deserialize based on value?

[amirotin]

Hi! I'm still playing with your amazing library. In continue of another question:

I've main dataclass:

@dataclass(slots=True)
class GameRequest(DataClassJSONMixin):
    c: int
    s: int
    d: Any
    o: str = None
    t: int = None

I've many other classes for different c value of main class and want to get them into d value. I tried to use field(metadata={"deserialize": ... }) and define custom _deserialize in SerializableType. But main problem is that i always get only dict, passed to d and i don't have any references to main class request.

using {'c': 1, 's': 2, 'o': 3, 't': 12345, 'd': {'zzz': 'aaa'}} i always get only {'zzz': 'aaa'}

[Fatal1ty]

Hi @amirotin

I read your message several times but I couldn't figure what problem you're facing. Can you give an example of what you did, what you got and what you expected?

[amirotin]

Ok :)

These are json examples

{'c': 1, 's': 11, 'o': 1, 't': 12345, 'd': {'qqq': 'some data'}}
{'c': 2, 's': 33, 'o': 2, 't': 12346, 'd': {'zzz': 'some data'}}
{'c': 3, 's': 33, 'o': 2, 't': 12347, 'd': {'xxx': 'some data'}}

I have main class

@dataclass(slots=True)
class GameRequest(DataClassJSONMixin):
    c: int
    s: int
    d: Any
    o: str = None
    t: int = None

I have request type classes

@dataclass(slots=True)
class Req1(DataClassJSONMixin):
    zzz: str


@dataclass(slots=True)
class Req2(DataClassJSONMixin):
    xxx: str

@dataclass(slots=True)
class Req3(DataClassJSONMixin):
    qqq: str

i want to get such result when i call GameRequest.from_json(json_request)

GameRequest(c=1, s=11, d=Req1(zzz='some data'), o=1, t=12345)
GameRequest(c=2, s=22, d=Req2(xxx='some data'), o=2, t=12346)
GameRequest(c=3, s=33, d=Req3(qqq='some data'), o=2, t=12347)

I've function which can return needed Req class for each value of c. deserialize options only gives me key d, but not the entire request dict d: Any = field(metadata={"deserialize": lambda v: get_req(v) })

[amirotin]

I also tried to make it working in this way:

@dataclass(slots=True)
class GameRequest(DataClassDictMixin, SerializableType):
    c: int
    s: int
    d: Any
    o: str = None
    t: int = None

    def _serialize(self):
        return self.to_dict()

    @classmethod
    def _deserialize(cls, value: Dict):
        print(value)
        if value.get("c") == 1:
            return Req1.from_dict(value.get('d'))
        elif value.get("c") == 2:
            return Req2.from_dict(value.get('d'))

but looks like _deserialize works only for class params, not for class itself. Or i made something wrong?

[Fatal1ty]

If the choice of the ReqX class depends on another field of GameRequest, you can use the post_deserialize hook:

@dataclass
class GameRequest(DataClassJSONMixin):
    c: int
    s: int
    d: Any
    o: str = None
    t: int = None

    @classmethod
    def __post_deserialize__(cls, obj):
        if obj.c == 1:
            obj.d = Req1.from_dict(obj.d)
        elif obj.c == 2:
            obj.d = Req2.from_dict(obj.d)
        elif obj.c == 3:
            obj.d = Req3.from_dict(obj.d)
        return obj

[amirotin]

post_deserialize would be last thing on my mind
Thanks! Worked.