Bi-directional variable (inverse relation shadow variable) won’t work in python because of object comparison

[binarymind]

Hello,
I have a problem : I am in python and try to code the equivalent of :

@planning_entity
class Lesson:
    timeslot: Annotated['Timeslot', PlanningVariable]
    ...

and

@planning_entity
class Timeslot:
    lesson_list: Annotated[list[Lesson], InverseRelationShadowVariable(source_variable_name ="timeslot")]
    ...

1 - I can’t find any snippet with the full working code of this : a real planningVariable and a list of the shadowVariable

something with the full code of the doc

2 - my problem is that when timefold add the entity in the shadow variable after the allocation it can’t detect it and tell me :

here is my domain.py

@planning_entity
class Barrette(JsonDomainBase):
    id: Annotated[str, PlanningId]
    name:str
    eleves: Annotated[
        list["Eleve"], 
        InverseRelationShadowVariable(source_variable_name ="barrette"),
        IdListSerializer, 
        EleveListValidator,
        Field(default_factory=list)
    ]
    
@planning_entity
class Eleve(JsonDomainBase):
    id: Annotated[str, PlanningId]
    name: str
    barrette: Annotated[Optional[Barrette],
                        PlanningVariable,
                        IdSerializer,
                        BarretteValidator,
                        Field(default=None)]
    
@planning_solution
class Timetable(JsonDomainBase):
    id: str
    barrettes: Annotated[list[Barrette],
                         PlanningEntityCollectionProperty,
                         ValueRangeProvider]
    eleves: Annotated[list[Eleve],
                     PlanningEntityCollectionProperty]
    score: Annotated[HardSoftScore | None,
                     PlanningScore,
                     ScoreSerializer,
                     ScoreValidator,
                     Field(default=None)]
    solver_status: Annotated[SolverStatus, Field(default=SolverStatus.NOT_SOLVING)]

here is json_serialization.py :

def make_id_item_validator(key: str):
    def validator(v: Any, info: ValidationInfo) -> Any:
        if v is None:
            return None

        if not isinstance(v, str) or not info.context:
            return v
        return info.context.get(key)[v]

    return BeforeValidator(validator)


def make_id_list_item_validator(key: str):
    def validator(v: Any, info: ValidationInfo) -> Any:
        if v is None:
            return None
        if isinstance(v, (list, tuple)):
            out = []
            for item in v:
                if not isinstance(v, str) or not info.context:
                    return v
                out.append(info.context.get(key)[item])
            return out

        return v

    return BeforeValidator(validator)


BarretteValidator = make_id_item_validator('barrettes')
EleveListValidator = make_id_list_item_validator('eleves')

IdSerializer = PlainSerializer(lambda item: item.id if item is not None else None,
                               return_type=str | None)
IdListSerializer = PlainSerializer(lambda items: [item.id if item is not None else None for item in items], return_type=list)

generate the error

java.lang.IllegalStateException: The entity (id='2' name='e' barrette=Barrette(id='1', name='b', eleves=[Eleve(id='2', name='e', barrette=Barrette(id='1', name='b', eleves=[...]))])) has a variable (barrette) with value (id='1' name='b' eleves=[Eleve(id='2', name='e', barrette=Barrette(id='1', name='b', eleves=[...]))]) which has a sourceVariableName variable (eleves) with a value ([Eleve(id='2', name='e', barrette=Barrette(id='1', name='b', eleves=[Eleve(id='2', name='e', barrette=Barrette(id='1', name='b', eleves=[...]))]))]) which did not contain the entity (id='2' name='e' barrette=Barrette(id='1', name='b', eleves=[Eleve(id='2', name='e', barrette=Barrette(id='1', name='b', eleves=[...]))])).
Verify the consistency of your input problem for that bi-directional relationship.

3 - if I try to add eq function in the entities it tells me

java.lang.NullPointerException: java.lang.NullPointerException: Cannot invoke "org.jpyinterpreter.synthetic.signature.InterfaceSignature$$610.invoke(org.jpyinterpreter.user.src.barrettes.domain.Eleve, ai.timefold.jpyinterpreter.PythonLikeObject)" because "org.jpyinterpreter.user.src.barrettes.domain.Eleve.$methodholder$__eq__" is null

If someone have any lead to help me that would be awesome
cheers

[Christopher-Chianelli]

I think there is a bug here, but oddly enough, the bug is only triggered when the class with InverseRelationShadowVariable is defined before the entity class it references.

I think the following code will work:

@planning_entity
class Eleve(JsonDomainBase):
    id: Annotated[str, PlanningId]
    name: str
    barrette: Annotated[Optional["Barrette"],
                        PlanningVariable,
                        IdSerializer,
                        BarretteValidator,
                        Field(default=None)]
    
    def __eq__(self, o):
        return self.id == o.id
    
    def __hash__(self):
        return hash(self.id)


@planning_entity
class Barrette(JsonDomainBase):
    id: Annotated[str, PlanningId]
    name:str
    eleves: Annotated[
        list[Eleve], 
        InverseRelationShadowVariable(source_variable_name ="barrette"),
        IdListSerializer, 
        EleveListValidator,
        Field(default_factory=list)
    ]

    
@planning_solution
class Timetable(JsonDomainBase):
    id: str
    barrettes: Annotated[list[Barrette],
                         PlanningEntityCollectionProperty,
                         ValueRangeProvider]
    eleves: Annotated[list[Eleve],
                     PlanningEntityCollectionProperty]
    score: Annotated[HardSoftScore | None,
                     PlanningScore,
                     ScoreSerializer,
                     ScoreValidator,
                     Field(default=None)]
    solver_status: Annotated[SolverStatus, Field(default=SolverStatus.NOT_SOLVING)]

[binarymind]

OMG it indeed seems to work !!!! thanks mate you saved me