Copyright	(c) Raghu Kaippully 2020
License	MPL-2.0
Maintainer	rkaippully@gmail.com
Safe Haskell	None
Language	Haskell2010

WebGear.Middlewares.Params

Contents

Traits
Middlewares

Description

Middlewares for handling query parameters

Synopsis

type QueryParam (name :: Symbol) val = QueryParam' Required Strict name val
data QueryParam' (e :: Existence) (p :: ParseStyle) (name :: Symbol) val
data ParamNotFound = ParamNotFound
newtype ParamParseError = ParamParseError Text
queryParam :: forall name val m req a. (KnownSymbol name, FromHttpApiData val, MonadRouter m) => RequestMiddleware' m req (QueryParam name val ': req) a
optionalQueryParam :: forall name val m req a. (KnownSymbol name, FromHttpApiData val, MonadRouter m) => RequestMiddleware' m req (QueryParam' Optional Strict name val ': req) a
lenientQueryParam :: forall name val m req a. (KnownSymbol name, FromHttpApiData val, MonadRouter m) => RequestMiddleware' m req (QueryParam' Required Lenient name val ': req) a
optionalLenientQueryParam :: forall name val m req a. (KnownSymbol name, FromHttpApiData val, MonadRouter m) => RequestMiddleware' m req (QueryParam' Optional Lenient name val ': req) a

Traits

type QueryParam (name :: Symbol) val = QueryParam' Required Strict name val Source #

Capture a query parameter with a specified name and convert it to a value of type val via FromHttpApiData.

data QueryParam' (e :: Existence) (p :: ParseStyle) (name :: Symbol) val Source #

Capture a query parameter with a specified name and convert it to a value of type val via FromHttpApiData. The type parameter e denotes whether the query parameter is required to be present. The parse style parameter p determines whether the conversion is applied strictly or leniently.

Instances

(KnownSymbol name, FromHttpApiData val, Monad m) => Trait (QueryParam' Required Strict name val :: Type) Request m Source #
Instance details Defined in WebGear.Middlewares.Params Associated Types type Attribute (QueryParam' Required Strict name val) Request :: Type Source # type Absence (QueryParam' Required Strict name val) Request :: Type Source # Methods toAttribute :: Request -> m (Result (QueryParam' Required Strict name val) Request) Source #
(KnownSymbol name, FromHttpApiData val, Monad m) => Trait (QueryParam' Required Lenient name val :: Type) Request m Source #
Instance details Defined in WebGear.Middlewares.Params Associated Types type Attribute (QueryParam' Required Lenient name val) Request :: Type Source # type Absence (QueryParam' Required Lenient name val) Request :: Type Source # Methods toAttribute :: Request -> m (Result (QueryParam' Required Lenient name val) Request) Source #
(KnownSymbol name, FromHttpApiData val, Monad m) => Trait (QueryParam' Optional Strict name val :: Type) Request m Source #
Instance details Defined in WebGear.Middlewares.Params Associated Types type Attribute (QueryParam' Optional Strict name val) Request :: Type Source # type Absence (QueryParam' Optional Strict name val) Request :: Type Source # Methods toAttribute :: Request -> m (Result (QueryParam' Optional Strict name val) Request) Source #
(KnownSymbol name, FromHttpApiData val, Monad m) => Trait (QueryParam' Optional Lenient name val :: Type) Request m Source #
Instance details Defined in WebGear.Middlewares.Params Associated Types type Attribute (QueryParam' Optional Lenient name val) Request :: Type Source # type Absence (QueryParam' Optional Lenient name val) Request :: Type Source # Methods toAttribute :: Request -> m (Result (QueryParam' Optional Lenient name val) Request) Source #
type Attribute (QueryParam' Required Strict name val :: Type) Request Source #
Instance details Defined in WebGear.Middlewares.Params type Attribute (QueryParam' Required Strict name val :: Type) Request = val
type Attribute (QueryParam' Required Lenient name val :: Type) Request Source #
Instance details Defined in WebGear.Middlewares.Params type Attribute (QueryParam' Required Lenient name val :: Type) Request = Either Text val
type Attribute (QueryParam' Optional Strict name val :: Type) Request Source #
Instance details Defined in WebGear.Middlewares.Params type Attribute (QueryParam' Optional Strict name val :: Type) Request = Maybe val
type Attribute (QueryParam' Optional Lenient name val :: Type) Request Source #
Instance details Defined in WebGear.Middlewares.Params type Attribute (QueryParam' Optional Lenient name val :: Type) Request = Maybe (Either Text val)
type Absence (QueryParam' Required Strict name val :: Type) Request Source #
Instance details Defined in WebGear.Middlewares.Params type Absence (QueryParam' Required Strict name val :: Type) Request = Either ParamNotFound ParamParseError
type Absence (QueryParam' Required Lenient name val :: Type) Request Source #
Instance details Defined in WebGear.Middlewares.Params type Absence (QueryParam' Required Lenient name val :: Type) Request = ParamNotFound
type Absence (QueryParam' Optional Strict name val :: Type) Request Source #
Instance details Defined in WebGear.Middlewares.Params type Absence (QueryParam' Optional Strict name val :: Type) Request = ParamParseError
type Absence (QueryParam' Optional Lenient name val :: Type) Request Source #
Instance details Defined in WebGear.Middlewares.Params type Absence (QueryParam' Optional Lenient name val :: Type) Request = Void

