Flow subgraph outputs and sequencer

Config/DefaultFlow.ini

@@ -2,3 +2,5 @@
 +ClassRedirects=(OldName="/Script/Flow.FlowNode_CustomEvent",NewName="/Script/Flow.FlowNode_CustomInput")
 +StructRedirects=(OldName="/Script/Flow.FlowNamedDataPinOutputProperty",NewName="/Script/Flow.FlowNamedDataPinProperty")
 +PropertyRedirects=(OldName="FlowNode_DefineProperties.OutputProperties",NewName="NamedProperties")
++FunctionRedirects=(OldName="/Script/Flow.FlowSubsystem.FinishRootFlow",NewName="/Script/Flow.FlowSubsystem.FinishAndDeinitializeRootFlow")
++FunctionRedirects=(OldName="/Script/Flow.FlowSubsystem.FinishAllRootFlows",NewName="/Script/Flow.FlowSubsystem.FinishAndDeinitializeAllRootFlows")

Source/Flow/Private/FlowAsset.cpp

@@ -18,6 +18,7 @@
 #include "Nodes/Graph/FlowNode_SubGraph.h"
 #include "Policies/FlowPinConnectionPolicy.h"
 #include "Policies/FlowPreloadPolicy.h"
+#include "Types/FlowAutoDataPinsWorkingData.h"
 #include "Types/FlowDataPinValue.h"
 #include "Types/FlowStructUtils.h"
 
@@ -914,7 +915,7 @@ void UFlowAsset::ClearInstances()
 	{
 		if (ActiveInstances.IsValidIndex(i) && ActiveInstances[i])
 		{
-			ActiveInstances[i]->FinishFlow(EFlowFinishPolicy::Keep);
+			ActiveInstances[i]->FinishFlowAndDeinitializeInstance(EFlowFinishPolicy::Keep);
 		}
 	}
 
@@ -1046,6 +1047,12 @@ AActor* UFlowAsset::TryFindActorOwner() const
 	return nullptr;
 }
 
+void UFlowAsset::FinishFlowAndDeinitializeInstance(const EFlowFinishPolicy InFinishPolicy)
+{
+	FinishFlow(InFinishPolicy);
+	DeinitializeInstance();
+}
+
 void UFlowAsset::PreStartFlow()
 {
 	ResetNodes();
@@ -1155,13 +1162,14 @@ void UFlowAsset::FinishNode(UFlowNode* Node)
 				return;
 			}
 
-			// if this instance is a Root Flow, we need to deregister it from the subsystem first
+			// if this instance is a Root Flow, we need to deregister it from the subsystem first. This will 
+			// finalize and deinitialize the root flow.
 			if (Owner.IsValid())
 			{
 				const TSet<UFlowAsset*>& RootFlowInstances = GetFlowSubsystem()->GetRootInstancesByOwner(Owner.Get());
 				if (RootFlowInstances.Contains(this))
 				{
-					GetFlowSubsystem()->FinishRootFlow(Owner.Get(), TemplateAsset, EFlowFinishPolicy::Keep);
+					GetFlowSubsystem()->FinishAndDeinitializeRootFlow(Owner.Get(), TemplateAsset, EFlowFinishPolicy::Keep);
 
 					return;
 				}
@@ -1182,7 +1190,7 @@ void UFlowAsset::ResetNodes()
 	RecordedNodes.Empty();
 }
 
-void UFlowAsset::FinishFlow(const EFlowFinishPolicy InFinishPolicy, const bool bRemoveInstance /*= true*/)
+void UFlowAsset::FinishFlow(const EFlowFinishPolicy InFinishPolicy)
 {
 	FinishPolicy = InFinishPolicy;
 
@@ -1193,13 +1201,8 @@ void UFlowAsset::FinishFlow(const EFlowFinishPolicy InFinishPolicy, const bool b
 	{
 		Node->Deactivate();
 	}
-	ActiveNodes.Empty();
 
-	// provides option to finish game-specific logic prior to removing asset instance 
-	if (bRemoveInstance)
-	{
-		DeinitializeInstance();
-	}
+	ActiveNodes.Empty();
 }
 
 UFlowSubsystem* UFlowAsset::GetFlowSubsystem() const
@@ -1248,6 +1251,50 @@ const FFlowPreloadPolicy& UFlowAsset::GetPreloadPolicy() const
 	return PreloadPolicy.Get();
 }
 
