Elm 0.17 简单 Mouse.clicks 示例

Question

为了熟悉 0.17 中的 subscriptions，我试图让一个简单的应用程序运行，订阅 Mouse.clicks 并将 Model 递增一个。

目前该应用有以下投诉。

函数program期望参数为：

{ ...  
  , subscriptions : Float -> Sub Msg  
  , update : Msg -> Float -> ( Float, Cmd Msg )  
  , view : Float -> Html Msg   
}

但是是：

{ ...  
  , subscriptions : (Msg -> Position -> a) -> Sub a  
  , update : Msg -> number -> ( number, Cmd b )  
  , view : c -> Html d  
}

如有任何帮助，我们将不胜感激。

import Html exposing (Html, text, div)
import Html.App as Html
import Mouse exposing (..)

main =
  Html.program
    { init = init
    , view = view
    , update = update
    , subscriptions = subscriptions
    }

-- MODEL

type alias Model = Int

init : (Model, Cmd Msg)
init =
  (0, Cmd.none)

-- UPDATE

type Msg
  = Click

update msg model =
  case msg of
    Click ->
      (model + 1 , Cmd.none)

-- SUBSCRIPTIONS

subscriptions model =
  Mouse.clicks (model Click)

-- VIEW

view model =
  Html.text (toString model)

Answer 1

问题出在您的 subscriptions 函数中。您需要这样设置：

subscriptions model =
  Mouse.clicks (\_ -> Click)

Elm 0.17 简单 Mouse.clicks 示例

Elm 0.17 Simple Mouse.clicks example

elm