{-# LANGUAGE OverloadedStrings #-} module Network.Wai.Middleware.MethodOverride ( methodOverride ) where import Network.Wai import Control.Monad (join) -- | Allows overriding of the HTTP request method via the _method query string -- parameter. -- -- This middleware only applies when the initial request method is POST. This -- allow submitting of normal HTML forms, without worries of semantics -- mismatches in the HTTP spec. methodOverride :: Middleware methodOverride app req = app req' where req' = case (requestMethod req, join $ lookup "_method" $ queryString req) of ("POST", Just m) -> req { requestMethod = m } _ -> req