Hi all, how can I create a client plugin/interceptor that reads the response with `bodyAsText` witho...

# ktor

[borisdamato]

Hi all, how can I create a client plugin/interceptor that reads the response with bodyAsText without interfering with other plugins that might want to do the same? At the moment I see that the body can only be read once, after which it gets consumed. Is there a way to prevent that? Thanks

[CLOVIS]

I believe this is what you want: https://ktor.io/docs/double-receive.html

[borisdamato]

Is this applicable to Ktor client too?

[borisdamato]

I'm already using call.save() following the implementation in ktor's default RequestValidator, I think that should have a similar effect, as it reads the body and copies it in a SavedHttpCall , which also sets allowDoubleReceive: Boolean = true on the call itself, but I'm still unable to read the body twice

[borisdamato]

my understanding is that SavedHttpResponse creates a new ByteReadChannel based on the saved body every time response.content is called, but it doesn't seem to be working for me. When I try to read bodyAsText again, I get a CancellationException saying that the parent job was completed

[borisdamato]

the response coroutineContext's job is completed as soon as the body is read and I can't find a way to prevent that

[borisdamato]

Unless I'm missing something I'm starting to think there's something wrong in the api, the finally block for bodyNullable always completes the response coroutine job, and there's no other way to access the saved responseBody in the SavedHttpCall because getResponseContent is protected and that's the only one creating a new ByteReadChannel with the saved content

[Aleksei Tirman [JB]]

Can you describe what problem is to be solved by the interceptor/plugin?

[borisdamato]

@Aleksei Tirman [JB] The usecase is the combination of 2 interceptors handling failure responses:
1. The first one is ready the body via bodyAsText() and logging it to our backend logging service
2. The second one is my version of the HttpResponseValidator where I convert the response into my internal exception which contains the deserialized error (via body<MyError>() + the raw response body via bodyAsText()).
For instance, for interceptor no.2, reading the body via bodyAsText() makes the following body<MyError>() throw the cancelled exception even if I transformed my call in a SavedHttpCall by calling save() in advance, and I assume that's because bodyNullable() completes the job even for SavedHttpResponse

[borisdamato]

From what I understand, being able to do something like that appears to be the point of SavedHttpCall, and I can see that it overrides getResponseContent() by always creating a new ByteReadChannel with the saved response content for that purpose, but then the fact that executing bodyNullable always completes the scope's job defeats its purpose.

[borisdamato]

And from what I can see using bodyNullable is the only way I can access the saved response content (because of the getResponseContent), as the other APIs are not public

[Aleksei Tirman [JB]]

Calling the body method in a HttpResponseValidator consumes a response body as described in KTOR-4225.

[borisdamato]

Thanks, good to know it's being worked on, I'm not using HttpResponseValidator directly, but I think this still applies in my case as I'm following a similar implementation