support creating new posts

elm/Post.elm

import Date (Date)
import List
import Html (..)
import Html.Attributes as Attr
import Html.Events (on, targetValue, onClick)
import Util.Compare (compareBy, flipCompare)
import Util.Html (viewDate)
import String
import Signal
import LocalChannel as LC
import LocalChannel (LocalChannel)
type alias Post = { title:String, content:String, created:Date }
empty : Post
empty = {title = "", content = "", created = Date.fromTime 0}
compareByDate = compareBy (.created >> Date.toTime)
compareByDateReverse = flipCompare <| compareBy (.created >> Date.toTime)
            h3 [] [text post.title],
            section [] (List.map (\par -> p [] [text par]) paragraphs),
            span [] [text "Written ", viewDate ref post.created]
           ]
           ]
-- an editing interface ...
type alias Model = Post
type Action = NoOp
            | UpdateTitle String
            | UpdateContent String
update : Action -> Model -> Model
update action model =
    case action of
      NoOp -> model
      UpdateTitle title -> { model | title <- title }
      UpdateContent content -> { model | content <- content }
type alias Context = { actions : LocalChannel Action
                     , publish : LocalChannel () }
editingView : Context -> Model -> Html
editingView context model = div [] [
                             input [Attr.type' "text", Attr.placeholder "title",
                                    on "input" targetValue (LC.send context.actions << UpdateTitle)] [text model.title],
                             textarea [Attr.placeholder "write something!",
                                       on "input" targetValue (LC.send context.actions << UpdateContent)] [text model.content],
                             button [onClick (LC.send context.publish ())] [text "publish"]
                            ]

elm/Stream.elm

import String
import Time
import Signal
import LocalChannel
import Post
import Post (Post)
type alias Model =
    { posts         : List Post
    { isEditing     : Bool
    , newPost       : Post.Model
    , posts         : List Post
    , referenceDate : Date
    }
type Action = NoOp
            | CreatePost
            | AddPost ()
            | CancelPost
            | EditPost Post.Action
            | UpdateDate Date
date s = case (Date.fromString s) of
-- view
view model = div [] (List.map (Post.view model.referenceDate) (List.sortWith Post.compareByDateReverse model.posts))
view model = div [] [
              if model.isEditing
              then Post.editingView (Post.Context
                                             (LocalChannel.create EditPost updates)
                                             (LocalChannel.create AddPost updates)) Post.empty
              else button [onClick (Signal.send updates CreatePost)] [text "create new post"],
              div [] (List.map (Post.view model.referenceDate) (List.sortWith Post.compareByDateReverse model.posts))
             ]
-- wiring it all up
initialModel = { posts = posts, referenceDate = date "0" }
initialModel = { isEditing = False, newPost = Post.empty, posts = posts, referenceDate = date "0" }
update : Action -> Model -> Model
update action model =
    case action of
      NoOp -> model
      CreatePost -> { model | isEditing <- True }
      AddPost _ -> { model |
                      isEditing <- False,
                      posts <- let p = model.newPost
                               in { p | created <- model.referenceDate } :: posts }
      CancelPost -> { model | isEditing <- False, newPost <- Post.empty }
      UpdateDate d -> { model | referenceDate <- d }
      EditPost action' -> { model | newPost <- Post.update action' model.newPost }
model : Signal Model
model = Signal.foldp update initialModel <| Signal.merge (Signal.subscribe updates) (Signal.map UpdateDate currentDate)

elm/elm-package.json

    "dependencies": {
        "elm-lang/core": "1.1.1 <= v < 2.0.0",
        "evancz/elm-html": "2.0.0 <= v < 3.0.0",
        "evancz/local-channel": "1.0.0 <= v < 2.0.0",
        "heyLu/elm-format-date": "1.0.0 <= v < 2.0.0"
    }
}
}