+void UFlowAsset::InitializeOutputDataReceiverAndValues(IFlowGraphOutputDataReceiverInterface* InOutputDataReceiver)
+{
+	OutputDataReceiver = Cast<UObject>(InOutputDataReceiver);
+
+	// Initialize the live output store from the template asset's declarations
+	OutputDataPinValues.Values.Reset();
+
+	if (const UFlowAsset* Template = TemplateAsset.Get())
+	{
+		for (const FFlowNamedDataPinProperty& Declaration : Template->OutputDataPinDeclarations)
+		{
+			if (Declaration.IsValid())
+			{
+				OutputDataPinValues.Values.Add(Declaration.Name, Declaration.DataPinValue);
+			}
+			else
+			{
+				UE_LOG(LogFlow, Warning, TEXT("Invalid OutputDataPin %s"), *Declaration.Name.ToString());
+			}
+		}
+	}
+}
+
+void UFlowAsset::WriteOutputDataPinValue(const FName& PinName, const TInstancedStruct<FFlowDataPinValue>& Value)
+{
+	if (OutputDataPinValues.Values.Contains(PinName))
+	{
+		OutputDataPinValues.Values[PinName] = Value;
+	}
+	else
+	{
+		UE_LOG(LogFlow, Warning, TEXT("Could not find pin named %s in WriteOutputDataPinValue"), *PinName.ToString());
+	}
+}
+
+void UFlowAsset::FlushOutputDataPinValuesToReceiver()
+{
+	if (IFlowGraphOutputDataReceiverInterface* Receiver = Cast<IFlowGraphOutputDataReceiverInterface>(OutputDataReceiver.Get()))
+	{
+		// Do an immediate push to the receiver
+		Receiver->ReceiveOutputDataSnapshot(OutputDataPinValues);
+	}
+}
+
 void UFlowAsset::TriggerCustomInput(const FName& EventName, IFlowDataPinValueSupplierInterface* DataPinValueSupplier)
 {
 	for (UFlowNode_CustomInput* CustomInputNode : CustomInputNodes)

Source/Flow/Private/FlowComponent.cpp

@@ -99,7 +99,7 @@ void UFlowComponent::UnregisterWithFlowSubsystem()
 {
 	if (UFlowSubsystem* FlowSubsystem = GetFlowSubsystem())
 	{
-		FlowSubsystem->FinishAllRootFlows(this, EFlowFinishPolicy::Keep);
+		FlowSubsystem->FinishAndDeinitializeAllRootFlows(this, EFlowFinishPolicy::Keep);
 		FlowSubsystem->UnregisterComponent(this);
 	}
 }
@@ -461,7 +461,7 @@ void UFlowComponent::FinishRootFlow(UFlowAsset* TemplateAsset, const EFlowFinish
 {
 	if (UFlowSubsystem* FlowSubsystem = GetFlowSubsystem())
 	{
-		FlowSubsystem->FinishRootFlow(this, TemplateAsset, FinishPolicy);
+		FlowSubsystem->FinishAndDeinitializeRootFlow(this, TemplateAsset, FinishPolicy);
 	}
 }
 

Source/Flow/Private/FlowSubsystem.cpp

@@ -127,7 +127,7 @@ UFlowAsset* UFlowSubsystem::CreateRootFlow(UObject* Owner, UFlowAsset* FlowAsset
 	return NewFlow;
 }
 
-void UFlowSubsystem::FinishRootFlow(UObject* Owner, UFlowAsset* TemplateAsset, const EFlowFinishPolicy FinishPolicy)
+void UFlowSubsystem::FinishAndDeinitializeRootFlow(UObject* Owner, UFlowAsset* TemplateAsset, const EFlowFinishPolicy FinishPolicy)
 {
 	UFlowAsset* InstanceToFinish = nullptr;
 
@@ -143,11 +143,11 @@ void UFlowSubsystem::FinishRootFlow(UObject* Owner, UFlowAsset* TemplateAsset, c
 	if (InstanceToFinish)
 	{
 		RootInstances.Remove(InstanceToFinish);
-		InstanceToFinish->FinishFlow(FinishPolicy);
+		InstanceToFinish->FinishFlowAndDeinitializeInstance(FinishPolicy);
 	}
 }
 
-void UFlowSubsystem::FinishAllRootFlows(UObject* Owner, const EFlowFinishPolicy FinishPolicy)
+void UFlowSubsystem::FinishAndDeinitializeAllRootFlows(UObject* Owner, const EFlowFinishPolicy FinishPolicy)
 {
 	TArray<UFlowAsset*> InstancesToFinish;
 
