On Fri, Jan 13, 2012 at 7:23 PM, Anupam Jain
Hi,
I couldn't find any library that provides typesafe URLs for plain Wai applications so I modified the code in Yesod.Dispatch (yesod-core) and created wai-routes. This is my first time writing TH code so I stuck to "tweaking" the existing functionality.
http://hackage.haskell.org/package/wai-routes
Currently it allows you to define type safe URLs in a manner similar to Yesod. It also provides Middleware to easily insert dispatching into your application.
A sample application that provides a JSON API (using aeson) -
============================================ -- A useful type synonym type UserId = Text
-- Define the JSON instance data User = User { name::Text, uid:: UserId } deriving (Show, Read, Eq) instance ToJSON User where toJSON x = object [ "name" .= (name x), "uid" .= (uid x) ]
-- Define the handlers getUserR :: UserId -> Application getUserR uid _req = return $ responseLBS statusOK headers json where user = User { name = "Anon Amos", uid = uid } json = encode user headers = [("Content-Type", "application/json")]
getUsersR :: Application getUsersR _req = return $ responseLBS statusOK headers json where userids = (["anon","john","jane"]::[Text]) json = encode userids headers = [("Content-Type", "application/json")]
-- Generate the routing datatype and the Route instance -- The type generated will be named "UserRoute" mkRoute "User" [parseRoutes| /users UsersR GET /user/#UserId UserR GET |]
-- Now you can use dispatch function (passing it your route datatype) main :: IO () main = run 8080 $ dispatch (undefined::UserRoute) $ staticApp defaultFileServerSettings ============================================
Thanks, Anupam Jain
Very cool! You might want to look at the code in Yesod 0.10 (on the Github repo), which has a much more efficient dispatch mechanism. The yesod-routes package in there is not actually dependent on Yesod in any way; instead, all of Yesod depends on it. That package itself may be 95% of what you're looking for in wai-routes. Michael