I have a client with `ContentNegotiation` / `json`...

# ktor

[rocketraman]

I have a client with ContentNegotiation / json installed. I want one particular request to return application/pdf. I've specified accept(ContentType.Application.Pdf).withParameter("q", "2.0") to try and get the server to return PDF instead, but it doesn't work -- seems the Spring server doesn't like a quality value > 1.

It seems like the automatic ContentNegotation Accept header should add application/json with a lower quality value so that the user can override it on a per-request basis.

Is there a workaround to this?

[Olivier Patry]

Can't you use

contentType(ContentType.Application.Pdf)

in the request?

I use this for instance

val response = <http://httpClient.post|httpClient.post>("...") {
    contentType(ContentType.Application.Json)
    setBody(obj)
}

[rocketraman]

ContentType tells the server what the client is sending. I'm talking about the Accept header which tells the server what we want to receive in the response.

[rocketraman]

I created this KTOR issue / feature request, and also detailed a workaround in there that uses a custom plugin -- https://youtrack.jetbrains.com/issue/KTOR-7722/ContentNegotiation-client-plugin-no-way-to-opt-out-of-Accept-on-a-per-request-basis.

[Chrimaeon]

I guess the right approach would be to create and register a content negotiation plugin that can handle application/pdf. so when making the request, Ktor can handle the response and will set the header correctly if you specify it.

[rocketraman]

It won't solve the problem on its own. The new PDF registration for the ContentNegotiation plugin will simply result in both types added into the Accept header, which is exactly what already happens by specifying accept(ContentType.Application.Pdf) in the RequestBuilder.

[Chrimaeon]

did you try it or is that an assumption?

[rocketraman]

Its an assumption based on the code.