@@ -162,7 +162,7 @@ void UFlowSubsystem::FinishAllRootFlows(UObject* Owner, const EFlowFinishPolicy
 	for (UFlowAsset* InstanceToFinish : InstancesToFinish)
 	{
 		RootInstances.Remove(InstanceToFinish);
-		InstanceToFinish->FinishFlow(FinishPolicy);
+		InstanceToFinish->FinishFlowAndDeinitializeInstance(FinishPolicy);
 	}
 }
 
@@ -205,6 +205,23 @@ UFlowAsset* UFlowSubsystem::CreateSubFlow(UFlowNode_SubGraph* SubGraphNode, cons
 	return AssetInstance;
 }
 
+void UFlowSubsystem::FinishSubFlow(UFlowNode_SubGraph* SubGraphNode, const EFlowFinishPolicy FinishPolicy)
+{
+	if (InstancedSubFlows.Contains(SubGraphNode))
+	{
+		// The flow asset running on the subgraph node. 
+		UFlowAsset* SubgraphFlowAsset = InstancedSubFlows[SubGraphNode];
+
+		// This is the flow asset that has the subgraph node. Do not confuse with the flow asset that the node is running.
+		// Remove the subgraph flow from the owning flow active subgraph list. 
+		UFlowAsset* SubgraphNodeParentFlow = SubGraphNode->GetFlowAsset();		
+		SubgraphNodeParentFlow->ActiveSubGraphs.Remove(SubGraphNode);
+
+		// Finish the flow but do not remove the instance. 
+		SubgraphFlowAsset->FinishFlow(FinishPolicy);
+	}
+}
+
 void UFlowSubsystem::RemoveSubFlow(UFlowNode_SubGraph* SubGraphNode, const EFlowFinishPolicy FinishPolicy)
 {
 	if (InstancedSubFlows.Contains(SubGraphNode))
@@ -214,7 +231,12 @@ void UFlowSubsystem::RemoveSubFlow(UFlowNode_SubGraph* SubGraphNode, const EFlow
 		SubGraphNode->GetFlowAsset()->ActiveSubGraphs.Remove(SubGraphNode);
 		InstancedSubFlows.Remove(SubGraphNode);
 
-		AssetInstance->FinishFlow(FinishPolicy);
+		if (AssetInstance->IsActive())
+		{
+			AssetInstance->FinishFlow(FinishPolicy);
+		}
+
+		AssetInstance->DeinitializeInstance();		
 
 		// Make sure to set the NodeOwningThisAssetInstance after the FinishFlow call, as it may be needed in the FinishFlow method
 		AssetInstance->NodeOwningThisAssetInstance = nullptr;

Source/Flow/Private/Nodes/Graph/FlowNode_SubGraph.cpp

@@ -100,14 +100,26 @@ void UFlowNode_SubGraph::ExecuteInput(const FName& PinName)
 
 void UFlowNode_SubGraph::Cleanup()
 {
-	if (CanBeAssetInstanced() && GetFlowSubsystem())
+	UFlowSubsystem* FlowSubsystem = GetFlowSubsystem();
+	if (CanBeAssetInstanced() && FlowSubsystem)
 	{
-		GetFlowSubsystem()->RemoveSubFlow(this, EFlowFinishPolicy::Keep);
+		FlowSubsystem->FinishSubFlow(this, EFlowFinishPolicy::Keep);
 	}
 
 	Super::Cleanup();
 }
 
+void UFlowNode_SubGraph::DeinitializeInstance()
+{
+	UFlowSubsystem* FlowSubsystem = GetFlowSubsystem();
+	if (CanBeAssetInstanced() && FlowSubsystem)
+	{
+		FlowSubsystem->RemoveSubFlow(this, EFlowFinishPolicy::Keep);
+	}
+
+	Super::DeinitializeInstance();
+}
+
 void UFlowNode_SubGraph::ForceFinishNode()
 {
 	TriggerFirstOutput(true);
@@ -178,6 +190,11 @@ void UFlowNode_SubGraph::OnLoad_Implementation()
 	}
 }
 
+void UFlowNode_SubGraph::ReceiveOutputDataSnapshot(const FFlowOutputDataPinValues& Snapshot)
+{
+	CachedOutputDataPinValues = Snapshot;
+}
+
 #if WITH_EDITOR
 
 FText UFlowNode_SubGraph::K2_GetNodeTitle_Implementation() const

Source/Flow/Public/FlowAsset.h

@@ -138,6 +138,15 @@ class FLOW_API UFlowAsset : public UObject
 	UPROPERTY()
 	TMap<FGuid, TObjectPtr<UFlowNode>> Nodes;
 
