#{pageTitle p} ^{pageHead p} <body> $maybe msg <- mmsg <p .message>#{msg} ^{pageBody p} |] -- | Gets called at the beginning of each request. Useful for logging. -- -- FIXME make this a part of the Yesod middlewares onRequest :: GHandler sub a () onRequest = return () -- | Override the rendering function for a particular URL. One use case for -- this is to offload static hosting to a different domain name to avoid -- sending cookies. urlRenderOverride :: a -> Route a -> Maybe S.ByteString urlRenderOverride _ _ = Nothing -- | Determine if a request is authorized or not. -- -- Return 'Nothing' is the request is authorized, 'Just' a message if -- unauthorized. If authentication is required, you should use a redirect; -- the Auth helper provides this functionality automatically. -- -- FIXME make this a part of the Yesod middlewares isAuthorized :: Route a -> Bool -- ^ is this a write request? -> GHandler s a AuthResult isAuthorized _ _ = return Authorized -- | Determines whether the current request is a write request. By default, -- this assumes you are following RESTful principles, and determines this -- from request method. In particular, all except the following request -- methods are considered write: GET HEAD OPTIONS TRACE. -- -- This function is used to determine if a request is authorized; see -- 'isAuthorized'. isWriteRequest :: Route a -> GHandler s a Bool isWriteRequest _ = do wai <- waiRequest return $ not $ W.requestMethod wai `elem` ["GET", "HEAD", "OPTIONS", "TRACE"] -- | The default route for authentication. -- -- Used in particular by 'isAuthorized', but library users can do whatever -- they want with it. authRoute :: a -> Maybe (Route a) authRoute _ = Nothing -- | A function used to clean up path segments. It returns 'Nothing' when -- the given path is already clean, and a 'Just' when Yesod should redirect -- to the given path pieces. -- -- * No double slashes -- -- * There is no trailing slash. -- -- Note that versions of Yesod prior to 0.7 used a different set of rules -- involing trailing slashes. cleanPath :: a -> [String] -> Maybe [String] cleanPath _ s = if corrected == s then Nothing else Just corrected where corrected = filter (not . null) s -- | Join the pieces of a path together into an absolute URL. This should -- be the inverse of 'splitPath'. joinPath :: a -> S.ByteString -- ^ application root -> [String] -- ^ path pieces -> [(String, String)] -- ^ query string -> S.ByteString joinPath _ ar pieces qs = S.concat [ ar , S8.singleton '/' , S8.pack $ encodePathInfo pieces qs ] -- | This function is used to store some static content to be served as an -- external file. The most common case of this is stashing CSS and -- JavaScript content in an external file; the "Yesod.Widget" module uses -- this feature. -- -- The return value is 'Nothing' if no storing was performed; this is the -- default implementation. A 'Just' 'Left' gives the absolute URL of the -- file, whereas a 'Just' 'Right' gives the type-safe URL. The former is -- necessary when you are serving the content outside the context of a -- Yesod application, such as via memcached. addStaticContent :: String -- ^ filename extension -> String -- ^ mime-type -> L.ByteString -- ^ content -> GHandler sub a (Maybe (Either String (Route a, [(String, String)]))) addStaticContent _ _ _ = return Nothing -- | Whether or not to tie a session to a specific IP address. Defaults to -- 'True'. sessionIpAddress :: a -> Bool sessionIpAddress _ = True data AuthResult = Authorized | AuthenticationRequired | Unauthorized String deriving (Eq, Show, Read) -- | A type-safe, concise method of creating breadcrumbs for pages. For each -- resource, you declare the title of the page and the parent resource (if -- present). class YesodBreadcrumbs y where -- | Returns the title and the parent resource, if available. If you return -- a 'Nothing', then this is considered a top-level page. breadcrumb :: Route y -> GHandler sub y (String, Maybe (Route