Http

Making HTTP requests using an API inspired by Elm's elm/http.

Handlers

data Handler

A handler for making HTTP requests.

handler :: Acquire Handler

Create a Handler for making HTTP requests.

Requests

get :: Typeable a => Handler -> Text -> Expect a -> Task Error a

Create a GET request.

post :: Typeable a => Handler -> Text -> Body -> Expect a -> Task Error a

Create a POST request.

request :: Typeable expect => Handler -> Request expect -> Task Error expect

Create a custom request.

data Request a

A custom request.

Constructors

Request

Fields

• method :: Text

  The request method, like GET or PUT.

• headers :: [Header]

  A list of request headers.

• url :: Text

  The url, like "https://fishes.com/salmon".

• body :: Body

  The request body.

• timeout :: Maybe Int

  The amount of microseconds you're willing to wait before giving up.

• expect :: Expect a

  The type of response you expect back from the request.

data Error

A Request can fail in a couple of ways:

• BadUrl means you did not provide a valid URL.
• Timeout means it took too long to get a response.
• NetworkError means the user turned off their wifi, went in a cave, etc.
• BadStatus means you got a response back, but the status code indicates failure.
• BadBody means you got a response back with a nice status code, but the body of the response was something unexpected. The Text in this cse is the debugging message that explains what went wrong with your JSONT decoder or whatever.

Constructors

BadUrl Text

Timeout

NetworkError Text

BadStatus Int

BadBody Text

Instances

Eq Error

Defined in Http.Internal

Methods

(==) :: Error -> Error -> Bool

(/=) :: Error -> Error -> Bool

Show Error

Defined in Http.Internal

Methods

showsPrec :: Int -> Error -> ShowS

show :: Error -> String

showList :: [Error] -> ShowS

Generic Error

Defined in Http.Internal

Associated Types

type Rep Error :: Type -> Type

Methods

from :: Error -> Rep Error x

to :: Rep Error x -> Error

ToJSON Error

Defined in Http.Internal

Methods

toJSON :: Error -> Value

toEncoding :: Error -> Encoding

toJSONList :: [Error] -> Value

toEncodingList :: [Error] -> Encoding

Exception Error

Defined in Http.Internal

Methods

toException :: Error -> SomeException

fromException :: SomeException -> Maybe Error

displayException :: Error -> String

type Rep Error

Defined in Http.Internal

type Rep Error = D1 ('MetaData "Error" "Http.Internal" "nri-http-0.1.0.1-wFWXzmEvQqBnOxeQq4dqG" 'False) ((C1 ('MetaCons "BadUrl" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedStrict) (Rec0 Text)) :+: C1 ('MetaCons "Timeout" 'PrefixI 'False) (U1 :: Type -> Type)) :+: (C1 ('MetaCons "NetworkError" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedStrict) (Rec0 Text)) :+: (C1 ('MetaCons "BadStatus" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedStrict) (Rec0 Int)) :+: C1 ('MetaCons "BadBody" 'PrefixI 'False) (S1 ('MetaSel ('Nothing :: Maybe Symbol) 'NoSourceUnpackedness 'NoSourceStrictness 'DecidedStrict) (Rec0 Text)))))

Header,

data Header

An HTTP header for configuration requests.

Instances

Eq Header

Defined in Http.Internal

Methods

(==) :: Header -> Header -> Bool

(/=) :: Header -> Header -> Bool

Show Header

Defined in Http.Internal

Methods

showsPrec :: Int -> Header -> ShowS

show :: Header -> String

showList :: [Header] -> ShowS

header :: Text -> Text -> Header

Create a Header.

Body

data Body

Represents the body of a Request.

emptyBody :: Body

Create an empty body for your Request. This is useful for GET requests and POST requests where you are not sending any data.

stringBody :: Text -> Text -> Body

Put some string in the body of your Request.

The first argument is a MIME type of the body. Some servers are strict about this!

jsonBody :: ToJSON body => body -> Body

Put some JSON value in the body of your Request. This will automatically add the Content-Type: application/json header.

bytesBody :: Text -> ByteString -> Body

Put some Bytes in the body of your Request. This allows you to use ByteString to have full control over the binary representation of the data you are sending.

The first argument is a MIME type of the body. In other scenarios you may want to use MIME types like imagepng or imagejpeg instead.

Expect

data Expect a

Logic for interpreting a response body.

expectJson :: FromJSON a => Expect a

Expect the response body to be JSON.

expectText :: Expect Text

Expect the response body to be a Text.

expectWhatever :: Expect ()

Expect the response body to be whatever. It does not matter. Ignore it!

Use with external libraries

withThirdParty :: Handler -> (Manager -> Task e a) -> Task e a

Third party libraries that make HTTP requests often take a Manager. This helper allows us to call such a library using a Handler.

The benefit over using this over using a separate Manager for the external library, is that withThirdParty will ensure HTTP requests made by the external library will get logged.

withThirdPartyIO :: LogHandler -> Handler -> (Manager -> IO a) -> IO a

Like withThirdParty, but runs in IO.