Fregelet

A very basic web framework for Frege on top of Servlet

Run via maven

1. mvn install
2. mvn exec:exec

Example

Start server

config = ServerConfig {
    port = 8080,

    routes = [
      ("/greet/:name", [Get, Post], greet),
      ("/date", [Get], date),
      ("/download", [Get], downloadCsv)
    ]
  }

main = startServer config

To try it in your browser, go to:

http://0.0.0.0:8080/greet/Foo

Send JSON

data Greeting = Greeting { message :: String }

instance ToJSON Greeting where
    toJSON Greeting { message } = Struct [ assoc "message" message ]

greet :: Handler ()
greet = do
  name ← pathParam "name"
  let greeting = Greeting $ "Hello, " ++ (fromMaybe "there" name)
  sendJSON greeting

Send simple text

date :: Handler ()
date = liftIO (Date.new () >>= _.toString) >>= sendText

Write directly to response

downloadCsv :: Handler ()
downloadCsv = do
  web ← Handler.ask
  let response = web.response
      csvData = "foo,bar,baz"
      sendCsv = do
        response.setContentType "text/csv"
        response.setHeader "Content-Disposition" "attachment; fileName=output.csv"
        response.write csvData
  liftIO sendCsv