y)) -- | Gets the title of the current page and the hierarchy of parent pages, -- along with their respective titles. breadcrumbs :: YesodBreadcrumbs y => GHandler sub y (String, [(Route y, String)]) breadcrumbs = do x' <- getCurrentRoute tm <- getRouteToMaster let x = fmap tm x' case x of Nothing -> return ("Not found", []) Just y -> do (title, next) <- breadcrumb y z <- go [] next return (title, z) where go back Nothing = return back go back (Just this) = do (title, next) <- breadcrumb this go ((this, title) : back) next applyLayout' :: Yesod master => Html -- ^ title -> Hamlet (Route master) -- ^ body -> GHandler sub master ChooseRep applyLayout' title body = fmap chooseRep $ defaultLayout $ do setTitle title addHamlet body -- | The default error handler for 'errorHandler'. defaultErrorHandler :: Yesod y => ErrorResponse -> GHandler sub y ChooseRep defaultErrorHandler NotFound = do r <- waiRequest let path' = bsToChars $ W.pathInfo r applyLayout' "Not Found" #if GHC7 [hamlet| #else [$hamlet| #endif <h1>Not Found <p>#{path'} |] defaultErrorHandler (PermissionDenied msg) = applyLayout' "Permission Denied" #if GHC7 [hamlet| #else [$hamlet| #endif <h1>Permission denied <p>#{msg} |] defaultErrorHandler (InvalidArgs ia) = applyLayout' "Invalid Arguments" #if GHC7 [hamlet| #else [$hamlet| #endif <h1>Invalid Arguments <ul> $forall msg <- ia <li>#{msg} |] defaultErrorHandler (InternalError e) = applyLayout' "Internal Server Error" #if GHC7 [hamlet| #else [$hamlet| #endif <h1>Internal Server Error <p>#{e} |] defaultErrorHandler (BadMethod m) = applyLayout' "Bad Method" #if GHC7 [hamlet| #else [$hamlet| #endif <h1>Method Not Supported <p>Method "#{m}" not supported |] -- | Return the same URL if the user is authorized to see it. -- -- Built on top of 'isAuthorized'. This is useful for building page that only -- contain links to pages the user is allowed to see. maybeAuthorized :: Yesod a => Route a -> Bool -- ^ is this a write request? -> GHandler s a (Maybe (Route a)) maybeAuthorized r isWrite = do x <- isAuthorized r isWrite return $ if x == Authorized then Just r else Nothing -- | Convert a widget to a 'PageContent'. widgetToPageContent :: (Eq (Route master), Yesod master) => GWidget sub master () -> GHandler sub master (PageContent (Route master)) widgetToPageContent (GWidget w) = do w' <- flip evalStateT 0 $ runWriterT $ runWriterT $ runWriterT $ runWriterT $ runWriterT $ runWriterT $ runWriterT w let ((((((((), Body body), Last mTitle), scripts'), stylesheets'), style), jscript), Head head') = w' let title = maybe mempty unTitle mTitle let scripts = map (locationToHamlet . unScript) $ runUniqueList scripts' let stylesheets = map (locationToHamlet . unStylesheet) $ runUniqueList stylesheets' let cssToHtml = preEscapedLazyText . renderCss celper :: Cassius url -> Hamlet url celper = fmap cssToHtml jsToHtml (Javascript b) = preEscapedLazyText $ toLazyText b jelper :: Julius url -> Hamlet url jelper = fmap jsToHtml render <- getUrlRenderParams let renderLoc x = case x of Nothing -> Nothing Just (Left s) -> Just s Just (Right (u, p)) -> Just $ render u p cssLoc <- case style of Nothing -> return Nothing Just s -> do x <- addStaticContent "css" "text/css; charset=utf-8" $ encodeUtf8 $ renderCassius render s return $ renderLoc x jsLoc <- case jscript of Nothing -> return Nothing Just s -> do x <- addStaticContent "js" "text/javascript; charset=utf-8" $ encodeUtf8 $ renderJulius render s return $ renderLoc x let head'' = #if GHC7 [hamlet| #else [$hamlet| #endif $forall s <- scripts <script src="^{s}"> $forall s <- stylesheets <link rel="stylesheet" href="^{s}"> $maybe s <- style $maybe s <- cssLoc <link rel="stylesheet" href="#{s}"> $nothing <style>^{celper s} $maybe j <- jscript $maybe s <- jsLoc <script src="#{s}"> $nothing <script>^{jelper j} \^{head'} |] return $ PageContent title head'' body #if TEST coreTestSuite :: Test coreTestSuite = testGroup "Yesod.Yesod" [ testProperty "join/split path" propJoinSplitPath , testCase "join/split path [\".