The SpawnNow method was simplified to only handle spawning, without c…

…allbacks, reducing code complexity and potential errors in child factories.

Source/PoolManager/Private/Factories/PoolFactory_Actor.cpp

@@ -28,9 +28,6 @@ UObject* UPoolFactory_Actor::SpawnNow_Implementation(const FSpawnRequest& Reques
 	UWorld* World = GetWorld();
 	checkf(World, TEXT("ERROR: [%i] %s:\n'World' is null!"), __LINE__, *FString(__FUNCTION__));
 
-	const TSubclassOf<AActor> ClassToSpawn = const_cast<UClass*>(Request.Class.Get());
-	checkf(ClassToSpawn, TEXT("ERROR: [%i] %s:\n'ClassToSpawn' is null!"), __LINE__, *FString(__FUNCTION__));
-
 	FActorSpawnParameters SpawnParameters;
 	SpawnParameters.OverrideLevel = World->PersistentLevel; // Always keep new objects on Persistent level
 	SpawnParameters.SpawnCollisionHandlingOverride = ESpawnActorCollisionHandlingMethod::AlwaysSpawn;
@@ -40,31 +37,16 @@ UObject* UPoolFactory_Actor::SpawnNow_Implementation(const FSpawnRequest& Reques
 	SpawnParameters.bCreateActorPackage = false; // Do not bake this runtime actor into World Partition level
 #endif
 
-	AActor* NewActor = World->SpawnActor(ClassToSpawn, &Request.Transform, SpawnParameters);
-	checkf(NewActor, TEXT("ERROR: [%i] %s:\n'NewActor' was not spawned!"), __LINE__, *FString(__FUNCTION__));
-
-	FPoolObjectData PoolObjectData;
-	PoolObjectData.bIsActive = true;
-	PoolObjectData.PoolObject = NewActor;
-	PoolObjectData.Handle = Request.Handle;
-
-	if (Request.Callbacks.OnPreRegistered != nullptr)
-	{
-		Request.Callbacks.OnPreRegistered(PoolObjectData);
-	}
-
-	if (AActor* SpawnedActor = Cast<AActor>(NewActor))
-	{
-		// Call construction script since it was delayed before to add it to the pool first
-		SpawnedActor->FinishSpawning(Request.Transform);
-	}
+	return World->SpawnActor(Request.GetClassChecked<AActor>(), &Request.Transform, SpawnParameters);
+}
 
-	if (Request.Callbacks.OnPostSpawned != nullptr)
-	{
-		Request.Callbacks.OnPostSpawned(PoolObjectData);
-	}
+// Is overridden to finish spawning the actor since it was deferred
+void UPoolFactory_Actor::OnPreRegistered(const FSpawnRequest& Request, const FPoolObjectData& ObjectData)
+{
+	Super::OnPreRegistered(Request, ObjectData);
 
-	return NewActor;
+	AActor& SpawnedActor = ObjectData.GetChecked<AActor>();
+	SpawnedActor.FinishSpawning(Request.Transform);
 }
 
 /*********************************************************************************************

Source/PoolManager/Private/Factories/PoolFactory_UObject.cpp

@@ -9,6 +9,10 @@
 //---
 #include UE_INLINE_GENERATED_CPP_BY_NAME(PoolFactory_UObject)
 
+/*********************************************************************************************
+ * Creation
+ ********************************************************************************************* */
+
 // Method to queue object spawn requests
 void UPoolFactory_UObject::RequestSpawn_Implementation(const FSpawnRequest& Request)
 {
@@ -32,29 +36,6 @@ void UPoolFactory_UObject::RequestSpawn_Implementation(const FSpawnRequest& Requ
 	}
 }
 
-// Method to immediately spawn requested object
-UObject* UPoolFactory_UObject::SpawnNow_Implementation(const FSpawnRequest& Request)
-{
-	UObject* CreatedObject = NewObject<UObject>(GetOuter(), Request.Class);
-
-	FPoolObjectData PoolObjectData;
-	PoolObjectData.bIsActive = true;
-	PoolObjectData.PoolObject = CreatedObject;
-	PoolObjectData.Handle = Request.Handle;
-
-	if (Request.Callbacks.OnPreRegistered != nullptr)
-	{
-		Request.Callbacks.OnPreRegistered(PoolObjectData);
-	}
-
-	if (Request.Callbacks.OnPostSpawned != nullptr)
-	{
-		Request.Callbacks.OnPostSpawned(PoolObjectData);
-	}
-
-	return CreatedObject;
-}
-
 // Removes the first spawn request from the queue and returns it
 bool UPoolFactory_UObject::DequeueSpawnRequest(FSpawnRequest& OutRequest)
 {
@@ -90,6 +71,30 @@ bool UPoolFactory_UObject::DequeueSpawnRequestByHandle(const FPoolObjectHandle&
 	return OutRequest.IsValid();
 }
 
