/Main.elm

## elm-package.json
{
    "version": "1.0.0",
    "summary": "Tell the world about your project!",
    "repository": "https://github.com/user/project.git",
    "license": "BSD3",
    "source-directories": [
        "."
    ],
    "exposed-modules": [],
    "dependencies": {
        "elm-lang/core": "5.1.1 <= v < 5.1.1",
        "elm-lang/html": "2.0.0 <= v < 2.0.0",
        "NoRedInk/elm-decode-pipeline": "3.0.0 <= v < 3.0.0"
    },
    "elm-version": "0.18.0 <= v < 0.19.0"
}

## index.html
<html>
<head>
  <style>
    html {
      background: #F7F7F7;
      color: red;
    }
  </style>
</head>
<body>
  <script>
    var app = Elm.Main.fullscreen()
  </script>
</body>
</html>

## Main.elm
module Main exposing (..)

import Html exposing (Html, div, li, text, ul)
import Json.Decode as Json exposing (Decoder, andThen, at, fail, int, list, map, nullable, string, succeed)
import Json.Decode.Pipeline exposing (custom, decode, hardcoded, optional, required)
import String exposing (join)


main : Html a
main =
    div []
        [ div [] [ text <| "Showing contacts for language " ++ toString model.language ]
        , viewContacts model.language model.contacts
        ]


type Language
    = Arabic
    | Hebrew


type Name
    = Name Language String


type alias Contact =
    { name : List Name
    , phone : String
    }


contact1 : Contact
contact1 =
    { name =
        [ Name Arabic "Foo"
        , Name Hebrew "Bar"
        ]
    , phone = "1234"
    }


contact2 : Contact
contact2 =
    { name =
        [ Name Hebrew "Nik"
        ]
    , phone = "5678"
    }


type alias Model =
    { language : Language
    , contacts : List Contact
    }


model : Model
model =
    { language = Hebrew
    , contacts = [ contact1, contact2 ]
    }


viewContacts : Language -> List Contact -> Html msg
viewContacts language contacts =
    div []
        (List.map
            (\contact ->
                ul
                    []
                    [ li [] [ text <| getContactNameByLanguage language contact ]
                    , li [] [ text contact.phone ]
                    ]
            )
            (getContactsByLanguage language contacts)
        )


{-| Determine if we have the name of the contact in the given language.
-}
getContactsByLanguage : Language -> List Contact -> List Contact
getContactsByLanguage language contacts =
    List.filter
        (\contact ->
            List.foldl
                (\name accum ->
                    if accum == True then
                        -- We already found a matching language.
                        True
                    else
                        let
                            -- Extract the language form the name.
                            (Name nameLanguage _) =
                                name
                        in
                            language == nameLanguage
                )
                False
                contact.name
        )
        contacts


{-| Get the name by language. In case language doesn't exist, we show an emoty
string, but that should never be the case.
-}
getContactNameByLanguage : Language -> Contact -> String
getContactNameByLanguage language contact =
    List.foldl
        (\name accum ->
            let
                (Name nameLanguage nameString) =
                    name
            in
                if nameLanguage == language then
                    nameString
                else
                    accum
        )
        ""
        contact.name


jsonExample : String
jsonExample =
    """
    { "name" : {
        "arabic" : "foo",
        "hebrew" : "bar"
      },
      "phone" : "1234"
    }
    """


decodeContact : Decoder Contact
decodeContact =
    decode Contact
        |> custom (at [ "name" ] decodeName)
        |> required "phone" string