\"]" caseJoinSplitPathDquote , testCase "utf8 split path" caseUtf8SplitPath , testCase "utf8 join path" caseUtf8JoinPath ] data TmpYesod = TmpYesod data TmpRoute = TmpRoute deriving Eq type instance Route TmpYesod = TmpRoute instance Yesod TmpYesod where approot _ = "" fromString :: String -> S8.ByteString fromString = Data.Text.Encoding.encodeUtf8 . Data.Text.pack propJoinSplitPath :: [String] -> Bool propJoinSplitPath ss = splitPath TmpYesod (fromString $ joinPath TmpYesod "" ss' []) == Right ss' where ss' = filter (not . null) ss caseJoinSplitPathDquote :: Assertion caseJoinSplitPathDquote = do splitPath TmpYesod (fromString "/x%2E/") @?= Right ["x."] splitPath TmpYesod (fromString "/y./") @?= Right ["y."] joinPath TmpYesod "" ["z."] [] @?= "/z./" x @?= Right ss where x = splitPath TmpYesod (fromString $ joinPath TmpYesod "" ss' []) ss' = filter (not . null) ss ss = ["a."] caseUtf8SplitPath :: Assertion caseUtf8SplitPath = do Right ["שלום"] @=? splitPath TmpYesod (fromString "/שלום/") Right ["page", "Fooé"] @=? splitPath TmpYesod (fromString "/page/Fooé/") Right ["\156"] @=? splitPath TmpYesod (fromString "/\156/") Right ["ð"] @=? splitPath TmpYesod (fromString "/%C3%B0/") caseUtf8JoinPath :: Assertion caseUtf8JoinPath = do "/%D7%A9%D7%9C%D7%95%D7%9D/" @=? joinPath TmpYesod "" ["שלום"] [] #endif -- | Redirect to a POST resource. -- -- This is not technically a redirect; instead, it returns an HTML page with a -- POST form, and some Javascript to automatically submit the form. This can be -- useful when you need to post a plain link somewhere that needs to cause -- changes on the server. redirectToPost :: Route master -> GHandler sub master a redirectToPost dest = hamletToRepHtml #if GHC7 [hamlet| #else [$hamlet| #endif \<!DOCTYPE html> <html> <head> <title>Redirecting... <body onload="document.getElementById('form').submit()"> <form id="form" method="post" action="@{dest}"> <noscript> <p>Javascript has been disabled; please click on the button below to be redirected. <input type="submit" value="Continue"> |] >>= sendResponse yesodVersion :: String yesodVersion = showVersion Paths_yesod

{-# LANGUAGE QuasiQuotes #-} {-# LANGUAGE RankNTypes #-} {-# LANGUAGE TypeFamilies #-} {-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE MultiParamTypeClasses #-} {-# LANGUAGE OverloadedStrings #-} {-# LANGUAGE CPP #-} -- | The basic typeclass for a Yesod application. module Yesod.Core ( -- * Type classes Yesod (..) , YesodSite (..) , YesodSubSite (..) -- ** Breadcrumbs , YesodBreadcrumbs (..) , breadcrumbs -- * Utitlities , maybeAuthorized , widgetToPageContent , redirectToPost -- * Defaults , defaultErrorHandler -- * Data types , AuthResult (..) -- * Misc , yesodVersion #if TEST , coreTestSuite #endif ) where import Yesod.Content import Yesod.Handler import qualified Paths_yesod_core import Data.Version (showVersion) import Yesod.Widget import Yesod.Request import qualified Network.Wai as W import Yesod.Internal import Web.ClientSession (getKey, defaultKeyFile) import qualified Web.ClientSession as CS import qualified Data.ByteString as S import qualified Data.ByteString.Char8 as S8 import qualified Data.ByteString.Lazy as L import Data.Monoid import Control.Monad.Trans.Writer import Control.Monad.Trans.State hiding (get) import Text.Hamlet import Text.Cassius import Text.Julius import Web.Routes import Text.Blaze (preEscapedLazyText) import Data.Text.Lazy.Builder (toLazyText) import Data.Text.Lazy.Encoding (encodeUtf8) #if TEST import Test.Framework (testGroup, Test) import Test.Framework.Providers.HUnit import Test.Framework.Providers.QuickCheck2 (testProperty) import Test.HUnit hiding (Test) import qualified Data.Text import qualified Data.Text.Encoding #endif #if GHC7 #define HAMLET hamlet #else #define HAMLET $hamlet #endif -- | This class is automatically instantiated when you use the template haskell -- mkYesod function. You should never need to deal