Http DELETE with empty body - http

Question

In Elm (0.18) I'm calling one http DELETE endpoint that if successful responds with 200 and an empty body.
In this case (of success) I need to pass back a message with the initial id (OnDelete playerId). But as the body is empty i can't parse it from there.
Currently I'm doing it like this, but is there a more elegant way to write the expect part of Http.Request:
Http.expectStringResponse (\response -> Ok playerId)
?
This reflects my current code:
deletePlayer : PlayerId -> Cmd Msg
deletePlayer playerId =
deleteRequest playerId
|> Http.send OnDelete
deleteRequest : PlayerId -> Http.Request PlayerId
deleteRequest playerId =
Http.request
{ body = Http.emptyBody
, expect = Http.expectStringResponse (\response -> Ok playerId)
, headers = []
, method = "DELETE"
, timeout = Nothing
, url = "http://someHost/players/" ++ playerId
, withCredentials = False
}
type alias PlayerId =
String

Answer 1

Elm v0.19 added expectWhatever. It behaves slightly different with the Result being checked for errors, but a similar effect.
I've created a helper expectUnit for "empty" 200 responses.
expectUnit : Expect ()
expectUnit =
Http.expectStringResponse << always <| Ok ()
deleteThing : String -> Request ()
deleteThing path =
Http.request
{ method = "DELETE"
, headers = []
, url = "http://localhost/api"
, body = Http.jsonBody <| Encode.object [ ( "path", Encode.string path ) ]
, expect = expectUnit
, timeout = Nothing
, withCredentials = False
}
But for you, the best you could get is.
{ ...
, expect = Http.expectStringResponse << always <| Ok playerId
...
}
Or you could create a helper (which is actually the singleton or pure for Expect)
alwaysExpect : a -> Expect a
alwaysExpect =
Http.expectStringResponse << always << Ok
Which could be used like
{ ...
, expect = alwaysExpect playerId
...
}