Ditto.Core

The core module for ditto.

This module provides the Form type and helper functions for constructing typesafe forms inside arbitrary "views" / web frameworks. ditto is meant to be a generalized formlet library used to write formlet libraries specific to a web / gui framework

Form types

The representation of formlets

type FormState m = StateT FormRange m

The Form's state is just the range of identifiers so far

data Form m input err view a

ditto's representation of a formlet

Constructors

Form

Fields

• formDecodeInput :: input -> m (Either err a)

  Decode the value from the input

• formInitialValue :: m a

  The initial value

• formFormlet :: FormState m (View err view, Result err (Proved a))

  A FormState which produced a View and a Result

Instances

Functor m => Bifunctor (Form m input err)

Defined in Ditto.Core

Methods

bimap :: (a -> b) -> (c -> d) -> Form m input err a c -> Form m input err b d

first :: (a -> b) -> Form m input err a c -> Form m input err b c

second :: (b -> c) -> Form m input err a b -> Form m input err a c

(Environment m input, Monoid view, FormError input err) => Monad (Form m input err view)

Defined in Ditto.Core

Methods

(>>=) :: Form m input err view a -> (a -> Form m input err view b) -> Form m input err view b

(>>) :: Form m input err view a -> Form m input err view b -> Form m input err view b

return :: a -> Form m input err view a

fail :: String -> Form m input err view a

Functor m => Functor (Form m input err view)

Defined in Ditto.Core

Methods

fmap :: (a -> b) -> Form m input err view a -> Form m input err view b

(<$) :: a -> Form m input err view b -> Form m input err view a

(Monad m, Monoid view) => Applicative (Form m input err view)

Defined in Ditto.Core

Methods

pure :: a -> Form m input err view a

(<*>) :: Form m input err view (a -> b) -> Form m input err view a -> Form m input err view b

liftA2 :: (a -> b -> c) -> Form m input err view a -> Form m input err view b -> Form m input err view c

(*>) :: Form m input err view a -> Form m input err view b -> Form m input err view b

(<*) :: Form m input err view a -> Form m input err view b -> Form m input err view a

(Monad m, Monoid view, FormError input err, Environment m input) => Alternative (Form m input err view)

Defined in Ditto.Core

Methods

empty :: Form m input err view a

(<|>) :: Form m input err view a -> Form m input err view a -> Form m input err view a

some :: Form m input err view a -> Form m input err view [a]

many :: Form m input err view a -> Form m input err view [a]

(Monad m, Monoid view, Semigroup a) => Semigroup (Form m input err view a)

Defined in Ditto.Core

Methods

(<>) :: Form m input err view a -> Form m input err view a -> Form m input err view a

sconcat :: NonEmpty (Form m input err view a) -> Form m input err view a

stimes :: Integral b => b -> Form m input err view a -> Form m input err view a

(Monad m, Monoid view, Monoid a) => Monoid (Form m input err view a)

Defined in Ditto.Core

Methods

mempty :: Form m input err view a

mappend :: Form m input err view a -> Form m input err view a -> Form m input err view a

mconcat :: [Form m input err view a] -> Form m input err view a

Environment

The interface to a given web framework

class Monad m => Environment m input | m -> input where

The environment typeclass: the interface between ditto and a given framework

Methods

environment :: FormId -> m (Value input)

Instances

Monad m => Environment (WithEnvironment input m) input

Defined in Ditto.Core

Methods

environment :: FormId -> WithEnvironment input m (Value input)

Monad m => Environment (NoEnvironment input m) input

Defined in Ditto.Core

Methods

environment :: FormId -> NoEnvironment input m (Value input)

newtype NoEnvironment input m a

Run the form, but always return the initial value

Constructors

NoEnvironment

Fields

• getNoEnvironment :: m a

Instances

Monad m => Monad (NoEnvironment input m)

Defined in Ditto.Core

Methods

(>>=) :: NoEnvironment input m a -> (a -> NoEnvironment input m b) -> NoEnvironment input m b

(>>) :: NoEnvironment input m a -> NoEnvironment input m b -> NoEnvironment input m b

return :: a -> NoEnvironment input m a

fail :: String -> NoEnvironment input m a

Functor m => Functor (NoEnvironment input m)

Defined in Ditto.Core

Methods

fmap :: (a -> b) -> NoEnvironment input m a -> NoEnvironment input m b

(<$) :: a -> NoEnvironment input m b -> NoEnvironment input m a

Applicative m => Applicative (NoEnvironment input m)

Defined in Ditto.Core

Methods

pure :: a -> NoEnvironment input m a

(<*>) :: NoEnvironment input m (a -> b) -> NoEnvironment input m a -> NoEnvironment input m b

liftA2 :: (a -> b -> c) -> NoEnvironment input m a -> NoEnvironment input m b -> NoEnvironment input m c

(*>) :: NoEnvironment input m a -> NoEnvironment input m b -> NoEnvironment input m b

(<*) :: NoEnvironment input m a -> NoEnvironment input m b -> NoEnvironment input m a

Monad m => Environment (NoEnvironment input m) input

Defined in Ditto.Core

Methods

environment :: FormId -> NoEnvironment input m (Value input)

newtype WithEnvironment input m a

Run the form, but with a given environment function

Constructors

WithEnvironment

Fields

• getWithEnvironment :: ReaderT (FormId -> m (Value input)) m a

Instances

MonadTrans (WithEnvironment input)