decodeName : Decoder (List Name)
decodeName =
    Json.keyValuePairs string
        |> andThen
            (\names ->
                let
                    ( validNames, invalidNames ) =
                        List.foldl
                            (\( key, val ) ( validNames, invalidNames ) ->
                                if key == "arabic" then
                                    ( (Name Arabic val) :: validNames
                                    , invalidNames
                                    )
                                else if key == "hebrew" then
                                    ( (Name Hebrew val) :: validNames
                                    , invalidNames
                                    )
                                else
                                    ( validNames, key :: invalidNames )
                            )
                            ( [], [] )
                            names
                in
                    if List.isEmpty invalidNames then
                        succeed validNames
                    else
                        fail <| "Could not recognise names: " ++ String.join ", " invalidNames
            )
	{
	"version": "1.0.0",
	"summary": "Tell the world about your project!",
	"repository": "https://github.com/user/project.git",
	"license": "BSD3",
	"source-directories": [
	"."
	],
	"exposed-modules": [],
	"dependencies": {
	"elm-lang/core": "5.1.1 <= v < 5.1.1",
	"elm-lang/html": "2.0.0 <= v < 2.0.0",
	"NoRedInk/elm-decode-pipeline": "3.0.0 <= v < 3.0.0"
	},
	"elm-version": "0.18.0 <= v < 0.19.0"
	}
	<html>
	<head>
	<style>
	html {
	background: #F7F7F7;
	color: red;
	}
	</style>
	</head>
	<body>
	<script>
	var app = Elm.Main.fullscreen()
	</script>
	</body>
	</html>
	module Main exposing (..)

	import Html exposing (Html, div, li, text, ul)
	import Json.Decode as Json exposing (Decoder, andThen, at, fail, int, list, map, nullable, string, succeed)
	import Json.Decode.Pipeline exposing (custom, decode, hardcoded, optional, required)
	import String exposing (join)


	main : Html a
	main =
	div []
	[ div [] [ text <\| "Showing contacts for language " ++ toString model.language ]
	, viewContacts model.language model.contacts
	]


	type Language
	= Arabic
	\| Hebrew


	type Name
	= Name Language String


	type alias Contact =
	{ name : List Name
	, phone : String
	}


	contact1 : Contact
	contact1 =
	{ name =
	[ Name Arabic "Foo"
	, Name Hebrew "Bar"
	]
	, phone = "1234"
	}


	contact2 : Contact
	contact2 =
	{ name =
	[ Name Hebrew "Nik"
	]
	, phone = "5678"
	}


	type alias Model =
	{ language : Language
	, contacts : List Contact
	}


	model : Model
	model =
	{ language = Hebrew
	, contacts = [ contact1, contact2 ]
	}


	viewContacts : Language -> List Contact -> Html msg
	viewContacts language contacts =
	div []
	(List.map
	(\contact ->
	ul
	[]
	[ li [] [ text <\| getContactNameByLanguage language contact ]
	, li [] [ text contact.phone ]
	]
	)
	(getContactsByLanguage language contacts)
	)


	{-\| Determine if we have the name of the contact in the given language.
	-}
	getContactsByLanguage : Language -> List Contact -> List Contact
	getContactsByLanguage language contacts =
	List.filter
	(\contact ->
	List.foldl
	(\name accum ->
	if accum == True then
	-- We already found a matching language.
	True
	else
	let
	-- Extract the language form the name.
	(Name nameLanguage _) =
	name
	in
	language == nameLanguage
	)
	False
	contact.name
	)
	contacts


	{-\| Get the name by language. In case language doesn't exist, we show an emoty
	string, but that should never be the case.
	-}
	getContactNameByLanguage : Language -> Contact -> String
	getContactNameByLanguage language contact =
	List.foldl
	(\name accum ->
	let
	(Name nameLanguage nameString) =
	name
	in
	if nameLanguage == language then
	nameString
	else
	accum
	)
	""
	contact.name


	jsonExample : String
	jsonExample =
	"""
	{ "name" : {
	"arabic" : "foo",
	"hebrew" : "bar"
	},
	"phone" : "1234"
	}
	"""


	decodeContact : Decoder Contact
	decodeContact =
	decode Contact
	\|> custom (at [ "name" ] decodeName)
	\|> required "phone" string


	decodeName : Decoder (List Name)
	decodeName =
	Json.keyValuePairs string
	\|> andThen
	(\names ->
	let
	( validNames, invalidNames ) =
	List.foldl
	(\( key, val ) ( validNames, invalidNames ) ->
	if key == "arabic" then
	( (Name Arabic val) :: validNames
	, invalidNames
	)
	else if key == "hebrew" then
	( (Name Hebrew val) :: validNames
	, invalidNames
	)
	else
	( validNames, key :: invalidNames )
	)
	( [], [] )
	names
	in
	if List.isEmpty invalidNames then
	succeed validNames
	else
	fail <\| "Could not recognise names: " ++ String.join ", " invalidNames
	)