Simple URL DSL for Haskell.
This library tries to make it easier for people to write Url strings,
structurally. Packages like Yesod Routes
do a wonderful job at implementing string-free routing and
references, but sometimes we have to compromise. This tries to make that
compromise less painful.
Use bare combinators to render your strings (kinda useless):
expandRelative $ "foo.php" <?> ("key1","bar") <&> ("key2","baz")
↪ "foo.php?key1=bar&key2=baz"
... or use the MonadReader instance for a configurable host:
let path = runAbsoluteUrlT $ queryUrl $ "foo.php" <?> ("key1","bar") <&> ("key2","baz")
path "example.com"
↪ "example.com/foo.php?key1=bar&key2=baz"
url puts the UrlString in a MonadReader that we can use for applying our
host. We use different monads for different deployment schemes (currently we
have 3 - RelativeUrl, GroundedUrl, and AbsoluteUrl), which we can
integrate in different libraries, like Lucid:
(runAbsoluteUrlT $ renderTextT $ do
foo <- lift $ queryUrl $ "foo" <?> ("bar","baz")
script_ [src_ foo] "" )
) "example.com"
↪ "<script src=\"example.com/foo?bar=baz\"></script>"
... and in Scotty ...
main :: IO ()
main = scottyT 3000
rootConf
rootConf
run
where
rootConf = flip runAbsoluteUrlT "http://example.com"
run :: ( MonadIO m
, MonadReader T.Text m
, Url T.Text m ) =>
ScottyT LT.Text m ()
run = get "/" $ do
path <- lift $ queryUrl $ "foo" <?> ("bar","baz")
text $ LT.fromStrict path
λ> curl localhost:3000/
↪ "http://example.com/foo?bar=baz"
Note that in the scotty example, we don't use one of our deployment schemes -
this is because the scottyT function expects it's underlying monad to be an
instance of MonadIO, which we can only instantiate in our monad transformers.
Please take mind - the string type underlying the Url rendering is generalized
to Data.String.IsString for convenient use with -XOverloadedStrings. However,
due to that generality, we need to specify the monomorphic type (like
Data.Text.Text above).
