Elm 0.17: Experimenting with patterns to update a model

A.elm

import Html exposing (..)
import Html.App as Html
import Html.Attributes exposing (..)
import Html.Events exposing (onInput)
import String


type alias Model =
  { topic : String }
  
init = 
  ({ topic = "" }, Cmd.none)


main =
  Html.program
    { init = init
    , view = view
    , update = update
    , subscriptions = \_ -> Sub.none
    }

-- UPDATE

type Msg = NewContent String

update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
  case msg of
    NewContent val ->
      ({ model | topic = val }, Cmd.none)  -- Handles the 1 property on the model fine


-- VIEW

view model =
  div []
    [ input [ placeholder "Text to reverse", onInput NewContent, myStyle ] []
    , div [ myStyle ] [ text (String.reverse model.topic) ]
    ]

myStyle =
  style
    [ ("width", "100%")
    , ("height", "40px")
    , ("padding", "10px 0")
    , ("font-size", "2em")
    , ("text-align", "center")
    ]

B.elm

import Html exposing (..)
import Html.App as Html
import Html.Attributes exposing (..)
import Html.Events exposing (onInput)
import String


type alias Model =
  { topic : String }
  
init = 
  ({ topic = "" }, Cmd.none)


main =
  Html.program
    { init = init
    , view = view
    , update = update
    , subscriptions = \_ -> Sub.none
    }

-- UPDATE

type Msg = NewContent String

update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
  case msg of
    NewContent val ->
      (Model val, Cmd.none)  -- Handles the 1 property on the model fine


-- VIEW

view model =
  div []
    [ input [ placeholder "Text to reverse", onInput NewContent, myStyle ] []
    , div [ myStyle ] [ text (String.reverse model.topic) ]
    ]

myStyle =
  style
    [ ("width", "100%")
    , ("height", "40px")
    , ("padding", "10px 0")
    , ("font-size", "2em")
    , ("text-align", "center")
    ]

C.elm

import Html exposing (..)
import Html.App as Html
import Html.Attributes exposing (..)
import Html.Events exposing (onInput)
import String


type alias Model =
  { topic : String
  , id : Int  -- adding another property to the model!!!!
  }
  
  
init = 
  ({ topic = ""
   , id = 1
   }, Cmd.none)


main =
  Html.program
    { init = init
    , view = view
    , update = update
    , subscriptions = \_ -> Sub.none
    }

-- UPDATE

type Msg = NewContent String

update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
  case msg of
    NewContent val ->
      ({ model | topic = val }, Cmd.none)  -- Still updates, even thought the model has 2 properties


-- VIEW

view model =
  div []
    [ input [ placeholder "Text to reverse", onInput NewContent, myStyle ] []
    , div [ myStyle ] [ text (String.reverse model.topic) ]
    ]

myStyle =
  style
    [ ("width", "100%")
    , ("height", "40px")
    , ("padding", "10px 0")
    , ("font-size", "2em")
    , ("text-align", "center")
    ]

D.elm

import Html exposing (..)
import Html.App as Html
import Html.Attributes exposing (..)
import Html.Events exposing (onInput)
import String


type alias Model =
  { topic : String
  , id : Int  -- adding another property to the model!!!!
  }
  
init = 
  ({ topic = ""
   , id = 1
   }, Cmd.none)


main =
  Html.program
    { init = init
    , view = view
    , update = update
    , subscriptions = \_ -> Sub.none
    }

-- UPDATE

type Msg = NewContent String

update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
  case msg of
    NewContent val ->
      (Model val, Cmd.none)  -- CHOKES!!!


-- VIEW

view model =
  div []
    [ input [ placeholder "Text to reverse", onInput NewContent, myStyle ] []
    , div [ myStyle ] [ text (String.reverse model.topic) ]
    ]

myStyle =
  style
    [ ("width", "100%")
    , ("height", "40px")
    , ("padding", "10px 0")
    , ("font-size", "2em")
    , ("text-align", "center")
    ]

E.elm

import Html exposing (..)
import Html.App as Html
import Html.Attributes exposing (..)
import Html.Events exposing (onInput)
import String


type alias Model =
  { topic : String
  , id : Int  -- adding another property to the model!!!!
  }
  
init = 
  ({ topic = ""
   , id = 1
   }, Cmd.none)


main =
  Html.program
    { init = init
    , view = view
    , update = update
    , subscriptions = \_ -> Sub.none
    }

-- UPDATE

type Msg = NewContent String

update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
  case msg of
    NewContent val ->
      (Model val 100, Cmd.none)
      -- Works !!
      -- Model as used in your update examples is a constructor, 
      -- so for a Model with two fields, you can pass it two fields.


-- VIEW

view model =
  div []
    [ input [ placeholder "Text to reverse", onInput NewContent, myStyle ] []
    , div [ myStyle ] [ text (String.reverse model.topic) ]
    ]

myStyle =
  style
    [ ("width", "100%")
    , ("height", "40px")
    , ("padding", "10px 0")
    , ("font-size", "2em")
    , ("text-align", "center")
    ]