with it directly. class Eq (Route y) => YesodSite y where getSite :: Site (Route y) (Method -> Maybe (GHandler y y ChooseRep)) type Method = String -- | Same as 'YesodSite', but for subsites. Once again, users should not need -- to deal with it directly, as the mkYesodSub creates instances appropriately. class Eq (Route s) => YesodSubSite s y where getSubSite :: Site (Route s) (Method -> Maybe (GHandler s y ChooseRep)) getSiteFromSubSite :: s -> Site (Route s) (Method -> Maybe (GHandler s y ChooseRep)) getSiteFromSubSite _ = getSubSite -- | Define settings for a Yesod applications. The only required setting is -- 'approot'; other than that, there are intelligent defaults. class Eq (Route a) => Yesod a where -- | An absolute URL to the root of the application. Do not include -- trailing slash. -- -- If you want to be lazy, you can supply an empty string under the -- following conditions: -- -- * Your application is served from the root of the domain. -- -- * You do not use any features that require absolute URLs, such as Atom -- feeds and XML sitemaps. approot :: a -> S.ByteString -- | The encryption key to be used for encrypting client sessions. -- Returning 'Nothing' disables sessions. encryptKey :: a -> IO (Maybe CS.Key) encryptKey _ = fmap Just $ getKey defaultKeyFile -- | Number of minutes before a client session times out. Defaults to -- 120 (2 hours). clientSessionDuration :: a -> Int clientSessionDuration = const 120 -- | Output error response pages. errorHandler :: ErrorResponse -> GHandler sub a ChooseRep errorHandler = defaultErrorHandler -- | Applies some form of layout to the contents of a page. defaultLayout :: GWidget sub a () -> GHandler sub a RepHtml defaultLayout w = do p <- widgetToPageContent w mmsg <- getMessage hamletToRepHtml [HAMLET| !!! #{pageTitle p} ^{pageHead p} <body> $maybe msg <- mmsg <p .message>#{msg} ^{pageBody p} |] -- | Gets called at the beginning of each request. Useful for logging. -- -- FIXME make this a part of the Yesod middlewares onRequest :: GHandler sub a () onRequest = return () -- | Override the rendering function for a particular URL. One use case for -- this is to offload static hosting to a different domain name to avoid -- sending cookies. urlRenderOverride :: a -> Route a -> Maybe S.ByteString urlRenderOverride _ _ = Nothing -- | Determine if a request is authorized or not. -- -- Return 'Nothing' is the request is authorized, 'Just' a message if -- unauthorized. If authentication is required, you should use a redirect; -- the Auth helper provides this functionality automatically. -- -- FIXME make this a part of the Yesod middlewares isAuthorized :: Route a -> Bool -- ^ is this a write request? -> GHandler s a AuthResult isAuthorized _ _ = return Authorized -- | Determines whether the current request is a write request. By default, -- this assumes you are following RESTful principles, and determines this -- from request method. In particular, all except the following request -- methods are considered write: GET HEAD OPTIONS TRACE. -- -- This function is used to determine if a request is authorized; see -- 'isAuthorized'. isWriteRequest :: Route a -> GHandler s a Bool isWriteRequest _ = do wai <- waiRequest return $ not $ W.requestMethod wai `elem` ["GET", "HEAD", "OPTIONS", "TRACE"] -- | The default route for authentication. -- -- Used in particular by 'isAuthorized', but library users can do whatever -- they want with it. authRoute :: a -> Maybe (Route a) authRoute _ = Nothing -- | A function used to clean up path segments. It returns 'Nothing' when -- the given path is already clean, and a 'Just' when Yesod should redirect -- to the given path pieces. -- -- * No double slashes -- -- * There is no trailing slash. -- -- Note that versions of Yesod prior to 0.7 used a different set of rules -- involing trailing slashes. cleanPath :: a -> [String] -> Maybe [String] cleanPath _ s = if corrected == s then Nothing else Just corrected where corrected = filter (not . null) s -- | Join the pieces of a path together into an absolute URL. This should -- be the inverse of 'splitPath'. joinPath :: a -> S.ByteString -- ^ application root -> [String] -- ^ path pieces -> [(String, String)] -- ^ query string -> S.ByteString joinPath _ ar pieces qs = S.concat [ ar , S8.singleton '/' , S8.pack $ encodePathInfo pieces qs ] -- | This function is used to store some static content to be served as an -- external file. The most common case of this is stashing CSS and -- JavaScript content in an external file; the "Yesod.Widget" module uses -- this feature. -- -- The return value is 'Nothing' if no storing was performed; this is the -- default implementation. A 'Just' 'Left' gives the absolute URL of the -- file, whereas a 'Just' 'Right' gives the type-safe URL. The former is -- necessary when you are serving the content outside the context of a -- Yesod application, such as via memcached. addStaticContent :: String -- ^ filename extension -> String -- ^ mime-type -> L.ByteString -- ^ content -> GHandler sub a (Maybe (Either String (Route a, [(String, String)]))) addStaticContent _ _ _ = return Nothing -- | Whether or not to tie a session to a specific IP address. Defaults to -- 'True'. sessionIpAddress :: a -> Bool sessionIpAddress _ = True data AuthResult = Authorized | AuthenticationRequired | Unauthorized String deriving (Eq, Show, Read) -- | A type-safe, concise method of creating breadcrumbs for pages. For each -- resource, you declare the title of the page and the parent resource (if -- present). class YesodBreadcrumbs y where -- | Returns the title and the parent resource, if available. If you return -- a 'Nothing', then this is considered a top-level page. breadcrumb :: Route y -> GHandler sub y (String, Maybe (Route y)) -- | Gets the title of the current page and the hierarchy of parent pages, -- along with their respective titles. breadcrumbs :: YesodBreadcrumbs y => GHandler sub y (String, [(Route y, String)]) breadcrumbs = do x' <- getCurrentRoute tm <- getRouteToMaster let x = fmap tm x' case x of Nothing -> return ("Not found", []) Just y -> do (title, next) <- breadcrumb y z <- go [] next return (title, z) where go back Nothing = return back go back (Just this) = do (title, next) <- breadcrumb this go ((this, title) : back) next applyLayout' :: Yesod master => Html -- ^ title -> Hamlet (Route master) -- ^ body -> GHandler sub master ChooseRep applyLayout' title body = fmap chooseRep $ defaultLayout $ do setTitle title addHamlet body -- | The default error handler for 'errorHandler'. defaultErrorHandler :: Yesod y => ErrorResponse -> GHandler sub y ChooseRep defaultErrorHandler NotFound = do r <- waiRequest let path' = bsToChars $ W.pathInfo r applyLayout' "Not Found" #if GHC7 [hamlet| #else [$hamlet| #endif <h1>Not Found <p>#{path'} |] defaultErrorHandler (PermissionDenied msg) = applyLayout' "Permission Denied" #if GHC7 [hamlet| #else [$hamlet| #endif <h1>Permission denied <p>#{msg} |] defaultErrorHandler (InvalidArgs ia) = applyLayout' "Invalid Arguments" #if GHC7 [hamlet| #else [$hamlet| #endif <h1>Invalid Arguments <ul> $forall msg <- ia <li>#{msg} |] defaultErrorHandler (InternalError e) = applyLayout' "Internal Server Error" #if GHC7 [hamlet| #else [$hamlet| #endif <h1>Internal Server Error <p>#{e} |] defaultErrorHandler (BadMethod m) = applyLayout' "Bad Method" #if GHC7 [hamlet| #else [$hamlet| #endif <h1>Method Not Supported <p>Method "#{m}" not supported |] -- | Return the same URL if the user is authorized to see it. -- -- Built on top of 'isAuthorized'. This is useful for building page that only -- contain links to pages the user is allowed to see. maybeAuthorized :: Yesod a => Route a -> Bool -- ^ is this a write request? -> GHandler s a (Maybe (Route a)) maybeAuthorized r isWrite = do x <- isAuthorized r isWrite return $ if x == Authorized then Just r else Nothing -- | Convert a widget to a 'PageContent'. widgetToPageContent :: (Eq (Route