json_decoding.elm

import Html.App exposing (beginnerProgram)
import Html.Events exposing (onClick)
import Date exposing (Date)
import Html exposing (..)
import Json.Decode as Js exposing ((:=))


main =
  beginnerProgram { model = 0, view = view, update = update }


view model =
  h1 [][text (toString f)]

f =
  Js.decodeString userDecoder """{"id":77, "name": "xxx"}"""

type Msg = Increment | Decrement


update msg model =
 model
 

type alias User = {id : Int, name : String}

-- Applicative's `pure`:
constructing : a -> Js.Decoder a
constructing = Js.succeed

-- Applicative's `<*>`:
apply : Js.Decoder (a -> b) -> Js.Decoder a -> Js.Decoder b
apply = Js.object2 (<|)

userDecoder : Js.Decoder User
userDecoder =
  constructing User
    `apply` ("id" := Js.int)
    `apply` ("name" := Js.string)
--    `apply` ("email" := Js.string)
--    `apply` ("created_at" := Js.customDecoder Js.string Date.fromString)