/elm-datepicker

A reusable date picker component in Elm 0.19.

Primary LanguageElmBSD 3-Clause "New" or "Revised" LicenseBSD-3-Clause

History

This is a fork of the elm-community/elm-datepicker package ported to support elm 0.19.

elm-datepicker is a reusable date picker component in Elm.

Dependencies

This package depends on justinmimbs/date. It uses its date representation: Dates without time and timezones.

Breaking Changes

During the port to 0.19, two breaking changes were made:

  • parseDate now defaults to Date.fromIsoString. Before it was elm-lang/Date.fromString which was much more flexible

  • The --today-css class is now only added to cells that represent todays or the initialized date. Not the picked date. (Bugfix or Breaking change. You may decide)

Upgrading to 3.0.0

3.0.0 introduces a change in emitted html and the packaged css.

The next and previous month buttons previously were a-tags. These interfered with Browser.application apps. Thus, they were changed to button-tags. (see issue #12 for details).

As this change in emitted html needs a change in css, we recommend you to add the following rule to your css when upgrading to 3.0.0:

.elm-datepicker--prev,
.elm-datepicker--next { background-color: inherit; }

Install

elm install CurrySoftware/elm-datepicker

Usage

The DatePicker.init function initialises the DatePicker. It returns the initialised DatePicker and associated Cmds so it must be done in your program's init or update functions:

Note Make sure you don't throw away the initial Cmd!

init : (Model, Cmd Msg)
...
    let
        ( datePicker, datePickerCmd ) =
            DatePicker.init
    in
        (
            { model | datePicker = datePicker },
            Cmd.map SetDatePicker datePickerCmd
)        )

The DatePicker can be displayed in a view using the DatePicker.view function. It returns its own message type so you should wrap it in one of your own messages using Html.map:

type Msg
    = ...
    | SetDatePicker DatePicker.Msg
    | ...


view : Model -> Html Msg
view model =
    ...
    div [] [
        DatePicker.view
            model.date
            someSettings
            model.startDatePicker
         |> Html.map SetDatePicker
        ]

To handle Msg in your update function, you should unwrap the DatePicker.Msg and pass it down to the DatePicker.update function. The DatePicker.update function returns:

  • the new model
  • a DateEvent that represents three things that can possibly happen during an update:
    • None: Nothing
    • Picked Date: The user might pick a date through clicking or typing
    • FailedInput InputError: Or the user typed a date that is either invalid or disabled

In most use cases, it should suffice to match on Picked Date. Have a look at the simple-nightwatch example for basic error handling with InputError.

To create the settings to pass to update, DatePicker.defaultSettings is provided to make it easier to use. You only have to override the settings that you are interested in.

Note The datepicker does not retain an internal idea of a picked date in its model. That is, it depends completely on you for an idea of what date is chosen, so that third tuple member is important! Evan Czaplicki has a compelling argument for why components should not necessarily have an their own state for the primary data they manage here.

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

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

         SetDatePicker subMsg ->
            let
                ( newDatePicker, dateEvent ) =
                    DatePicker.update someSettings subMsg model.startDatePicker

                date =
                    case dateEvent of
                        Picked newDate ->
                            Just newDate

                        _ ->
                            model.date

            in
                ({ model
                    | date = date
                    , datePicker = newDatePicker
                }
                , Cmd.none)

Examples

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

CSS

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.

Running the acceptance tests

Prerequisites

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.