master), Yesod master) => GWidget sub master () -> GHandler sub master (PageContent (Route master)) widgetToPageContent (GWidget w) = do w' <- flip evalStateT 0 $ runWriterT $ runWriterT $ runWriterT $ runWriterT $ runWriterT $ runWriterT $ runWriterT w let ((((((((), Body body), Last mTitle), scripts'), stylesheets'), style), jscript), Head head') = w' let title = maybe mempty unTitle mTitle let scripts = map (locationToHamlet . unScript) $ runUniqueList scripts' let stylesheets = map (locationToHamlet . unStylesheet) $ runUniqueList stylesheets' let cssToHtml = preEscapedLazyText . renderCss celper :: Cassius url -> Hamlet url celper = fmap cssToHtml jsToHtml (Javascript b) = preEscapedLazyText $ toLazyText b jelper :: Julius url -> Hamlet url jelper = fmap jsToHtml render <- getUrlRenderParams let renderLoc x = case x of Nothing -> Nothing Just (Left s) -> Just s Just (Right (u, p)) -> Just $ render u p cssLoc <- case style of Nothing -> return Nothing Just s -> do x <- addStaticContent "css" "text/css; charset=utf-8" $ encodeUtf8 $ renderCassius render s return $ renderLoc x jsLoc <- case jscript of Nothing -> return Nothing Just s -> do x <- addStaticContent "js" "text/javascript; charset=utf-8" $ encodeUtf8 $ renderJulius render s return $ renderLoc x let head'' = #if GHC7 [hamlet| #else [$hamlet| #endif $forall s <- scripts <script src="^{s}"> $forall s <- stylesheets <link rel="stylesheet" href="^{s}"> $maybe s <- style $maybe s <- cssLoc <link rel="stylesheet" href="#{s}"> $nothing <style>^{celper s} $maybe j <- jscript $maybe s <- jsLoc <script src="#{s}"> $nothing <script>^{jelper j} \^{head'} |] return $ PageContent title head'' body #if TEST coreTestSuite :: Test coreTestSuite = testGroup "Yesod.Yesod" [ testProperty "join/split path" propJoinSplitPath , testCase "join/split path [\".\"]" caseJoinSplitPathDquote , testCase "utf8 split path" caseUtf8SplitPath , testCase "utf8 join path" caseUtf8JoinPath ] data TmpYesod = TmpYesod data TmpRoute = TmpRoute deriving Eq type instance Route TmpYesod = TmpRoute instance Yesod TmpYesod where approot _ = "" fromString :: String -> S8.ByteString fromString = Data.Text.Encoding.encodeUtf8 . Data.Text.pack propJoinSplitPath :: [String] -> Bool propJoinSplitPath ss = splitPath TmpYesod (fromString $ joinPath TmpYesod "" ss' []) == Right ss' where ss' = filter (not . null) ss caseJoinSplitPathDquote :: Assertion caseJoinSplitPathDquote = do splitPath TmpYesod (fromString "/x%2E/") @?= Right ["x."] splitPath TmpYesod (fromString "/y./") @?= Right ["y."] joinPath TmpYesod "" ["z."] [] @?= "/z./" x @?= Right ss where x = splitPath TmpYesod (fromString $ joinPath TmpYesod "" ss' []) ss' = filter (not . null) ss ss = ["a."] caseUtf8SplitPath :: Assertion caseUtf8SplitPath = do Right ["שלום"] @=? splitPath TmpYesod (fromString "/שלום/") Right ["page", "Fooé"] @=? splitPath TmpYesod (fromString "/page/Fooé/") Right ["\156"] @=? splitPath TmpYesod (fromString "/\156/") Right ["ð"] @=? splitPath TmpYesod (fromString "/%C3%B0/") caseUtf8JoinPath :: Assertion caseUtf8JoinPath = do "/%D7%A9%D7%9C%D7%95%D7%9D/" @=? joinPath TmpYesod "" ["שלום"] [] #endif -- | Redirect to a POST resource. -- -- This is not technically a redirect; instead, it returns an HTML page with a -- POST form, and some Javascript to automatically submit the form. This can be -- useful when you need to post a plain link somewhere that needs to cause -- changes on the server. redirectToPost :: Route master -> GHandler sub master a redirectToPost dest = hamletToRepHtml #if GHC7 [hamlet| #else [$hamlet| #endif \<!DOCTYPE html> <html> <head> <title>Redirecting... <body onload="document.getElementById('form').submit()"> <form id="form" method="post" action="@{dest}"> <noscript> <p>Javascript has been disabled; please click on the button below to be redirected. <input type="submit" value="Continue"> |] >>= sendResponse yesodVersion :: String yesodVersion = showVersion Paths_yesod_core.version