Safe Haskell	None
Language	Haskell2010

Network.Wai.Routing.Route

Synopsis

Documentation

data Routes a m b Source

The Routes monad is used to add routing declarations via addRoute or one of get, post, etc.

Instances

Monad (Routes a m)
Functor (Routes a m)
Applicative (Routes a m)

type App m = RoutingReq -> Continue m -> m ResponseReceived Source

Similar to a WAI Application but for RoutingReq and not specific to IO.

type Continue m = Response -> m ResponseReceived Source

The WAI 3.0 application continuation for arbitrary m instead of IO.

data Meta a Source

Data added to a route via attach is returned in this Meta record.

Constructors

Meta
Fields routeMethod :: !Method routePath :: !ByteString routeMeta :: a

prepare :: Monad m => Routes a m b -> [(ByteString, App m)] Source

Run the Routes monad and return the handlers per path.

route :: Monad m => [(ByteString, App m)] -> Request -> Continue m -> m ResponseReceived Source

Routes requests to handlers based on predicated route declarations. Note that route (prepare ...) behaves like a WAI Application generalised to arbitrary monads.

continue :: Monad m => (a -> m Response) -> a -> Continue m -> m ResponseReceived Source

Prior to WAI 3.0 applications returned a plain Response. continue turns such a function into a corresponding CPS version. For example:

sitemap :: Monad m => Routes a m ()
sitemap = do
    get "/f/:foo" (continue f) $ capture "foo"
    get "/g/:foo" g            $ capture "foo"

f :: Monad m => Int -> m Response
f x = ...

g :: Monad m => Int -> Continue m -> m ResponseReceived
g x k = k $ ...

addRoute Source

Arguments

:: Monad m
=> Method
-> ByteString	path
-> (a -> Continue m -> m ResponseReceived)	handler
-> Predicate RoutingReq Error a	`Predicate`
-> Routes b m ()

Add a route for some Method and path (potentially with variable captures) and constrained by some Predicate.

A route handler is like a WAI Application but instead of Request the first parameter is the result-type of the associated Predicate evaluation. I.e. the handler is applied to the predicate's metadata value iff the predicate is true.

attach :: a -> Routes a m () Source

Add some metadata to the last route.

examine :: Routes a m b -> [Meta a] Source

Get back all attached metadata.

get Source

Arguments

:: Monad m
=> ByteString	path
-> (a -> Continue m -> m ResponseReceived)	handler
-> Predicate RoutingReq Error a	`Predicate`
-> Routes b m ()