+public:
+	const TArray<FFlowNamedDataPinProperty>& GetOutputDataPinDeclarations() const { return OutputDataPinDeclarations; }
+
+protected:
+	/* Output Data Pins define typed data values that this graph produces when it finishes.
+	* Sub Graph node using this Flow Asset will generate a context Output Data Pin for every entry on this list. */
+	UPROPERTY(EditAnywhere, Category = "Sub Graph")
+	TArray<FFlowNamedDataPinProperty> OutputDataPinDeclarations;
+
 public:
 #if WITH_EDITOR
 	FFlowGraphEvent OnSubGraphReconstructionRequested;
@@ -388,6 +397,8 @@ class FLOW_API UFlowAsset : public UObject
 
 	virtual FName GetInstanceName() const;
 
+	void FinishFlowAndDeinitializeInstance(const EFlowFinishPolicy InFinishPolicy);
+
 	UFlowAsset* GetTemplateAsset() const { return TemplateAsset; }
 
 	/* Object that spawned Root Flow instance, i.e. World Settings or Player Controller.
@@ -425,6 +436,8 @@ class FLOW_API UFlowAsset : public UObject
 	virtual void FinishNode(UFlowNode* Node);
 	void ResetNodes();
 
+	void InitializeOutputDataReceiverAndValues(IFlowGraphOutputDataReceiverInterface* InOutputDataReceiver);
+
 public:
 	virtual void FinishFlow(const EFlowFinishPolicy InFinishPolicy, const bool bRemoveInstance = true);
 

Source/Flow/Public/FlowSubsystem.h

@@ -78,16 +78,21 @@ class FLOW_API UFlowSubsystem : public UGameInstanceSubsystem
 	 * Nodes have opportunity to terminate themselves differently if Flow Graph has been aborted
 	 * Example: Spawn node might despawn all actors if Flow Graph is aborted, not completed */
 	UFUNCTION(BlueprintCallable, Category = "FlowSubsystem", meta = (DefaultToSelf = "Owner"))
-	virtual void FinishRootFlow(UObject* Owner, UFlowAsset* TemplateAsset, const EFlowFinishPolicy FinishPolicy);
+	virtual void FinishAndDeinitializeRootFlow(UObject* Owner, UFlowAsset* TemplateAsset, const EFlowFinishPolicy FinishPolicy);
 
 	/* Finish Policy value is read by Flow Node
 	 * Nodes have opportunity to terminate themselves differently if Flow Graph has been aborted
 	 * Example: Spawn node might despawn all actors if Flow Graph is aborted, not completed */
 	UFUNCTION(BlueprintCallable, Category = "FlowSubsystem", meta = (DefaultToSelf = "Owner"))
-	virtual void FinishAllRootFlows(UObject* Owner, const EFlowFinishPolicy FinishPolicy);
+	virtual void FinishAndDeinitializeAllRootFlows(UObject* Owner, const EFlowFinishPolicy FinishPolicy);
 
 protected:
 	UFlowAsset* CreateSubFlow(UFlowNode_SubGraph* SubGraphNode, const FString& SavedInstanceName = FString(), const bool bPreloading = false);
+
+	/* Finishes the SubFlow running in the SubGraphNode. It does not deinitialize or removes from the internal InstancedSubFlows list */
+	void FinishSubFlow(UFlowNode_SubGraph* SubGraphNode, const EFlowFinishPolicy FinishPolicy);
+
+	/* Removes the Subflow from the InstancedSubFlows list; and Finishes and Deinitializes it. */
 	void RemoveSubFlow(UFlowNode_SubGraph* SubGraphNode, const EFlowFinishPolicy FinishPolicy);
 
 public:

Source/Flow/Public/Nodes/Graph/FlowNode_SubGraph.h

@@ -53,6 +53,10 @@ class FLOW_API UFlowNode_SubGraph
 	FFlowOutputDataPinValues CachedOutputDataPinValues;
 
 protected:
+	// IFlowGraphOutputDataReceiverInterface
+	virtual void ReceiveOutputDataSnapshot(const FFlowOutputDataPinValues& Snapshot) override;
+	// --
+
 	virtual bool CanBeAssetInstanced() const;
 
 public:
@@ -63,6 +67,7 @@ class FLOW_API UFlowNode_SubGraph
 
 	virtual void ExecuteInput(const FName& PinName) override;
 	virtual void Cleanup() override;
+	virtual void DeinitializeInstance() override;
 
 public:
 	virtual void ForceFinishNode() override;