通过 elm 发送 graphql 突变

Question

我正在尝试让我的 elm (v: 0.18) 客户端通过 graphql 与我的后端对话。我现在正在尝试避免使用 elm-graphql 库和基本的 elm HttpBuilder 模块。

登录命令如下所示：

loginCmd : Model -> Cmd Msg
loginCmd model =
    let
        graphiql =
            """
              mutation {
                login(email: "me@myapp.com", password: "password") {
                  token
                }
              }
            """
    in
        HttpBuilder.post ("http://localhost:4000/api")
            |> HttpBuilder.withStringBody graphiql
            |> HttpBuilder.withExpect (Http.expectJson myJsonDecoder)
            |> HttpBuilder.send GetTokenCompleted

问题出在withStringBody函数上。编译器发送给我：

The right side of (|>) is causing a type mismatch.

101|         HttpBuilder.post ("http://localhost:4000/api")
102|>            |> HttpBuilder.withStringBody graphiql

(|>) is expecting the right side to be a:

    RequestBuilder () -> a

But the right side is:

    String -> RequestBuilder a -> RequestBuilder a

我不确定问题是什么，鉴于 HttpBuilder docs 说它是 withStringBody : String -> RequestBuilder -> RequestBuilder 类型，并以此为例：

post "https://example.com/api/items/1"
  |> withHeader "Content-Type" "application/json"
  |> withStringBody """{ "sortBy": "coolness", "take": 10 }"""

我做错了什么？

Answer 1

根据文档，withStringBody 实际上需要 String -> String -> RequestBuilder a，所以我会说您需要在 graphql 字符串之前添加一个内容字符串，无论什么适合您的 graphql后端。

|> HttpBuilder.withStringBody "text/plain" """{ "sortBy": "coolness", "take": 10 }"""

通过 elm 发送 graphql 突变

Sending graphql mutations through elm

elm

graphql