]jbdZddlmZddlmZddlmZddlmZGddejZ y) a FSM Serializer Fields for Django Rest Framework. Provides reusable DRF serializer fields for exposing FSM state in API responses. These fields work seamlessly with the FSMStateQuerySetMixin annotations to prevent N+1 queries. Usage: from fsm.serializer_fields import FSMStateField class TaskSerializer(serializers.ModelSerializer): state = FSMStateField(read_only=True) class Meta: model = Task fields = ['id', 'data', 'state', ...] Note: All state serialization functionality is guarded by TWO feature flags: 1. 'fflag_feat_fit_568_finite_state_management' - Controls FSM background calculations 2. 'fflag_feat_fit_710_fsm_state_fields' - Controls state field display in APIs When either flag is disabled, fields return None. This allows enabling FSM background work while keeping state fields hidden during incremental rollout and testing. )CurrentContext)flag_set) StateManager) serializersc.eZdZdZfdZdZdZxZS) FSMStateFielda Read-only DRF field for exposing FSM state. This field automatically uses the `state` or `current_state` annotation if present (preventing N+1 queries), or falls back to querying the state manager if the annotation is missing. Key features: - Works with annotated querysets (no N+1 queries) - Falls back to StateManager for single object retrievals - Always read-only (state changes through transitions only) - Returns None if FSM is disabled or no state exists Example with annotations (optimal): # In your viewset def get_queryset(self): return Task.objects.all().with_state() # In your serializer class TaskSerializer(serializers.ModelSerializer): state = FSMStateField() class Meta: model = Task fields = ['id', 'data', 'state'] # Result: No N+1 queries, state comes from annotation Example without annotations (fallback): # Direct object retrieval task = Task.objects.get(id=123) serializer = TaskSerializer(task) # Result: Calls StateManager.get_current_state_value() # Still efficient due to StateManager caching c H|jddt|di|y)Nsource*) setdefaultsuper__init__)selfkwargs __class__s L/root/env/lib/python3.12/site-packages/label_studio/fsm/serializer_fields.pyrzFSMStateField.__init__Gs% (C( "6"ctj}td|r td|sy|yt|dr |jSt|dr |j S t j|S#t$rYywxYw)z Serialize the FSM state to a string. Args: instance: The model instance being serialized Returns: str or None: The current state value (None if either feature flag disabled) *fflag_feat_fit_568_finite_state_management)user#fflag_feat_fit_710_fsm_state_fieldsNstate current_state) rget_userrhasattrrrrget_current_state_value Exception)rinstancers rto_representationzFSMStateField.to_representationMs&&( A M>TJ   8W %>> ! X /)) )  77A A  s$A99 BBctd)zJ This field is read-only, so this should never be called. zr/s.40'*&YbK--Ybr