Migration from dataclass_rest

Basic usage

1. Replace imports

# dataclass-rest
from dataclass_rest.http.requests import RequestsClient
from dataclass_rest.http.aiohttp import AiohttpClient

# descanso
from descanso.http.requests import RequestsClient
from descanso.http.aiohttp import AiohttpClient

2. Create RestBuilder for access to decorators.

# dataclass-rest
from dataclass_rest import get

class Client(RequestsClient):
    @get("/")
    def get_x(self) -> Model: ...

# descanso
from descanso import RestBuilder

rest = RestBuilder()

class Client(RequestsClient):
    @rest.get("/")
    def get_x(self) -> Model: ...

3. Move factories from Client methods to RestBuilder. As they are not reused across different purposes by default anymore.

# dataclass-rest
class RealClient(RequestsClient):
    def _init_request_body_factory(self) -> Retort:
        return Retort(recipe=[
            name_mapping(name_style=NameStyle.CAMEL),
        ])

# descanso
retort = Retort(
    recipe=[
        name_mapping(name_style=NameStyle.CAMEL),
    ]
)
rest = RestBuilder(
    request_body_dumper=retort,
    response_body_loader=retort,
    query_param_dumper=retort,
)

4. If you we changing query parameter name using Retort, map it manually. You can do it per method or on the RestBuilder.

# dataclass-rest
class RealClient(RequestsClient):
    def _init_request_args_factory(self) -> Retort:
        return Retort(recipe=[
            name_mapping(name_style=NameStyle.CAMEL),
        ])

    @get("/")
    def get_all(self, per_page: int) -> list[Model]: ...


# descanso
from descanso.request_transformers import Query

class RealClient(RequestsClient):
    @rest.get("/", Query("perPage", "{per_page}"))
    def get_all(self, per_page: int) -> list[Model]: ...

5. Replace body_name with Body(). You can do it per method or on the RestBuilder.

# dataclass-rest
class RealClient(RequestsClient):
    @post("/", body_name="data")
    def get_all(self, data: Mode) -> None: ...

# descanso
from descanso.request_transformers import Body

class RealClient(RequestsClient):
    @post("/", Body("data"))
    def get_all(self, data: Mode) -> None: ...

6. Replace send_json=False with request_body_post_dump=None. You can do it per method or on the RestBuilder.

# dataclass-rest
class RealClient(RequestsClient):
    @post("/", send_json=False)
    def get_all(self, body: str) -> None: ...

# descanso
from descanso.transformers.request import Body

class RealClient(RequestsClient):
    @post("/", request_body_post_dump=None)
    def get_all(self, body: str) -> None: ...

Custom client and method classes

In dataclass_rest part of request processing was done in Client class while another one is located in BoundMethod. In descanso you have 2 main things:

1. Client contains send_request or asend_request method. They send request and return SyncResponseWrapper/AsyncResponseWrapper instance

2. Response Wrapper is an extension to HttpResponse which allows you to load body during response processing.

Earlier you had several reasons to override methods

1. Authorization. See Authorization

2. Handling 204. In descanso body is automatically skipped for responses with codes other than 200, 201, 202. You can change it setting response_body_pre_load=JsonLoad(codes=(200, 201, 203, 204))

3. Retrieving body for errors. Set error_raiser=ErrorRaiser(need_body=True)

Handling 4xx and 5xx

There is no more on_error helper in descanso. Instead you can set error_raiser which is executed before any other ResponseTransformer. You can use ErrorRaiser() customizing expected codes which are treated as errors or create own transformer.