Yesod.Form

Parse forms (and query strings).

Data types

data GForm s m xml a

A generic form, allowing you to specifying the subsite datatype, master site datatype, a datatype for the form XML and the return type.

Instances

Monoid xml => Functor (GForm sub url xml)

Monoid xml => Applicative (GForm sub url xml)

IsForm (FormField s m a)

RunForm (GForm s m xml a)

data FormResult a

A form can produce three different results: there was no data available, the data was invalid, or there was a successful parse.

The Applicative instance will concatenate the failure messages in two FormResults.

Constructors

FormMissing

FormFailure [String]

FormSuccess a

Instances

Functor FormResult

Applicative FormResult

Show a => Show (FormResult a)

Monoid m => Monoid (FormResult m)

data Enctype

The encoding type required by a form. The Show instance produces values that can be inserted directly into HTML.

Constructors

UrlEncoded

Multipart

Instances

Bounded Enctype

Enum Enctype

Eq Enctype

Monoid Enctype

ToHtml Enctype

RunForm (GFormMonad s m a)

FormResult ~ formResult => IsForm (GFormMonad s m (formResult a, FieldInfo s m))

data FormFieldSettings

Constructors

FormFieldSettings

Fields

ffsLabel :: String

ffsTooltip :: Html

ffsId :: Maybe String

ffsName :: Maybe String

Instances

IsString FormFieldSettings

newtype Textarea

A newtype wrapper around a String that converts newlines to HTML br-tags.

Constructors

Textarea

Fields

unTextarea :: String

Instances

Eq Textarea

Read Textarea

Show Textarea

ToHtml Textarea

PersistField Textarea

ToFormField Textarea y

ToFormField (Maybe Textarea) y

data FieldInfo sub y

Using this as the intermediate XML representation for fields allows us to write generic field functions and then different functions for producing actual HTML. See, for example, fieldsToTable and fieldsToPlain.

Constructors

FieldInfo

Fields

fiLabel :: Html

fiTooltip :: Html

fiIdent :: String

fiInput :: GWidget sub y ()

fiErrors :: Maybe Html

fiRequired :: Bool

Instances

IsForm (FormField s m a)

FormResult ~ formResult => IsForm (GFormMonad s m (formResult a, FieldInfo s m))

Utilities

formFailures :: FormResult a -> Maybe [String]

Type synonyms

type Form sub y = GForm sub y (GWidget sub y ())

type Formlet sub y a = Maybe a -> Form sub y a

type FormField sub y = GForm sub y [FieldInfo sub y]

type FormletField sub y a = Maybe a -> FormField sub y a

type FormInput sub y = GForm sub y [GWidget sub y ()]

Unwrapping functions

generateForm :: GForm s m xml a -> GHandler s m (xml, Enctype, Html)

Generate a form, feeding it no data. The third element in the result tuple is a nonce hidden field.

runFormGet :: GForm s m xml a -> GHandler s m (FormResult a, xml, Enctype)

Run a form against GET parameters.

runFormMonadGet :: GFormMonad s m a -> GHandler s m (a, Enctype)

runFormPost :: GForm s m xml a -> GHandler s m (FormResult a, xml, Enctype, Html)

Run a form against POST parameters.

This function includes CSRF protection by checking a nonce value. You must therefore embed this nonce in the form as a hidden field; that is the meaning of the fourth element in the tuple.

runFormPostNoNonce :: GForm s m xml a -> GHandler s m (FormResult a, xml, Enctype)

Run a form against POST parameters, without CSRF protection.

runFormMonadPost :: GFormMonad s m a -> GHandler s m (a, Enctype)

Run a form against POST parameters. Please note that this does not provide CSRF protection.

runFormGet' :: GForm sub y xml a -> GHandler sub y a

Run a form against GET parameters, disregarding the resulting HTML and returning an error response on invalid input.

runFormPost' :: GForm sub y xml a -> GHandler sub y a

Run a form against POST parameters, disregarding the resulting HTML and returning an error response on invalid input. Note: this does not perform CSRF protection.

High-level form post unwrappers

runFormTable :: Route m -> String -> FormField s m a -> GHandler s m (FormResult a, GWidget s m ())

Create a table-styled form.

This function wraps around runFormPost and fieldsToTable, taking care of some of the boiler-plate in creating forms. In particular, is automatically creates the form element, sets the method, action and enctype attributes, adds the CSRF-protection nonce hidden field and inserts a submit button.

runFormDivs :: Route m -> String -> FormField s m a -> GHandler s m (FormResult a, GWidget s m ())

Same as runFormPostTable, but uses fieldsToDivs for styling.

Field/form helpers

fieldsToTable :: FormField sub y a -> Form sub y a

Display the label, tooltip, input code and errors in a single row of a table.

fieldsToDivs :: FormField sub y a -> Form sub y a

Display the label, tooltip, input code and errors in a single div.

fieldsToPlain :: FormField sub y a -> Form sub y a

Display only the actual input widget code, without any decoration.

checkForm :: (a -> FormResult b) -> GForm s m x a -> GForm s m x b

Add a validation check to a form.

Note that if there is a validation error, this message will not automatically appear on the form; for that, you need to use checkField.

Type classes

module Yesod.Form.Class

Template Haskell

mkToForm :: PersistEntity v => v -> Q [Dec]

Create ToForm instances for the given entity. In addition to regular EntityDef attributes understood by persistent, it also understands label= and tooltip=.

module Yesod.Form.Fields