elm-validation

Tools for managing validity and error state of data, e.g. from user input.

To install

$ elm install ericgj/elm-validation

Example

Basic usage for validation in an HTML form.

view : Form -> Html Msg
view form =
    div []
        [ input
            [ type_ "text"
            , value
                (form.input
                    |> Validation.toString identity
                )
            , onInput
                (Validation.validate isRequired
                    >> SetInput
                )
            ]
            []
        , div 
            [ class "error" ]
            [ text
                (Validation.message form.input
                    |> Maybe.withDefault ""
                )
            ]
        ]

Combining validation of form fields to determine overall validity of a model. (For example, this could be used to determine if the submit button should be enabled on the form.)

validateForm : Form -> ValidationResult Model
validateForm form =
    Validation.valid Model
        |> Validation.andMap form.field1
        |> Validation.andMap form.field2

See the Elm package for full usage docs.