How can I define Enum fields for register_class() about oso HOT 3 CLOSED

# Models
import enum

from sqlalchemy import Boolean, Column, Enum, ForeignKey, Integer, MetaData, create_engine
from sqlalchemy.orm import declarative_base, relationship, sessionmaker


BaseModel = declarative_base(metadata=MetaData())


class ArticleType(enum.Enum):
    NEWS = "News"
    RECIPE = "Recipe"
    BLOG = "Blog"


class Action(enum.Enum):
    READ = "Read"
    WRITE = "Write"


class UserPermission(BaseModel):
    __tablename__ = "user_permission"
    id = Column(Integer, primary_key=True)
    article_type = Column(Enum(ArticleType), nullable=False)
    action = Column(Enum(Action), nullable=False)
    access = Column(Boolean(), nullable=False)
    user_id = Column(
        Integer, ForeignKey("user.id", ondelete="CASCADE"), index=True, nullable=False
    )


class User(BaseModel):
    __tablename__ = "user"
    id = Column(Integer, primary_key=True)
    permissions = relationship(
        UserPermission, single_parent=True, cascade="all, delete-orphan"
    )


class Article(BaseModel):
    __tablename__ = "article"
    id = Column(Integer, primary_key=True)
    type = Column(Enum(ArticleType))


# Create some data
engine = create_engine("sqlite://", isolation_level=None)
BaseModel.metadata.create_all(engine)

factory = sessionmaker(bind=engine, autocommit=False)
session = factory()


reader = User(
    permissions=[
        UserPermission(article_type=ArticleType.NEWS, action=Action.READ, access=1),
        UserPermission(article_type=ArticleType.RECIPE, action=Action.READ, access=1),
        UserPermission(article_type=ArticleType.NEWS, action=Action.WRITE, access=0),
        UserPermission(article_type=ArticleType.RECIPE, action=Action.WRITE, access=0),
    ]
)
writer = User(
    permissions=[
        UserPermission(article_type=ArticleType.NEWS, action=Action.READ, access=1),
        UserPermission(article_type=ArticleType.RECIPE, action=Action.READ, access=1),
        UserPermission(article_type=ArticleType.NEWS, action=Action.WRITE, access=1),
        UserPermission(article_type=ArticleType.RECIPE, action=Action.WRITE, access=1),
    ]
)

news = Article(type=ArticleType.NEWS)

session.add(reader)
session.add(writer)
session.add(news)
session.commit()


# OSO auth
from oso import NotFoundError, Oso


oso = Oso()
oso.register_class(Article)
oso.register_class(User)
oso.load_str(
    """
allow(actor, action, resource) if
  has_permission(actor, action, resource);

has_permission(user: User, action: String, article: Article) if
  perm in user.permissions and
  perm.article_type = article.type and
  perm.action.value = action and
  perm.access;


resource Article {
  permissions = ["Read", "Write", "Approve"];
}

actor User {}

"""
)

oso.authorize(reader, "Read", news)
print("Viewer can read news")
oso.authorize(writer, "Read", news)
print("Writer can read news")

try:
    oso.authorize(reader, "Write", news)
except NotFoundError:
    print("Viewer cannot write news")

oso.authorize(writer, "Write", news)
print("Writer can write news")

# OSO query
from polar.data.adapter.sqlalchemy_adapter import SqlAlchemyAdapter

oso.set_data_filtering_adapter(SqlAlchemyAdapter(session))

oso.authorized_resources(reader, 'Read', Article)