elm-elements-datepicker

A reusable date picker component in Elm with Style Elements.

Installation

elm package install veridit/elm-elements-datepicker

Usage

1. Add a date and the date picker state to your Model.
2. Add a Msg for forwarding messages to the datepicker.
3. Edit init, update and view to use the datepicker.
4. Optionally adjust the settings of the date picker.

Walkthrough

Add a date and the date picker state to your Model.

   
type alias Model =
  { ...
  , date : DatePicker.Model
  , datePicker : DatePicker.UiState
  ...
  }

Add a Msg for forwarding messages to the datepicker.

   
type Msg
  = ...
  | DatePickerMsg DatePicker.Msg
  ...

Edit init, view and update to use the datepicker.

init

   
init : (Model, Cmd Msg)
init = 
    let
        ( datePicker, datePickerCmd ) =
            DatePicker.init 
    in
        ( { date = ... , datePicker = datePicker }
        , Cmd.map DatePickerMsg datePickerCmd
        )

Prepare default settings

datePickerSettings = DatePicker.defaultSettings

view

view : Model -> Element Msg
view model =
    ...
    column []
        [ DatePicker.view
            datePickerSettings
            model.datePicker
            model.date
         |> Html.map DatePickerMsg
        ]

update

update : Msg -> Model -> ( Model, Cmd Msg )
update msg model =
    case msg of
        ...

         DatePickerMsg msg ->
            let
                ( newDatePicker, datePickerCmd, newDate ) =
                    DatePicker.update datePickerSettings model.startDatePicker msg model.date
            in
                ({ model
                    | date = newDate
                    , datePicker = newDatePicker
                 }
                , Cmd.map SetDatePicker datePickerCmd
                )

Adjust the settings of the datepicker (Optional)

someSettings : DatePicker.Settings
someSettings = 
    { defaultSettings
        | inputClassList = [ ( "form-control", True ) ]
        , inputId = Just "datepicker"
    }

Examples

See the examples folder or try it on ellie-app: simple example and bootstrap example.

Styling

The CSS for the date picker is distributed separately. You can grab the compiled CSS from here or you can grab the SCSS source from here.

Architecture

Goals

1. Elm debug compatible.
2. Single source of truth.
3. Simple API for simple usage, advanced API for advanced usage.
4. Embeddable in non elm projects.

Considerations to reach those goals

Elm debug compatible.

The data model inside the date picker can not contain any functions, but functions are used to configure the behaviour of the date picker. Therefore state is stored in the model, and a separate record of configuration is given to the update and view functions, but is not stored in neither the model of the date picker, nor in the model where the date picker is used.

Single source of truth.

By avoiding the storage of a date in the date picker model, the code that embeds the date picker always has access to and control over the date. This is as outlined here

Simple API for simple usage, advanced API for advanced usage.

1. Simple API has no configuration or adjustments.
2. Advanced API for configuration.

Embeddable in non elm projects.

Allow other projects the the speed and stability of Elm by offering an embeddable date picker.

Running the acceptance tests

Prerequisites

• elm reactor - this is most likely already installed if you're using Elm!
• chromedriver (https://sites.google.com/a/chromium.org/chromedriver/). Try brew install chromedriver if you're on OSX.

Install the testing tools

run npm install

build the examples

cd examples && make && cd ..

Run the tests

./run-acceptance-tests

Please file an issue if you have any difficulty running the tests.