How can I access to Description of a BP Variable in C++?

[chepiok_pro (Chepiok)]

I have a C++ Actor class (that inherit from AActor). Some Actor BP subclass my C++ actor. I doing some introspection on FProperty in C++ => How can I access to the variable description (ie. the text used for the variable tooltip) that may have been entered in BP?

[Extrone (Arjun Subhash)]

I think you just have to add a comment right above the UPROPERTY, that shows up as the tooltip in editor (not 100% sure)

[Chatouille]

This is not in the FProperty framework.
Blueprint variables are stored in the Blueprint skeleton, more precisely in UBlueprint->NewVariables. They are a struct of type FBPVariableDescription. In this struct there is an array of metadata entries (of type FBPVariableMetaDataEntry). This is where the description is stored.
Sample code :

UBlueprint* Bp = LoadObject<UBlueprint>(nullptr, TEXT("/Game/Haiyaaa.Haiyaaa"));
for (auto& Var : Bp->NewVariables)
{
    UE_LOG(LogTemp, Log, TEXT("Variable: %s"), *Var.VarName.ToString());
    for (auto& Item : Var.MetaDataArray)
    {
        UE_LOG(LogTemp, Log, TEXT("  - %s = %s"), *Item.DataKey.ToString(), *Item.DataValue);
    }
}

The metadata key for description is “tooltip”.

Note that the UBlueprint object is entirely stripped out of assets when cooking, so all this data is unavailable in shipping build.

[chepiok_pro (Chepiok)]

Not yet found how to move from a FProperty to the BP description if the property is not native (ie. BP variable). Stay tuned.

[Chatouille]

The Owner of the FProperty should be the UClass (UBlueprintGeneratedClass for blueprints).
Then you can go back to the blueprint via UClass->ClassGeneratedBy.
Then you’ll probably have to iterate that “NewVariables” array until you find a match by name.

Something like this :

// FProperty* Prop;
if (auto Class = Prop->GetOwner<UClass>())
{
    if (auto Bp = Cast<UBlueprint>(Class->ClassGeneratedBy))
    {
        for (auto& Var : Bp->NewVariables)
        {
            if (Var.VarName == Prop->GetFName())
                return Var.GetMetaData("tooltip");
        }
    }
}

[chepiok_pro (Chepiok)]

Works fine. Thanks.

[chepiok_pro (Chepiok)]

Damned. It works but only WITH_EDITOR, not in runtime.