issue-31: Add node to start a game session

AdvancedSessions/Source/AdvancedSessions/Classes/StartSessionCallbackProxyAdvanced.h

@@ -0,0 +1,46 @@
+#pragma once
+
+#include "CoreMinimal.h"
+#include "BlueprintDataDefinitions.h"
+#include "StartSessionCallbackProxyAdvanced.generated.h"
+
+UCLASS(MinimalAPI)
+class UStartSessionCallbackProxyAdvanced : public UOnlineBlueprintCallProxyBase
+{
+	GENERATED_UCLASS_BODY()
+	// Called when the session starts successfully
+	UPROPERTY(BlueprintAssignable)
+	FEmptyOnlineDelegate OnSuccess;
+
+	// Called when there is an error starting the session
+	UPROPERTY(BlueprintAssignable)
+	FEmptyOnlineDelegate OnFailure;
+
+	/**
+	 * Starts a session with the default online subsystem. The session needs to be previously created by calling the "CreateAdvancedSession" node.
+	 * @param WorldContextObject
+	 */
+	UFUNCTION(
+		BlueprintCallable
+		, meta=(BlueprintInternalUseOnly = "true", WorldContext="WorldContextObject")
+		, Category = "Online|AdvancedSessions"
+	)
+	static UStartSessionCallbackProxyAdvanced* StartAdvancedSession(const UObject* WorldContextObject);
+
+	// UOnlineBlueprintCallProxyBase interface
+	virtual void Activate() override;
+	// End of UOnlineBlueprintCallProxyBase interface
+
+private:
+	// Internal callback when session start completes
+	void OnStartCompleted(FName SessionName, bool bWasSuccessful);
+
+	// The delegate executed by the online subsystem
+	FOnStartSessionCompleteDelegate StartCompleteDelegate;
+
+	// Handles to the registered delegates above
+	FDelegateHandle StartCompleteDelegateHandle;
+
+	// The world context object in which this call is taking place
+	const UObject* WorldContextObject;
+};

AdvancedSessions/Source/AdvancedSessions/Private/StartSessionCallbackProxyAdvanced.cpp

@@ -0,0 +1,62 @@
+#include "StartSessionCallbackProxyAdvanced.h"
+
+UStartSessionCallbackProxyAdvanced::UStartSessionCallbackProxyAdvanced(const FObjectInitializer& ObjectInitializer)
+	: Super(ObjectInitializer)
+	  , StartCompleteDelegate(FOnStartSessionCompleteDelegate::CreateUObject(this, &ThisClass::OnStartCompleted))
+{
+}
+
+UStartSessionCallbackProxyAdvanced* UStartSessionCallbackProxyAdvanced::StartAdvancedSession(
+	const UObject* WorldContextObject)
+{
+	UStartSessionCallbackProxyAdvanced* Proxy = NewObject<UStartSessionCallbackProxyAdvanced>();
+	Proxy->WorldContextObject = WorldContextObject;
+	return Proxy;
+}
+
+void UStartSessionCallbackProxyAdvanced::Activate()
+{
+	const FOnlineSubsystemBPCallHelperAdvanced Helper(
+		TEXT("StartSession"),
+		GEngine->GetWorldFromContextObject(WorldContextObject, EGetWorldErrorMode::LogAndReturnNull));
+
+	if (Helper.OnlineSub != nullptr)
+	{
+		const auto Sessions = Helper.OnlineSub->GetSessionInterface();
+		if (Sessions.IsValid())
+		{
+			StartCompleteDelegateHandle = Sessions->AddOnStartSessionCompleteDelegate_Handle(StartCompleteDelegate);
+			Sessions->StartSession(NAME_GameSession);
+			return;
+		}
+		FFrame::KismetExecutionMessage(TEXT("Sessions not supported by Online Subsystem"), ELogVerbosity::Warning);
+	}
+
+	// Fail immediately
+	OnFailure.Broadcast();
+}
+
+void UStartSessionCallbackProxyAdvanced::OnStartCompleted(FName SessionName, bool bWasSuccessful)
+{
+	const FOnlineSubsystemBPCallHelperAdvanced Helper(
+		TEXT("StartSessionCallback"),
+		GEngine->GetWorldFromContextObject(WorldContextObject, EGetWorldErrorMode::LogAndReturnNull));
+
+	if (Helper.OnlineSub != nullptr)
+	{
+		const auto Sessions = Helper.OnlineSub->GetSessionInterface();
+		if (Sessions.IsValid())
+		{
+			Sessions->ClearOnStartSessionCompleteDelegate_Handle(StartCompleteDelegateHandle);
+		}
+	}
+
+	if (bWasSuccessful)
+	{
+		OnSuccess.Broadcast();
+	}
+	else
+	{
+		OnFailure.Broadcast();
+	}
+}