Hi, I was looking at
BuiltInErrors for a possible extension of the algebra and noticed that while the algebra is content type independent, the various interpreters always implement its methods with the application/json content type. My thought then was: wouldn't it be better to use jsonResponse from JsonEntities for this to prevent repeating this pattern? It occurred to me that the reason might be because you then had to mix in JsonEntities in BuiltInErrors and the latter is used in all the Endpoints interpreters it would enforce a possibly unwanted dependency on the user. Is that correct or is there some other reason?
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Sorry for asking all these questions, but I have another one (please tell me if I need to stop :see_no_evil:). Did you at one time consider to add support for redirect endpoints? Currently, I need to explicitly add any redirect url to the server implementation. This feels somewhat awkward and of course the documentation or client support is left out. On the other hand, I can imagine that it's kind of a niche use case. When would you want to document redirects with OpenAPI, or support it in a client? In my case I have a server that is both a JSON API and an HTML staticfile server, of which the latter has redirects. For simplicity and clarity I'd like to define both with endpoints4s. I guess that's kind of a use case, be it a niche one. Another use case I can think of is API endpoints redirecting trailing slashes to no trailing slashes (e.g.
/api/v1/users/ to /api/v1/users) or vice-versa. This is often done with APIs to make the endpoints more discoverable (not fail on a single slash). Both use cases can be implemented in pure server code of course, but I think it would be cool to use the clean interface of endpoints4s for this if possible. What do you think?
22 replies
but isn't it an issue of the algebra because
handleClientErrors only gets an instance of Invalid ?
But I agree that it seems impossible to know the route that failed from there
(ftr, the equivalent method in the akka-http interpreter does provide a way to retrieve the underlying route)
So, in the case of the http4s server, I agree that we should change the signature of
handleClientErrors to receive more information about the underlying request
that being Java 15.0.1 do we need that flag?
endpoints4s/endpoints4s#755 done. yeah i threw out the VM arg. I think it's a common flag for SBT speedup but it works just fine without it.
The way i did that right now is by having an intermediate trait with
protected def authenticatedRequest[UrlP, BodyP, Out](
method: Method,
url: Url[UrlP],
entity: RequestEntity[BodyP]
)(implicit
tuplerUB: Tupler.Aux[UrlP, BodyP, Out]
): Request[ApiEndpoints.AuthenticatedMessage[Out]]and that works fine for requests. but one of the issues of response logging is that the process of encoding a response is not effectful
I am even considering operating on the algebra itself and changing the way the
implementedByEffect works to accomodate this
So, I think the only way to go is to do like you did. Define your own methods that wrap the existing algebra, and that do their side-effects. But this might need some changes in how the http4s interpreter is defined, since not all types can be interpreter with effectful computations, as you noticed…
maybe a new abstract type member that captures the effect on encoding?
then what I want would be much easier, overwrite that, add effectful logging and i should be done. might need some annoying machinery though to make this work though
Don't know if this is related, but are there ways in the current algebra to compose different endpoints? For example, we have multiple endpoints that add functionality to an endpoint, such as
One way we thought of is to instantiate and Endpoint to a class like
authenticatedEndpoint[A, B]: Endpoint[A, Either[AuthError], B], endpointWithError[A, B]: Endpoint[A, Either[ClientError, B]] and versionedEndpoint[A, B](version: ApiVersion): Endpoint[A, B]. Because the Endpoint type is abstract, I cannot find a way to compose these like (pseudo-code): authenticateEndpoint(endpointWithError(versionedEndpoint(...))).One way we thought of is to instantiate and Endpoint to a class like
Endpoints(request: A, response: B, url: String,...) and then "rewrite" these in the interpreters to the corresponding instances (e.g. Route for Akka HTTP server or A => Future[B] for client). But I have a feeling this would involve a pretty fundamental change to the algebras so I'm certainly open to other ideas.
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What is exactly the use of
def uri in the Akka HTTP interpreter? It doesn't seem to be used in any code, except via-via in a single line in one test. Could it be possible that the function is not needed? https://github.com/endpoints4s/endpoints4s/blob/master/akka-http/server/src/main/scala/endpoints4s/akkahttp/server/Endpoints.scala#L50
5 replies
@ptrdom Hello, you’re right
ChunkedEntities is not supported by endpoints.xhr. I don’t remember why I didn’t include it, to be honest. I also remember that I created #287 when I was working on it, so maybe I faced some limitations when trying to implement ChunkedEntities in the xhr interpreter.
@julienrf Thank you for the reply. I am really interested in having a capability of bidirectional streaming in API.
grpc-web should eventually support this, but there is no clear timeline for client-side streaming support, and protobuf model does seem unnecessarily limiting for traditional web API, compared to JSON. It would be an interesting endeavor to implement endpoints4s/endpoints4s#287, maybe I could give it a shot.
@ptrdom That would be a great contribution, although it might require some significant work! By the way, I’ve just found this old attempt at implementing an xhr interpreter for streaming: https://github.com/endpoints4s/endpoints4s/compare/streaming-support#diff-fe8014ca568bf3fc852541330ae13649cf8d4e298abea4ce777f73ddeabd33e2.
I don’t fully remember if eventually I didn’t include it in my final work on streaming because it was not working, or because I didn’t have the resources to finalize the implementations
See also the PR that introduced streaming support, where I give some implementation details: endpoints4s/endpoints4s#465