WebGear.Middlewares.Path

Middlewares related to route paths.

Documentation

data Path (s :: Symbol)

A path component which is literally matched against the request but discarded after that.

Instances

(KnownSymbol s, MonadState PathInfo m) => Trait (Path s :: Type) Request m

Defined in WebGear.Middlewares.Path

Associated Types

type Attribute (Path s) Request :: Type

type Absence (Path s) Request :: Type

Methods

toAttribute :: Request -> m (Result (Path s) Request)

type Attribute (Path s :: Type) Request

Defined in WebGear.Middlewares.Path

type Attribute (Path s :: Type) Request = ()

type Absence (Path s :: Type) Request

Defined in WebGear.Middlewares.Path

type Absence (Path s :: Type) Request = ()

data PathVar tag val

A path variable that is extracted and converted to a value of type val. The tag is usually a type-level symbol (string) to uniquely identify this variable.

Instances

(FromHttpApiData val, MonadState PathInfo m) => Trait (PathVar tag val :: Type) Request m

Defined in WebGear.Middlewares.Path

Associated Types

type Attribute (PathVar tag val) Request :: Type

type Absence (PathVar tag val) Request :: Type

Methods

toAttribute :: Request -> m (Result (PathVar tag val) Request)

type Attribute (PathVar tag val :: Type) Request

Defined in WebGear.Middlewares.Path

type Attribute (PathVar tag val :: Type) Request = val

type Absence (PathVar tag val :: Type) Request

Defined in WebGear.Middlewares.Path

type Absence (PathVar tag val :: Type) Request = PathVarError

data PathVarError

Failure to extract a PathVar

Constructors

PathVarNotFound

PathVarParseError Text

Instances

Eq PathVarError

Defined in WebGear.Middlewares.Path

Methods

(==) :: PathVarError -> PathVarError -> Bool

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

Read PathVarError

Defined in WebGear.Middlewares.Path

Methods

readsPrec :: Int -> ReadS PathVarError

readList :: ReadS [PathVarError]

readPrec :: ReadPrec PathVarError

readListPrec :: ReadPrec [PathVarError]

Show PathVarError

Defined in WebGear.Middlewares.Path

Methods

showsPrec :: Int -> PathVarError -> ShowS

show :: PathVarError -> String

showList :: [PathVarError] -> ShowS

data PathEnd

Trait to indicate that no more path components are present in the request

Instances

MonadState PathInfo m => Trait PathEnd Request m

Defined in WebGear.Middlewares.Path

Associated Types

type Attribute PathEnd Request :: Type

type Absence PathEnd Request :: Type

Methods

toAttribute :: Request -> m (Result PathEnd Request)

type Attribute PathEnd Request

Defined in WebGear.Middlewares.Path

type Attribute PathEnd Request = ()

type Absence PathEnd Request

Defined in WebGear.Middlewares.Path

type Absence PathEnd Request = ()

path :: forall s ts m a. (KnownSymbol s, MonadRouter m) => RequestMiddleware' m ts (Path s ': ts) a

A middleware that literally matches path s.

The symbol s could contain one or more parts separated by a forward slash character. The route will be rejected if there is no match.

For example, the following code could be used to match the URL path "a/b/c" and then invoke handler:

path @"a/b/c" handler

pathVar :: forall tag val ts m a. (FromHttpApiData val, MonadRouter m) => RequestMiddleware' m ts (PathVar tag val ': ts) a

A middleware that captures a path variable from a single path component.

The value captured is converted to a value of type val via FromHttpApiData. The route will be rejected if the value is not found or cannot be converted.

For example, the following code could be used to read a path component as Int tagged with the symbol "objId", and then invoke handler:

pathVar @"objId" @Int handler

pathEnd :: MonadRouter m => RequestMiddleware' m ts (PathEnd ': ts) a

A middleware that verifies that end of path is reached.

match :: QuasiQuoter

Produces middleware(s) to match an optional HTTP method and some path components.

This middleware matches a prefix of path components, the remaining components can be matched by subsequent uses of match.

This quasiquoter can be used in several ways:

QuasiQuoter	Equivalent Middleware
[match| /a/b/c |]	path @"/a/b/c"
[match| /a/b/objId:Int/d |]	path @"/a/b" . pathVar @"objId" @Int . path @"d"
[match| GET /a/b/c |]	method @GET . path @"/a/b/c"
[match| GET /a/b/objId:Int/d |]	method @GET . path @"/a/b" . pathVar @"objId" @Int . path @"d"

route :: QuasiQuoter

Produces middleware(s) to match an optional HTTP method and the entire request path.

This middleware is intended to be used in cases where the entire path needs to be matched. Use match middleware to match only an initial portion of the path.

This quasiquoter can be used in several ways:

QuasiQuoter	Equivalent Middleware
[route| /a/b/c |]	path @"/a/b/c" . pathEnd
[route| /a/b/objId:Int/d |]	path @"/a/b" . pathVar @"objId" @Int . path @"d" . pathEnd
[route| GET /a/b/c |]	method @GET . path @"/a/b/c" . pathEnd
[route| GET /a/b/objId:Int/d |]	method @GET . path @"/a/b" . pathVar @"objId" @Int . path @"d" . pathEnd