4.7 C++ Transition Guide

[Elvince]

Hi,

IOnlineFriends have been changed to add the delegate inside the parameter functions like ReadList..
IChatInterface have been added, so you must implement it in your OSS Class.

I'm still converting my project, but those one were not highlighted in the release notes

Thanks,

[Madness]

Blackboard Key Init

Header.h

uint8 enemyKeyID; // no change

Source.cpp

blackboardComp->SetValueAsObject(enemyKeyID, InPawn);

/* becomes */

#include "BehaviorTree/Blackboard/BlackboardKeyType_Object.h" 
...

blackboardComp->SetValue<UBlackboardKeyType_Object>(enemyKeyID, InPawn);

I don't really understand why they did this , but now you need to include each file for each type (Object , Float , bool ,...)

[DamirH]

Rama,

No reason, I just noted that adding a call to Super() from a default empty constructor makes the editor impossible to launch, that's all.

[xconverge]

Dear DamirH,

Is there a reason you are avoiding the ObjectInitializer constructor?

~~~

4.7 Class Constructors

For those who might be confused about all this:

You can easily create a constructor in 4.7 using this arrangement:

.h

UCLASS()
class AYourClass : public AYourSuperClass
{
	GENERATED_BODY()
public: 
	AYourClass(const FObjectInitializer& ObjectInitializer);

};

.cpp

AYourClass::AYourClass(const FObjectInitializer& ObjectInitializer)
	: Super(ObjectInitializer)
{
   //add your constructor code / other constructor function calls here
}

Enjoy!

Rama

"Creating sub-objects for Unreal classes now has a new simple syntax."

I tried finding some documentation on what this means, but haven't found any luck. Previously in the constructor I was using as you show it with the FObjectInitializer. In the default constructor now without the initializer, how would you create a sub-object? For now I will stick with the old constructor style but was just curious.

[DamirH]

"Creating sub-objects for Unreal classes now has a new simple syntax."

I tried finding some documentation on what this means, but haven't found any luck. Previously in the constructor I was using as you show it with the FObjectInitializer. In the default constructor now without the initializer, how would you create a sub-object? For now I will stick with the old constructor style but was just curious.

There's a post in this thread, just do this:

UCLASS()
class WAPROTOTYPE_API AWaCharacterBase : public ACharacter
{
GENERATED_BODY()

//A bunch of functions and properties

public:
AWaCharacterBase();
}

AWaCharacterBase::AWaCharacterBase()
{
//Constructor code here

}

[kamrann]

I tried finding some documentation on what this means, but haven't found any luck. Previously in the constructor I was using as you show it with the FObjectInitializer. In the default constructor now without the initializer, how would you create a sub-object? For now I will stick with the old constructor style but was just curious.

Just replace

ObjectInitializer.CreateDefaultSubobject< Type >(this, Name);

with

CreateDefaultSubobject< Type >(Name);

[The Beej]

I think you're confused with 'calling' super like this:

AWaCharacterBase::AWaCharacterBase() : Super()
{
    //constructor code
}

This is what you're supposed to do, it specifies which version of the superclass constructor should be called just before this constructor is run. If you are just using the superclass default constructor you don't even need to do : Super(), since it does that by default.

[xconverge]

Just replace

ObjectInitializer.CreateDefaultSubobject< Type >(this, Name);

with

CreateDefaultSubobject< Type >(Name);

thanks! it was the "this" I wasn't omitting, was still using the 2 argument overload

[DamirH]

I think you're confused with 'calling' super like this:

AWaCharacterBase::AWaCharacterBase() : Super()
{
    //constructor code
}

This is what you're supposed to do, it specifies which version of the superclass constructor should be called just before this constructor is run. If you are just using the superclass default constructor you don't even need to do : Super(), since it does that by default.

That was indeed the case. I was under the impression that the two were equivalent to each other.

[KillerPenguin]

'bReplicateInstigator' : undeclared identifier

Guess this one is gone?

warning C4996: 'IOnlineSession::ClearOnCreateSessionCompleteDelegate': The ClearOnCreateSessionCompleteDelegate function is deprecated - please use the AddOnCreateSessionCompleteDelegate_Handle function and pass its return value to ClearOnCreateSessionCompleteDelegate_Handle instead. Please update your code to the new API before upgrading to the next release, otherwise your project will no longer compile.

This one too.. (among many other IOnlineSession codes)

[KillerPenguin]

In 4.7 AAIController::MoveToActor() doesn't really automatically updating its target position like it use to.

I've tested using AAIController::GetImmediateMoveDestination() and it seems to be updating once it reach the first target.
Wierd yet, after that my AI running back and forth between its original position and next points along its path.

[Elvince]

Does someone know why the background of this changes : 'bReplicateInstigator' : undeclared identifier?
What happened to this behavior? Is it acting as True or false?

IOnlineFriends - Watch out, the function signature are not all the same. I mean, that some changed with passing a delegate to it to be called once it's over, and the others still work in the old fashion.
FYI I raised a Answers question on this
It will help to understand where we are going in the future...

[Rama]

Does someone know why the background of this changes : 'bReplicateInstigator' : undeclared identifier?
What happened to this behavior? Is it acting as True or false?

bReplicateInstigator got removed from the engine!

It's in the release notes that they removed certain unused actor replication variables

Have fun today Elvince!



Rama

[Rama]

Bump for those still converting to 4.7

[reinrag]

Heh, reminds me of Blade's Unrealscript upgrade threads before, nice one Rama. Thanks!