wai 3.0.2 → 3.0.2.1

raw patch · 3 files changed

+120/−1 lines, 3 files

Files

• ChangeLog.md +1/−0
• README.md +116/−0
• wai.cabal +3/−1

@@ -0,0 +1,1 @@+No changes logged yet.

@@ -0,0 +1,116 @@+WAI: Web Application Interface+==============================++Getting started+---------------++You want a minimal example? Here it is!++~~~ {.haskell}+{-# LANGUAGE OverloadedStrings #-}+import Network.Wai+import Network.HTTP.Types+import Network.Wai.Handler.Warp (run)++app :: Application+app _ respond = do+    putStrLn "I've done some IO here"+    respond $ responseLBS+        status200+        [("Content-Type", "text/plain")]+        "Hello, Web!"++main :: IO ()+main = do+    putStrLn $ "http://localhost:8080/"+    run 8080 app+~~~++Put that code into a file named _hello.hs_ and install [wai] and [warp] from Hackage:++    cabal install wai warp++Run it:++    runhaskell hello.hs++Point your browser to:++    http://localhost:8080/+++Serving static content+----------------------++We can modify our previous example to serve static content. For this create a file named _index.html_:++    <p>Hello, Web!</p>++Now we redefine `responseBody` to refer to that file:++~~~ {.haskell}+app2 :: Application+app2 _ respond = respond index++index :: Response+index = responseFile+    status200+    [("Content-Type", "text/html")]+    "index.html"+    Nothing+~~~+++Basic dispatching+-----------------++An `Application` maps `Request`s to `Response`s:++    ghci> :info  Application+    type Application = Request -> IO Response++Depending on the path info provided with each `Request` we can serve different `Response`s:++~~~ {.haskell}+app3 :: Application+app3 request respond = respond $ case rawPathInfo request of+    "/"     -> index+    "/raw/" -> plainIndex+    _       -> notFound++plainIndex :: Response+plainIndex = responseFile+    status200+    [("Content-Type", "text/plain")]+    "index.html"+    Nothing++notFound :: Response+notFound = responseLBS+    status404+    [("Content-Type", "text/plain")]+    "404 - Not Found"+~~~+++Doing without overloaded strings+--------------------------------++For the sake of efficiency, WAI uses the [bytestring] package.  We used GHCs [overloaded strings] to almost hide this fact. But we can easily do without.  What follows is a more verbose definition of `notFound`, that works without GHC extensions:++~~~ {.haskell .ignore}+import qualified Data.ByteString.Char8 as B8+import qualified Data.ByteString.Lazy.Char8 as LB8+import           Data.CaseInsensitive (mk)++notFound = responseLBS+    status404+    [(mk $ B8.pack "Content-Type", B8.pack "text/plain")]+    (LB8.pack "404 - Not Found")+~~~+++ [wai]: http://hackage.haskell.org/package/wai+ [warp]: http://hackage.haskell.org/package/warp+ [overloaded strings]: http://www.haskell.org/ghc/docs/latest/html/users_guide/type-class-extensions.html#overloaded-strings+ [bytestring]: http://hackage.haskell.org/package/bytestring

@@ -1,7 +1,8 @@ Name:                wai-Version:             3.0.2+Version:             3.0.2.1 Synopsis:            Web Application Interface. Description:         Provides a common protocol for communication between web applications and web servers.+description:         API docs and the README are available at <http://www.stackage.org/package/wai>. License:             MIT License-file:        LICENSE Author:              Michael Snoyman@@ -11,6 +12,7 @@ Build-Type:          Simple Cabal-Version:       >=1.8 Stability:           Stable+extra-source-files:  README.md ChangeLog.md  Source-repository head     type:            git