haskell-servant/servant

Dynamic Content Type

Open

#501 opened on May 7, 2016

View on GitHub
 (14 comments) (1 reaction) (0 assignees)Haskell (1,953 stars) (422 forks)batch import
enhancementhelp wantedrfcservant-client

Description

The library is great! But there is one thing that I've been trying to figure out how to do: setting a content type on servant client depending on the input. How do I let the user define the content type? When I create the client routes, the content type is always defined next to ReqBody. Is there any way to do that?

A use case is file upload. For example, an avatar could have many different mime type values.

Contributor guide

Tech stack
None
Domain
api
Issue type
feature
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
4
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
over 1 week
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
needs investigation
Prerequisites
Haskell basicsservant librarytype level programming
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
20
Research direction
The issue asks how to implement dynamic content types in servant client. It references the ReqBody type. The solution would likely involve modifying the servant client library to accept a runtime content type parameter. Relevant files include Servant.Client.Core.HasClient and Servant.API.ContentTypes. The discussion in the issue may contain further ideas. A first step would be to understand the current type level encoding of content types and then design a way to make it dynamic.