data ParamNotFound Source #

Indicates a missing query parameter

Constructors

ParamNotFound

Instances

Eq ParamNotFound Source #
Instance details Defined in WebGear.Middlewares.Params Methods (==) :: ParamNotFound -> ParamNotFound -> Bool # (/=) :: ParamNotFound -> ParamNotFound -> Bool #
Read ParamNotFound Source #
Instance details Defined in WebGear.Middlewares.Params Methods readsPrec :: Int -> ReadS ParamNotFound # readList :: ReadS [ParamNotFound] # readPrec :: ReadPrec ParamNotFound # readListPrec :: ReadPrec [ParamNotFound] #
Show ParamNotFound Source #
Instance details Defined in WebGear.Middlewares.Params Methods showsPrec :: Int -> ParamNotFound -> ShowS # show :: ParamNotFound -> String # showList :: [ParamNotFound] -> ShowS #

newtype ParamParseError Source #

Error in converting a query parameter

Constructors

ParamParseError Text

Instances

Eq ParamParseError Source #
Instance details Defined in WebGear.Middlewares.Params Methods (==) :: ParamParseError -> ParamParseError -> Bool # (/=) :: ParamParseError -> ParamParseError -> Bool #
Read ParamParseError Source #
Instance details Defined in WebGear.Middlewares.Params Methods readsPrec :: Int -> ReadS ParamParseError # readList :: ReadS [ParamParseError] # readPrec :: ReadPrec ParamParseError # readListPrec :: ReadPrec [ParamParseError] #
Show ParamParseError Source #
Instance details Defined in WebGear.Middlewares.Params Methods showsPrec :: Int -> ParamParseError -> ShowS # show :: ParamParseError -> String # showList :: [ParamParseError] -> ShowS #

Middlewares

queryParam :: forall name val m req a. (KnownSymbol name, FromHttpApiData val, MonadRouter m) => RequestMiddleware' m req (QueryParam name val ': req) a Source #

A middleware to extract a query parameter and convert it to a value of type val using FromHttpApiData.

Example usage:

queryParam @"limit" @Int handler

The associated trait attribute has type val. This middleware will respond with a 400 Bad Request response if the query parameter is not found or could not be parsed.

optionalQueryParam :: forall name val m req a. (KnownSymbol name, FromHttpApiData val, MonadRouter m) => RequestMiddleware' m req (QueryParam' Optional Strict name val ': req) a Source #

A middleware to extract an optional query parameter and convert it to a value of type val using FromHttpApiData.

Example usage:

optionalQueryParam @"limit" @Int handler

The associated trait attribute has type Maybe val; a Nothing value indicates a missing param. A 400 Bad Request response is returned if the query parameter could not be parsed.

lenientQueryParam :: forall name val m req a. (KnownSymbol name, FromHttpApiData val, MonadRouter m) => RequestMiddleware' m req (QueryParam' Required Lenient name val ': req) a Source #

A middleware to extract a query parameter and convert it to a value of type val using FromHttpApiData.

Example usage:

lenientQueryParam @"limit" @Int handler

The associated trait attribute has type Either Text val. A 400 Bad Request reponse is returned if the query parameter is missing. The parsing is done leniently; the trait attribute is set to Left Text in case of parse errors or Right val on success.

optionalLenientQueryParam :: forall name val m req a. (KnownSymbol name, FromHttpApiData val, MonadRouter m) => RequestMiddleware' m req (QueryParam' Optional Lenient name val ': req) a Source #

A middleware to extract an optional query parameter and convert it to a value of type val using FromHttpApiData.

Example usage:

optionalLenientHeader @"Content-Length" @Integer handler

The associated trait attribute has type Maybe (Either Text val). This middleware never fails.