimal.h"
+#include "Subsystems/WorldSubsystem.h"
+#include "GameplayTagContainer.h"
+#include "ContentTagRegistry.generated.h"
+
+DECLARE_LOG_CATEGORY_EXTERN(LogContentTagRegistry, Log, All);
+
+/**
+ * Manages Gameplay Tag Containers for content classes.
+ * Enables any mod to apply Unreal Gameplay Tags to any mod's content,
+ * or the base game's content, at the UClass level.
+ * 
+ * Add tags to content via this registry's provided avenues,
+ * all returned tag containers are const.
+ * 
+ * Tag associations can only be made before save is loaded,
+ * after that moment the registry is frozen and no changes can be made after that.
+ */
+UCLASS()
+class SML_API UContentTagRegistry : public UWorldSubsystem
+{
+	GENERATED_BODY()
+public:
+	UContentTagRegistry();
+
+	/** Retrieves content tag registry instance */
+	UFUNCTION(BlueprintPure, Category = "Content Tag Registry", DisplayName = "GetContentTagRegistry", meta = (WorldContext = "WorldContext"))
+	static UContentTagRegistry* Get(const UObject* WorldContext);
+
+	/**
+	 * Get Gameplay Tag container for the supplied class.
+	 * Could be empty if there were no tags registered.
+	 * TODO outvar bool for found/not?
+	 */
+	UFUNCTION(BlueprintPure, Category = "Content Tag Registry")
+	const FGameplayTagContainer GetGameplayTagContainerFor(const UObject* content);
+
+	/**
+	 * Register gameplay tags from the passed container to the passed class
+	 * TODO FName InRegistrationPluginName?
+	 */
+	UFUNCTION(BlueprintCallable, Category = "Content Tag Registry")
+	void AddGameplayTagsTo(UObject* content, FGameplayTagContainer tags);
+
+	// TODO ability to remove tags
+
+	// TODO auto register of stuff with ExtendedAttributeProvider being registered in mod content registry
+
+	// Freezes the registry. No new registrations are accepted past this point.
+	void FreezeRegistry();
+
+	void OnActorPreSpawnInitialization(AActor* Actor);
+
+	// Begin USubsystem interface
+	virtual bool ShouldCreateSubsystem(UObject* Outer) const override;
+	//virtual void Initialize(FSubsystemCollectionBase& Collection) override;
+	virtual void OnWorldBeginPlay(UWorld& InWorld) override;
+	// End USubsystem interface
+
+private:
+	UPROPERTY()
+	TMap<UObject*, FGameplayTagContainer> TagContainerRegistry;
+
+	bool bRegistryFrozen{ false };
+
+	DECLARE_MULTICAST_DELEGATE(FOnWorldBeginPlay);
+	FOnWorldBeginPlay OnWorldBeginPlayDelegate;
+
+	static FString GetCallStackContext();
+
+	/** Pointer to the currently active script callstack frame, used for debugging purposes */
+	static FFrame* ActiveScriptFramePtr;
+
+	bool CanModifyTagsOf(UObject* content, FString& OutMessage);
+
+};

Mods/SML/Source/SML/Public/Registry/ModContentRegistry.h

@@ -283,6 +283,7 @@ class SML_API UModContentRegistry : public UWorldSubsystem {
 	virtual void Initialize(FSubsystemCollectionBase& Collection) override;
 	virtual void OnWorldBeginPlay(UWorld& InWorld) override;
 	// End USubsystem interface
+
 	static void AddReferencedObjects(UObject* InThis, FReferenceCollector& Collector);
 private:
 	friend class FGameObjectRegistryState;

Mods/SML/Source/SML/Public/Registry/SMLExtendedAttributeProvider.h

@@ -22,7 +22,8 @@ class SML_API ISMLExtendedAttributeProvider {
     GENERATED_BODY()
 public:
 
-    /** Get the Gameplay Tags container for this asset.
+    /**
+    * Get the Gameplay Tags container for this asset.
     * Remember, since it's a BlueprintNativeEvent, to call from C++ you must call via ISMLExtendedAttributeProvider::Execute_GetGameplayTagsContainer
     */
     UFUNCTION(BlueprintNativeEvent, BlueprintCallable, Category="SML|Tags")