Defined in Ditto.Core

Methods

lift :: Monad m => m a -> WithEnvironment input m a

Monad m => Monad (WithEnvironment input m)

Defined in Ditto.Core

Methods

(>>=) :: WithEnvironment input m a -> (a -> WithEnvironment input m b) -> WithEnvironment input m b

(>>) :: WithEnvironment input m a -> WithEnvironment input m b -> WithEnvironment input m b

return :: a -> WithEnvironment input m a

fail :: String -> WithEnvironment input m a

Functor m => Functor (WithEnvironment input m)

Defined in Ditto.Core

Methods

fmap :: (a -> b) -> WithEnvironment input m a -> WithEnvironment input m b

(<$) :: a -> WithEnvironment input m b -> WithEnvironment input m a

Applicative m => Applicative (WithEnvironment input m)

Defined in Ditto.Core

Methods

pure :: a -> WithEnvironment input m a

(<*>) :: WithEnvironment input m (a -> b) -> WithEnvironment input m a -> WithEnvironment input m b

liftA2 :: (a -> b -> c) -> WithEnvironment input m a -> WithEnvironment input m b -> WithEnvironment input m c

(*>) :: WithEnvironment input m a -> WithEnvironment input m b -> WithEnvironment input m b

(<*) :: WithEnvironment input m a -> WithEnvironment input m b -> WithEnvironment input m a

Monad m => Environment (WithEnvironment input m) input

Defined in Ditto.Core

Methods

environment :: FormId -> WithEnvironment input m (Value input)

Monad m => MonadReader (FormId -> m (Value input)) (WithEnvironment input m)

Defined in Ditto.Core

Methods

ask :: WithEnvironment input m (FormId -> m (Value input))

local :: ((FormId -> m (Value input)) -> FormId -> m (Value input)) -> WithEnvironment input m a -> WithEnvironment input m a

reader :: ((FormId -> m (Value input)) -> a) -> WithEnvironment input m a

noEnvironment :: Applicative m => FormId -> m (Value input)

environment which will always return the initial value

Utility functions

(@$) :: Monad m => (view -> view') -> Form m input err view a -> Form m input err view' a infixr 0

infix mapView: succinctly mix the view dsl and the formlets dsl foo @$ do ..

catchFormError :: Monad m => ([err] -> a) -> Form m input err view a -> Form m input err view a

Catch errors purely

catchFormErrorM :: Monad m => Form m input err view a -> ([err] -> Form m input err view a) -> Form m input err view a

Catch errors inside Form / m

eitherForm

Arguments

:: Monad m

=> Text

Identifier for the form

-> Form m input err view a

Form to run

-> m (Either view a)

Result

Evaluate a form

Returns:

Left view

on failure. The view will have already been applied to the errors.

Right a

on success.

getFormId :: Monad m => FormState m FormId

Get a FormId from the FormState

getFormInput :: Environment m input => FormState m (Value input)

Utility function: Get the current input

getFormInput' :: Environment m input => FormId -> FormState m (Value input)

Utility function: Gets the input of an arbitrary FormId.

getFormRange :: Monad m => FormState m FormRange

Utility function: Get the current range

getNamedFormId :: Monad m => Text -> FormState m FormId

Get a FormIdName from the FormState

incrementFormId :: FormId -> FormId

Increment a form ID

isInRange

Arguments

:: FormId

Id to check for

-> FormRange

Range

-> Bool

If the range contains the id

Check if a FormId is contained in a FormRange

mapFormMonad :: Monad f => (forall x. m x -> f x) -> Form m input err view a -> Form f input err view a

Change the underlying Monad of the form, usually a lift or newtype

mapResult :: Monad m => (Result err (Proved a) -> Result err (Proved a)) -> (View err view -> View err view) -> Form m input err view a -> Form m input err view a

Map over the Result and View of a form

mapView

Arguments

:: Functor m

=> (view -> view')

Manipulator

-> Form m input err view a

Initial form

-> Form m input err view' a

Resulting form

Common operations on Forms

Change the view of a form using a simple function

This is useful for wrapping a form inside of a <fieldset> or other markup element.

mkOk :: Monad m => FormId -> view -> a -> FormState m (View err view, Result err (Proved a))

Utility Function: turn a view and pure value into a successful FormState

retainChildErrors :: FormRange -> [(FormRange, e)] -> [e]

Select the errors originating from this form or from any of the children of this form

retainErrors :: FormRange -> [(FormRange, e)] -> [e]

Select the errors for a certain range

runForm :: Monad m => Text -> Form m input err view a -> m (View err view, Result err (Proved a))

Run a form

runForm_ :: Monad m => Text -> Form m input err view a -> m (view, Maybe a)

Run a form, and unwrap the result

successDecode :: Applicative m => a -> input -> m (Either err a)

Always succeed decoding

unitRange :: FormId -> FormRange

Turns a FormId into a FormRange by incrementing the base for the end Id

view :: Monad m => view -> Form m input err view ()

Turn a view into a Form

viewForm

Arguments

:: Monad m

=> Text

form prefix

-> Form m input err view a

form to view

-> m view

Run the form with no environment, return only the html. This means that the values will always be their defaults

pureRes :: (Monad m, Monoid view, FormError input err) => a -> Either err a -> Form m input err view a

lift the result of a decoding to a Form

liftForm :: (Monad m, Monoid view) => m a -> Form m input err view a

Form is a MonadTrans, but we can't have an instance of it because of the order and kind of its type variables