+// Method to immediately spawn requested object
+UObject* UPoolFactory_UObject::SpawnNow_Implementation(const FSpawnRequest& Request)
+{
+	return NewObject<UObject>(GetOuter(), Request.GetClassChecked());
+}
+
+// Notifies all listeners that the object is about to be spawned
+void UPoolFactory_UObject::OnPreRegistered(const FSpawnRequest& Request, const FPoolObjectData& ObjectData)
+{
+	if (Request.Callbacks.OnPreRegistered != nullptr)
+	{
+		Request.Callbacks.OnPreRegistered(ObjectData);
+	}
+}
+
+// Notifies all listeners that the object is spawned
+void UPoolFactory_UObject::OnPostSpawned(const FSpawnRequest& Request, const FPoolObjectData& ObjectData)
+{
+	if (Request.Callbacks.OnPostSpawned != nullptr)
+	{
+		Request.Callbacks.OnPostSpawned(ObjectData);
+	}
+}
+
 // Is called on next frame to process a chunk of the spawn queue
 void UPoolFactory_UObject::OnNextTickProcessSpawn_Implementation()
 {
@@ -104,7 +109,16 @@ void UPoolFactory_UObject::OnNextTickProcessSpawn_Implementation()
 		FSpawnRequest OutRequest;
 		if (DequeueSpawnRequest(OutRequest))
 		{
-			SpawnNow(OutRequest);
+			UObject* CreatedObject = SpawnNow(OutRequest);
+			checkf(CreatedObject, TEXT("ERROR: [%i] %hs:\n'CreatedObject' is failed to spawn!"), __LINE__, __FUNCTION__);
+
+			FPoolObjectData ObjectData;
+			ObjectData.bIsActive = true;
+			ObjectData.PoolObject = CreatedObject;
+			ObjectData.Handle = OutRequest.Handle;
+
+			OnPreRegistered(OutRequest, ObjectData);
+			OnPostSpawned(OutRequest, ObjectData);
 		}
 	}
 
@@ -118,6 +132,10 @@ void UPoolFactory_UObject::OnNextTickProcessSpawn_Implementation()
 	}
 }
 
+/*********************************************************************************************
+ * Destruction
+ ********************************************************************************************* */
+
 // Method to destroy given object
 void UPoolFactory_UObject::Destroy_Implementation(UObject* Object)
 {

Source/PoolManager/Public/Factories/PoolFactory_Actor.h

@@ -17,6 +17,9 @@ class POOLMANAGER_API UPoolFactory_Actor : public UPoolFactory_UObject
 {
 	GENERATED_BODY()
 
+	/*********************************************************************************************
+	 * Setup overrides
+	 ********************************************************************************************* */
 public:
 	/** Is overridden to handle Actors-inherited classes. */
 	virtual const UClass* GetObjectClass_Implementation() const override;
@@ -28,6 +31,9 @@ class POOLMANAGER_API UPoolFactory_Actor : public UPoolFactory_UObject
 	/** Is overridden to spawn actors using its engine's Spawn Actor method. */
 	virtual UObject* SpawnNow_Implementation(const FSpawnRequest& Request) override;
 
+	/** Is overridden to finish spawning the actor since it was deferred. */
+	virtual void OnPreRegistered(const FSpawnRequest& Request, const FPoolObjectData& ObjectData) override;
+
 	/*********************************************************************************************
 	 * Destruction
 	 ********************************************************************************************* */
@@ -44,7 +50,7 @@ class POOLMANAGER_API UPoolFactory_Actor : public UPoolFactory_UObject
 
 	/** Is overridden to reset transform to the actor before returning the object to its pool. */
 	virtual void OnReturnToPool_Implementation(UObject* Object) override;
-	
+
 	/** Is overridden to change visibility, collision, ticking, etc. according new state. */
 	virtual void OnChangedStateInPool_Implementation(EPoolObjectState NewState, UObject* InObject) override;
 };

Source/PoolManager/Public/Factories/PoolFactory_UObject.h

@@ -25,32 +25,38 @@ class POOLMANAGER_API UPoolFactory_UObject : public UObject
 {
 	GENERATED_BODY()
 
