@teamthread/elm-web-components

elm-web-components

A small JavaScript package to let you wrap your Elm applications up in a web component.

Install

yarn add @teamthread/elm-web-components

Example

Given the following Elm app:

module Main exposing (..)

import Html exposing (text, Html)

type Msg
    = NoOp


type alias Model =
    { name : String
    }


update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
    ( model, Cmd.none )

view : Model -> Html Msg
view model =
  text ("Hello world, my name is: " ++ model.name)


type alias Flags =
    { name : String }

init : Flags -> ( Model, Cmd Msg )
init flags =
    ( Model flags.name, Cmd.none )


main : Program Flags Model Msg
main =
    Html.programWithFlags
        { init = init, update = update, subscriptions = \_ -> Sub.none, view = view }

You can create a custom web element that will render it like so:

import elmWebComponents from '@teamthread/elm-web-components'
import ElmApp from './Main.elm'

elmWebComponents.register('demo-elm-component', ElmApp.Main)

And now in your HTML you can use the component:

<demo-elm-component name="Jack"></demo-elm-component>

Any attributes are passed into your Elm app as Flags, so make sure you use programWithFlags if you care about them. If you don't you can just use Html.program as you would normally.

Ports

You can also hook up a component that uses ports. The third argument to elmWebComponents.register is a function that will be called with the ports object that Elm provides, so you can then hook into it and subscribe and send to them as you would normally:

elmWebComponents.register('component-with-ports', ComponentWithPorts, ports =>
  ports.somePort.send(1)
  ports.someOtherPort.subscribe(...)
)

You can find a full example of this in the example directory.