expectStringResponseExample.elm

import Http
import Json.Decode as D

expectJson : (Result Http.Error a -> msg) -> D.Decoder a -> Expect msg
expectJson toMsg decoder =
  expectStringResponse toMsg <|
    \response ->
      case response of
        Http.BadUrl_ url ->
          Err (Http.BadUrl url)

        Http.Timeout_ ->
          Err Http.Timeout

        Http.NetworkError_ ->
          Err Http.NetworkError

        Http.BadStatus_ metadata body ->
          Err (Http.BadStatus metadata.statusCode)

        Http.GoodStatus_ metadata body ->
          case D.decodeString decoder body of
            Ok value ->
              Ok value

            Err err ->
              Err (Http.BadBody (D.errorToString err))