+	/*********************************************************************************************
+	 * Setup overrides
+	 ********************************************************************************************* */
 public:
-	/** Returns the class of object that this factory will create and manage.
-	 * Has to be overridden by child classes if it wants to handle logic for specific class and its children.
+	/** OVERRIDE by child class to return the class of an object that this factory will create and manage.
 	 * E.g: UObject for UPoolFactory_UObject, AActor for UPoolFactory_Actor, UWidget for UPoolFactory_Widget etc. */
 	UFUNCTION(BlueprintNativeEvent, BlueprintPure, Category = "Pool Factory")
 	const UClass* GetObjectClass() const;
 	virtual FORCEINLINE const UClass* GetObjectClass_Implementation() const { return UObject::StaticClass(); }
 
 	/*********************************************************************************************
 	 * Creation
+	 * RequestSpawn -> DequeueSpawnRequest -> SpawnNow -> OnPreRegistered -> OnPostSpawned
 	 ********************************************************************************************* */
 public:
-	/** Method to queue object spawn requests. */
+	/** Method to queue object spawn requests.
+	 * Is called from UPoolManagerSubsystem::CreateNewObjectInPool. */
 	UFUNCTION(BlueprintNativeEvent, Blueprintable, Category = "Pool Factory", meta = (AutoCreateRefTerm = "Request"))
 	void RequestSpawn(const FSpawnRequest& Request);
 	virtual void RequestSpawn_Implementation(const FSpawnRequest& Request);
 
-	/** Method to immediately spawn requested object. */
+	/** Removes the first spawn request from the queue and returns it.
+	 * Is called after 'RequestSpawn'. */
+	UFUNCTION(BlueprintCallable, Category = "Pool Factory")
+	virtual bool DequeueSpawnRequest(FSpawnRequest& OutRequest);
+
+	/** Method to immediately spawn requested object.
+	 * Is called after 'DequeueSpawnRequest'. */
 	UFUNCTION(BlueprintNativeEvent, BlueprintCallable, Category = "Pool Factory", meta = (AutoCreateRefTerm = "Request"))
 	UObject* SpawnNow(const FSpawnRequest& Request);
 	virtual UObject* SpawnNow_Implementation(const FSpawnRequest& Request);
 
-	/** Removes the first spawn request from the queue and returns it. */
-	UFUNCTION(BlueprintCallable, Category = "Pool Factory")
-	virtual bool DequeueSpawnRequest(FSpawnRequest& OutRequest);
-
 	/** Alternative method to remove specific spawn request from the queue and returns it. */
 	UFUNCTION(BlueprintCallable, Category = "Pool Factory")
 	virtual bool DequeueSpawnRequestByHandle(const FPoolObjectHandle& Handle, FSpawnRequest& OutRequest);
@@ -59,6 +65,16 @@ class POOLMANAGER_API UPoolFactory_UObject : public UObject
 	UFUNCTION(BlueprintPure, Category = "Pool Factory")
 	virtual FORCEINLINE bool IsSpawnQueueEmpty() const { return SpawnQueueInternal.IsEmpty(); }
 
+	/** Is called right after object is spawned and before it is registered in the Pool.
+	 * Is called after 'SpawnNow'. */
+	UFUNCTION(BlueprintCallable, Category = "C++")
+	virtual void OnPreRegistered(const FSpawnRequest& Request, const FPoolObjectData& ObjectData);
+
+	/** Is called right after object is spawned and registered in the Pool.
+	 * Is called after 'OnPreRegistered'. */
+	UFUNCTION(BlueprintCallable, Category = "C++")
+	virtual void OnPostSpawned(const FSpawnRequest& Request, const FPoolObjectData& ObjectData);
+
 protected:
 	/** Is called on next frame to process a chunk of the spawn queue. */
 	UFUNCTION(BlueprintNativeEvent, BlueprintCallable, Category = "Pool Factory", meta = (BlueprintProtected))

Source/PoolManager/Public/PoolManagerTypes.h

@@ -5,6 +5,7 @@
 #include "UObject/Object.h"
 //---
 #include "Misc/Guid.h"
+#include "Templates/NonNullSubclassOf.h"
 //---
 #include "PoolManagerTypes.generated.h"
 
@@ -210,4 +211,8 @@ struct POOLMANAGER_API FSpawnRequest
 
 	/** Returns true if this spawn request can be processed. */
 	FORCEINLINE bool IsValid() const { return Class && Handle.IsValid(); }
+
+	/** Returns requested class or crashes if it is not set or can't be casted to the specified type. */ 
+	template <typename T = UObject>
+	FORCEINLINE TNonNullSubclassOf<T> GetClassChecked() const { return TNonNullSubclassOf<T>(const_cast<UClass*>(Class.Get())); }
 };