Form

Simple forms made easy: A Dict implementation of the core Json.Decode API, with state lifecycle and input helpers for the views.

Types

type Msg

= NoOp

| Focus String

| Blur String

| Input String InputType FieldValue

| Append String

| RemoveItem String Int

| Submit

| Validate

| Reset (List ( String, Field ))

Form messages for update.

type InputType

= Text

| Textarea

| Select

| Radio

| Checkbox

Input types to determine live validation behaviour.

type Form customError output

Form to embed in your model. Type parameters are:

customError - a custom error type to extend built-in errors (set to () if you don't need it)
output - the type of the validation output.

type alias FieldState e a =

{ path : String

, value : Maybe a

, error : Maybe (ErrorValue e)

, liveError : Maybe (ErrorValue e)

, isDirty : Bool

, isChanged : Bool

, hasFocus : Bool

}

Field state containing all necessary data for view and update, can be retrived with Form.getFieldAsString or Form.getFieldAsBool.

path - qualified path of the field in the form, with dots for nested fields (field.subfield)
value - a Maybe of the requested type
error - a Maybe of the field error
liveError - same but with added logic for live validation (see getLiveErrorAt impl)
isDirty - if the field content has been changed since last validation
isChanged - if the field value has changed since last init/reset
hasFocus - if the field is currently focused

Init/update lifecyle

initial : List ( String, Field ) -> Validation e output -> Form e output

Initial form state. See Form.Field for initial fields, and Form.Validate for validation.

update : Validation e output -> Msg -> Form e output -> Form e output

Update form state with the given message

Field state accessors

getFieldAsString : String -> Form e o -> FieldState e String

Get field state at path, with value as a String.

getFieldAsBool : String -> Form e o -> FieldState e Bool

Get field state at path, with value as a Bool.

getListIndexes : String -> Form e o -> List Int

return a list of indexes so one can build qualified names of fields in list.

Global state accessors

getFocus : Form e o -> Maybe String

Return currently focused field, if any.

isSubmitted : Form e o -> Bool

Get form submission state. Useful to show errors on unchanged fields.

getErrors : Form e o -> List ( String, ErrorValue e )

Get list of errors on qualified paths.

getOutput : Form e o -> Maybe o

Get form output, in case of validation success.

getChangedFields : Form e o -> Set String

Get set of changed fields.

greg-enbala/elm-form/1.0.0

Form

Types

Init/update lifecyle

Field state accessors

Global state accessors

Modules