Automatically adding category sections to editor

YourProjectEditorModule.cpp

// add this code to your StartupModule() function of your EDITOR module
// if it doesnt work, try setting loading phase to "postdefault" -- no idea if this will produce side effects though.
// basically idea is looping all CDOs (i.e. UClasses) and their properties, getting their "category" meta value and registering them to
// property sections

FPropertyEditorModule& PropertyModule = FModuleManager::LoadModuleChecked<FPropertyEditorModule>("PropertyEditor");

static constexpr bool bAddSubcategories = false; // you probably want this to be false

auto ProcessCategory = [&PropertyModule](const FName ClassName, const FString& Category)
{
	const TSharedRef<FPropertySection> Section = PropertyModule.FindOrCreateSection(ClassName, *Category, FText::FromString(Category));
	if (!Section->HasAddedCategory(*Category))
	{
		Section->AddCategory(*Category);
	}
};

auto IsValidCategory = [](const FString& Category)
{
	return !Category.IsEmpty() && Category != TEXT("None");
};

auto IsPropertyAllowed = [](const FProperty* Property)
{
	return Property->HasAnyPropertyFlags(CPF_BlueprintVisible | CPF_Edit);
};

for (TObjectIterator<UClass> ClassIterator; ClassIterator; ++ClassIterator)
{
	const UClass* Class = *ClassIterator;
	if (Class->HasAnyClassFlags(CLASS_Abstract | CLASS_Deprecated | CLASS_NewerVersionExists))
	{
		continue;
	}
	for (const FProperty* Property = Class->PropertyLink; Property != nullptr; Property = Property->PropertyLinkNext)
	{
		if (IsPropertyAllowed(Property))
		{
			// prepare values
			const FName ClassName = Property->GetOwnerUObject()->GetFName();
			const FString CategoryString = Property->GetMetaData("Category");
			if (!IsValidCategory(CategoryString)) // skip empty categories
			{
				continue;
			}
			// if we have sub categories, parse it into array and add them individually
			TArray<FString> Subcategories;
			if (CategoryString.ParseIntoArray(Subcategories, TEXT("|")) > 0)
			{
				if (bAddSubcategories)
				{
					for (const FString& Subcategory : Subcategories)
					{
						if (IsValidCategory(Subcategory))
						{
							ProcessCategory(ClassName, Subcategory);
						}
					}
				}
				else
				{
					FString Subcategory = Subcategories[0]; // just use first subcategory
					if (IsValidCategory(Subcategory))
					{
						ProcessCategory(ClassName, Subcategory);
					}
				}
			}
			else // otherwise just process single category
			{
				ProcessCategory(ClassName, CategoryString);
			}
		}
	}
}