Use ! infix function in update

Repos.elm

module Repos exposing (main)

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 (..)

-- Model

type alias Repo =
  { id : Int
  , name : String
  , htmlUrl : String
  -- , description : String
  , sshUrl : String
  -- , language : String
  , stargazersCount: Int
  , avatarUrl: String }

type alias Model =
  { userName : String
  , resultsFor : String
  , repos : List Repo
  , isLoading : Bool
  , alert : String
  , selected : Int
  , sortBy : SortBy }

type SortBy = Name
    | Stars

initialModel : Model
initialModel =
  { userName = "turbomack"
  , resultsFor = "turbomack"
  , repos = []
  , isLoading = True
  , alert = ""
  , selected = -1
  , sortBy = Name }

isSelected : Model -> Repo -> Bool
isSelected model repo =
  if model.selected == repo.id then True else False

sort : SortBy -> List Repo -> List Repo
sort sortBy repos =
  case sortBy of
    Name ->
      repos |> List.sortBy .name
    Stars ->
      repos |> List.sortBy .stargazersCount |> List.reverse

-- HTTP

reposDecoder : Json.Decoder (List Repo)
reposDecoder =
  Json.list repoDecoder

repoDecoder : Json.Decoder Repo
repoDecoder =
  Json.object6
        Repo
          ("id" := Json.int)
          ("name" := Json.string)
          ("html_url" := Json.string)
          -- ("description" := Json.string)
          ("ssh_url" := Json.string)
          -- ("language" := Json.string)
          ("stargazers_count" := Json.int)
          (Json.at ["owner", "avatar_url"] Json.string)

getUrl : String -> String
getUrl name =
  "https://api.github.com/users/" ++ name ++ "/repos"

fetchData : String -> Cmd Msg
fetchData name =
  let
    url = getUrl name
  in
    Task.perform FetchFail FetchDone (Http.get reposDecoder url)

httpErrorToString : String -> Http.Error -> String
httpErrorToString name err =
  case err of
    Http.Timeout -> "Timeout"
    Http.NetworkError -> "Connection problem"
    Http.UnexpectedPayload _ -> "That's weird. Something is broken!"
    Http.BadResponse status msg ->
      case status of
        404 -> name ++ "not found:("
        _ -> msg

-- Init

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

-- Actions

type Msg = NoOp
    | FetchData String
    | FetchDone (List Repo)
    | FetchFail Http.Error
    | NameChanged String
    | SelectRepo Repo
    | ChangeSort SortBy

update : Msg -> Model -> (Model, Cmd Msg)
update msg model =
  case msg of
    NoOp ->
      model ! []
    FetchData name ->
      { model
        | isLoading = True
        , resultsFor = model.userName }
      ! [ fetchData model.userName ]
    FetchDone results ->
      { model
        | repos = results
        , isLoading = False
        , alert = "" }
       ! []
    FetchFail error ->
      { model
        | repos = []
        , isLoading = False
        , alert = (httpErrorToString model.userName error) }
      ! []
    NameChanged name ->
      { model
        | userName = name }
      ! []
    SelectRepo repo ->
      let
        value =
          if repo.id == model.selected then -1 else repo.id
      in
        { model
          | selected = value }
        ! []
    ChangeSort attr ->
      { model
        | sortBy = attr }
      ! []

-- View

headerView : Model -> Html Msg
headerView model =
  header
    [ class "header" ]
    [ img
      [ src "assets/octocat.png"
      , class "octo-cat" ] []
    , h1
      [ class "headline" ]
      [ text "Repos" ]
    , Html.form
        [ Events.onSubmit (FetchData model.userName)
        , class "search-form" ]
        [ span
          [ class "hint" ]
          [ text "github.com/" ]
        , input
            [ value model.userName
            , Events.onInput NameChanged
            , class "search-field" ] []
        , button
            [ type' "submit"
            , class "submit-btn" ]
            [ text "Go" ] ]]

sortView : Model -> Html Msg
sortView model =
  let
    isActive attr =
      model.sortBy == attr
    classNames attr =
      if isActive attr then "active" else "inactive"
  in
    div
      [ class "sort-filter" ]
      [ button
        [ class (classNames Name)
        , Events.onClick (ChangeSort Name)
        ]
        [ text "name" ]
      , button
        [ class (classNames Stars)
        , Events.onClick (ChangeSort Stars)
        ]
        [ text "stars" ]]

loadingView : Html Msg
loadingView =
  div []
  [ text "loading..." ]

repoView : Model -> Repo -> Html Msg
repoView model repo =
  let
    classNames =
      if isSelected model repo then "repo selected" else "repo"
    cloneValue =
      "git clone " ++ repo.sshUrl
  in
    li
    [ class classNames ]
    [ div
      [ class "repo-main"
      , Events.onClick (SelectRepo repo)
      ]
      [ img
        [ src repo.avatarUrl
        , class "avatar" ] []
      , div
        [ class "repo-info" ]
        [ span
          [ class "stars-count" ]
          [ text ("stars: " ++ (toString repo.stargazersCount)) ]
        , h2
          [ class "repo-name" ]
          [ a
          [ href repo.htmlUrl
          , target "_blank" ]
          [ text repo.name ]]]]
    , div
      [ class "repo-details" ]
      [ div
        [ class "clone" ]
        [ label
          [ class "clone-label"]
          [ text "clone:"
          , input
            [ class "clone-input"
            , disabled True
            , value cloneValue ] []]]]]

reposListView : Model -> Html Msg
reposListView model =
  ul
  [ class "repos-list" ]
  ( model.repos |> sort model.sortBy |> List.map (repoView model) )

alertView : String -> Html Msg
alertView msg =
  div [ class "error alert" ] [ text msg ]

view : Model -> Html Msg
view model =
  let
    content =
      if model.isLoading then loadingView else reposListView model
  in
    div []
    [ a
      [ href "https://github.com/turboMaCk/elm-github-repos"
      , class "fork-link" ]
      [ text "Fork me on Github" ]
    , div
      [ class "app-container" ]
      [ headerView model
      , sortView model
      , div
        [ class "results-for" ]
        [ text ("Results for `" ++ model.resultsFor ++ "`:")]
      , alertView model.alert
      , content ]]

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