Deprecated

In favour of

servant-jquery

Automatically derive (jquery) javascript functions to query servant webservices

http://haskell-servant.github.io/

Version on this page:0.4.4.6
LTS Haskell 5.18:0.4.4.7
Stackage Nightly 2016-04-28:0.4.4.7
Latest on Hackage:0.4.4.7

See all snapshots servant-jquery appears in

BSD-3-Clause licensed by Alp Mestanogullari
Maintained by [email protected]
This version can be pinned in stack with:servant-jquery-0.4.4.6@sha256:f3836617b2337cc48f31dac2a840cd6227662d3a476a5223c42826142051d45b,2264

Module documentation for 0.4.4.6

servant-jquery

servant

This library lets you derive automatically (JQuery based) Javascript functions that let you query each endpoint of a servant webservice.

Example

Read more about the following example here.

{-# LANGUAGE DataKinds #-}
{-# LANGUAGE TypeOperators #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE GeneralizedNewtypeDeriving #-}

import Control.Concurrent.STM
import Control.Monad.IO.Class
import Data.Aeson
import Data.Proxy
import GHC.Generics
import Network.Wai.Handler.Warp (run)
import Servant
import Servant.JQuery
import System.FilePath

-- * A simple Counter data type
newtype Counter = Counter { value :: Int }
  deriving (Generic, Show, Num)

instance ToJSON Counter

-- * Shared counter operations

-- Creating a counter that starts from 0
newCounter :: IO (TVar Counter)
newCounter = newTVarIO 0

-- Increasing the counter by 1
counterPlusOne :: MonadIO m => TVar Counter -> m Counter
counterPlusOne counter = liftIO . atomically $ do
  oldValue <- readTVar counter
  let newValue = oldValue + 1
  writeTVar counter newValue
  return newValue

currentValue :: MonadIO m => TVar Counter -> m Counter
currentValue counter = liftIO $ readTVarIO counter

-- * Our API type
type TestApi = "counter" :> Post Counter -- endpoint for increasing the counter
          :<|> "counter" :> Get  Counter -- endpoint to get the current value
          :<|> Raw                       -- used for serving static files

testApi :: Proxy TestApi
testApi = Proxy

-- * Server-side handler

-- where our static files reside
www :: FilePath
www = "examples/www"

-- defining handlers
server :: TVar Counter -> Server TestApi
server counter = counterPlusOne counter     -- (+1) on the TVar
            :<|> currentValue counter       -- read the TVar
            :<|> serveDirectory www         -- serve static files

runServer :: TVar Counter -- ^ shared variable for the counter
          -> Int          -- ^ port the server should listen on
          -> IO ()
runServer var port = run port (serve testApi $ server var)

-- * Generating the JQuery code

incCounterJS :<|> currentValueJS :<|> _ = jquery testApi

writeJS :: FilePath -> [AjaxReq] -> IO ()
writeJS fp functions = writeFile fp $
  concatMap generateJS functions

main :: IO ()
main = do
  -- write the JS code to www/api.js at startup
  writeJS (www </> "api.js")
          [ incCounterJS, currentValueJS ]

  -- setup a shared counter
  cnt <- newCounter

  -- listen to requests on port 8080
  runServer cnt 8080

Changes

0.4.3

  • Content type now set to JSON when a request body is sent (#122)

0.4

0.2.2