Documentation

A Url string - a target page and GET parameters. We only require a constraint of IsString so that construction can be convenient, but rendering will require a monomorphic type.

We choose to not provide a Show instance for UrlString to evade the String demand.

Lifts a raw target path and a GET parameter pair into a UrlString.

Adds another GET parameter pair to a UrlString.

Render the Url String as relative

Render the Url String as grounded

Render the Url String as absolute - getting the root from a MonadReader context. The Monoid instance will be decided monomorphically, therefore a type signature will be needed when ran.

Render the Url String as absolute, but with your own configuration type.

data SiteConfig = SiteConfig { host :: T.Text
                             , cdnHost :: T.Text
                             }
  deriving (Show, Eq)

foo :: HtmlT (Reader SiteConfig) ()
foo = do
  url <- lift $ expandAbsoluteWith ("foo.php" <?> ("bar","baz")) host
  script_ [src_ url] ""

bar :: LT.Text 
bar = (runReader (runTextT foo)) $
  SiteConfig "example.com" "cdn.example.com"

Rendering mode transformer. This isn't an instance of UrlReader - to use, simple lift as many levels as you need:

foo :: Monad m => HtmlT (RelativeUrlT m) ()
foo = do
  path <- lift $ url $ "foo.php" <?> ("bar","baz")
  script_ [src_ path] ""

When rendering foo, simply use the Transformer's run function to convert it to a reader:

bar :: ( Monad m, IsString a, Monoid a ) => m a
bar = (runRelativeUrlT (renderTextT foo)) "example.com"

Concrete Monad for automatically coercing HtmlT's to use a mode of Url rendering (relative, grounded, or absolute).

foo :: HtmlT RelativeUrl ()
foo = do
  path <- lift $ url $ "foo.php" <?> ("bar","baz")
  script_ [src_ path] ""

when running the monad reader, use the runUrlReader member function of the UrlReader typeclass:

bar :: ( IsString a, Monoid a ) => a
bar = (runUrlReader (renderTextT foo)) "example.com"

To change the deployment sheme, simply coerce the environment monad in foo.