Elm 0.17-JSON数据不在视图中渲染

Question

我是Elm的新手，正在尝试计算0.17。我想知道是否有人知道为什么我的数据没有呈现在这里的视图中。在Chrome控制台中，我可以看到GET请求已成功发出，但它从未真正显示在页面上。我从URL返回的数据应该是这样的：

[{“title”：“Aut enim quia accusamus.”，“content”：“Ipsa aliquid disependedus laudantium velit。Voluptates corruption qui ut aut aut aut repudiandae。Ipsum molestiae ullam quasi molestiae qui quas。Error nobis cupiditate dolor molestiae officia qud doloribus。”，{“title”：“建筑师应承担的责任”，

module Questions exposing (..)

import List
import Html exposing (..)
import Html.App
import Html.Attributes exposing (..)
import Html.Events as Events
import Http
import Json.Decode as Json exposing ((:=))
import Task exposing (..)

main : Program Never
main =
  Html.App.program
    { init = init
    , update = update
    , view = view
    , subscriptions = \_ -> Sub.none }

--MODEL

type alias Question =
  { title : String
  , content : String }

type alias Model =
  { questions : List Question
  }

initialModel : Model
initialModel =
  { questions = []
  }

questionsDecoder : Json.Decoder (List Question)
questionsDecoder =
  Json.list questionDecoder

questionDecoder : Json.Decoder Question
questionDecoder =
  Json.object2
        Question
          ("title" := Json.string)
          ("content" := Json.string)

fetchData : Cmd Msg
fetchData =
  let
    url = "http://localhost:3000/api/questions"
  in
    Task.perform FetchFail FetchDone (Http.get questionsDecoder url)

--INIT

init : ( Model, Cmd Msg )
init =
  ( initialModel
  , fetchData )

--UPDATE

type Msg = NoOp
    | FetchData
    | FetchDone (List Question)
    | FetchFail Http.Error

update : Msg -> Model -> (Model, Cmd Msg)
update message model =
  case message of
    NoOp ->
      ( model, Cmd.none )
    FetchData ->
      ( model, fetchData)
    FetchDone results ->
      ( { model | questions = results }
      , Cmd.none )
    FetchFail error ->
      ( model, Cmd.none )

-- VIEW

questionView : Model -> Question -> Html Msg
questionView model question =
  div [ ]
    [ h3 [  ] [text question.title]
    , h5 [  ] [text question.content]
    ]

questionsListView : Model -> Html Msg
questionsListView model =
  ul [ ]
    (model.questions |> List.map (questionView model))

view : Model -> Html Msg
view model =
  div [ ]
    [ h1 [  ] [text "SLACK OVERFLOW"]
    , questionsListView initialModel
    ]

谢谢你的帮助！

Answer 1

在您的视图中，似乎总是传递初始模型：

view : Model -> Html Msg
view model =
  div [ ]
    [ h1 [  ] [text "SLACK OVERFLOW"]
    , questionsListView initialModel
    ]

我想您希望获得作为参数接收的模型：

view : Model -> Html Msg
view model =
    div [ ]
        [ h1 [  ] [text "SLACK OVERFLOW"]
        , questionsListView model
        ]