feat(elm): Add initial logic for Gemma's Elm frontend

This commit is contained in:
Vincent Ambo 2017-12-19 18:26:26 +01:00
parent 95e4971908
commit 26f365271e
2 changed files with 117 additions and 0 deletions

101
frontend/Main.elm Normal file
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module Main exposing (..)
import Html exposing (Html, text, div, span)
import Json.Decode exposing (..)
import Http
-- API interface to Gemma
type alias Task =
{ name : String
, description : Maybe String
, remaining : Int
}
emptyStringFilter s =
if s == "" then
Nothing
else
Just s
decodeEmptyString : Decoder (Maybe String)
decodeEmptyString =
map emptyStringFilter string
decodeTask : Decoder Task
decodeTask =
map3 Task
(field "name" string)
(field "description" decodeEmptyString)
(field "remaining" int)
loadTasks : Cmd Msg
loadTasks =
let
request =
Http.get "http://localhost:4242/tasks" (list decodeTask)
in
Http.send NewTasks request
-- Elm architecture implementation
type Msg
= None
| LoadTasks
| NewTasks (Result Http.Error (List Task))
type alias Model =
{ tasks : List Task
, error : Maybe String
}
renderTask : Task -> Html Msg
renderTask task =
div [] [ span [] [ text task.name ] ]
view : Model -> Html Msg
view model =
div [] (List.map renderTask model.tasks)
update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
case msg of
LoadTasks ->
( model, loadTasks )
NewTasks (Ok tasks) ->
( { tasks = tasks, error = Nothing }, Cmd.none )
NewTasks (Err err) ->
( { model | error = Just (toString err) }, Cmd.none )
_ ->
( model, Cmd.none )
init : ( Model, Cmd Msg )
init =
( { tasks = [], error = Nothing }, loadTasks )
main : Program Never Model Msg
main =
Html.program
{ init = init
, view = view
, update = update
, subscriptions = always Sub.none
}

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frontend/elm-package.json Normal file
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{
"version": "1.0.0",
"summary": "helpful summary of your project, less than 80 characters",
"repository": "https://github.com/user/project.git",
"license": "BSD3",
"source-directories": [
"."
],
"exposed-modules": [],
"dependencies": {
"elm-lang/core": "5.1.1 <= v < 6.0.0",
"elm-lang/html": "2.0.0 <= v < 3.0.0",
"elm-lang/http": "1.0.0 <= v < 2.0.0"
},
"elm-version": "0.18.0 <= v < 0.19.0"
}