enum-struct

Enum and Struct Skill

Critical Rules

Read-Only Native Types

Native C++ enums and structs are read-only. Only UserDefinedEnums and UserDefinedStructs can be modified:

import unreal

# Search for user-defined enums only (editable)
enums = unreal.EnumStructService.search_enums("Weapon", True)  # bUserDefinedOnly=True

# Check if an enum is user-defined before modifying
# (returns a single EnumInfo or None — NOT a (success, info) tuple)
info = unreal.EnumStructService.get_enum_info("EMyEnum")
if info and info.is_user_defined:          # field is is_user_defined, NOT b_is_user_defined
    unreal.EnumStructService.add_enum_value("EMyEnum", "NewValue")

🚨 Pass the EXACT asset name you want — prefixing is dumb

create_enum / create_struct only prepend E/F when the name doesn't already start with that letter; they never insert underscores or reformat. So:

• want E_TestState → pass "E_TestState" (passing "TestState" creates ETestState)
• want EWeaponType → "WeaponType" or "EWeaponType" both work

Creation fails with an empty string if the asset already exists — delete it first (delete_enum / delete_struct), there is no overwrite.

🚨 Enum values: you are always working with DISPLAY names

UserDefinedEnum entries have immutable internal names (NewEnumerator0..N). Every EnumStructService method speaks display names: the name you pass to add_enum_value becomes the display name, get_enum_values returns display names, and rename_enum_value / remove_enum_value accept display names (rename changes the display name only). For internal+display pairs use get_enum_info(...).values (each entry has name = internal, display_name, value, index).

---

Workflows

Create UserDefinedEnum

import unreal

# Create a new enum — pass the exact final name (here E prefix gets prepended)
enum_path = unreal.EnumStructService.create_enum("/Game/Data/Enums", "WeaponType")
print(f"Created: {enum_path}")  # /Game/Data/Enums/EWeaponType.EWeaponType
if not enum_path:
    # creation failed — most likely the asset already exists; delete_enum first
    ...

# Add values
unreal.EnumStructService.add_enum_value(enum_path, "Sword", "Melee Sword")
unreal.EnumStructService.add_enum_value(enum_path, "Bow", "Ranged Bow")
unreal.EnumStructService.add_enum_value(enum_path, "Staff", "Magic Staff")

# Verify
values = unreal.EnumStructService.get_enum_values(enum_path)
print(f"Values: {values}")  # ['Sword', 'Bow', 'Staff']