how to apply Decorator design pattern with rodi? #15
Description
Hi,
How to apply the Decorator design pattern with rodi, on single instance registrations and/or collection registrations?
Example how I used to do it with a DI container from C# .Net called SimpleInjector (if same syntax were to be in lagom):
class HttpClient(ABC):
async def send(self, request: Request) -> Response:
pass
class ActualHttpClient(HttpClient):
async def send(self, request: Request) -> Response:
# Implement actual request send, e.g. with aiohttp
class LoggingHttpClientDecorator(HttpClient):
def __init__(self, decoratee: HttpClient):
self.__decoratee = decoratee
async def send(self, request: Request) -> Response:
print("Sending request")
response = await self.__decoratee.send(request);
print("Received response")
return response;
container = Container()
container[HttpClient] = Singleton(ActualHttpClient)
container.RegisterSingletonDecorator[HttpClient, LoggingHttpClientDecorator](); # mimics the SimpleInjector syntax
With this code, resolving HttpClient would return LoggingHttpClientDecorator decorating ActualHttpClient.
SimpleInjector also supports collection injections, e.g. injecting something like Iterable[EventHandler], and apply a decorator to all of the EventHandler instances registered to the collection.