带有空主体的 Http DELETE

Question

在 Elm (0.18) 中，我正在调用一个 http DELETE 端点，如果成功，它会以 200 和一个空主体响应。

在这种情况下(成功)我需要传回一 strip 有初始 ID (OnDelete playerId) 的消息。但由于 body 是空的，我无法从那里解析它。

目前我是这样做的，但是有没有更优雅的方式来编写 Http.Request 的 expect 部分:

Http.expectStringResponse (\response -> Ok playerId)

?

这反射(reflect)了我当前的代码:

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

添加了 Elm v0.19 expectWhatever .它的行为与检查错误的 Result 略有不同，但效果相似。

---

我为“空”200 响应创建了一个助手 expectUnit。

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
        }

但对你来说，你能得到的最好的是。

{ ...
, expect = Http.expectStringResponse << always <| Ok playerId
...
}

或者您可以创建一个助手(实际上是 Expect 的 singleton 或 pure)

alwaysExpect : a -> Expect a
alwaysExpect =
     Http.expectStringResponse << always << Ok

可以像这样使用

{ ...
, expect = alwaysExpect playerId
...
}