haskell-yesod.src.Foundation.hs Maven / Gradle / Ivy
{-# LANGUAGE NoImplicitPrelude #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE MultiParamTypeClasses #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE ViewPatterns #-}
{-# LANGUAGE InstanceSigs #-}
module Foundation where
import Import.NoFoundation
import Control.Monad.Logger (LogSource)
import Yesod.Core.Types (Logger)
import qualified Yesod.Core.Unsafe as Unsafe
-- | The foundation datatype for your application. This can be a good place to
-- keep settings and values requiring initialization before your application
-- starts running, such as database connections. Every handler will have
-- access to the data present here.
data App = App
{ appSettings :: AppSettings
, appStatic :: Static -- ^ Settings for static file serving.
, appHttpManager :: Manager
, appLogger :: Logger
}
-- This is where we define all of the routes in our application. For a full
-- explanation of the syntax, please see:
-- http://www.yesodweb.com/book/routing-and-handlers
--
-- Note that this is really half the story; in Application.hs, mkYesodDispatch
-- generates the rest of the code. Please see the following documentation
-- for an explanation for this split:
-- http://www.yesodweb.com/book/scaffolding-and-the-site-template#scaffolding-and-the-site-template_foundation_and_application_modules
--
-- This function also generates the following type synonyms:
-- type Handler = HandlerFor App
-- type Widget = WidgetFor App ()
mkYesodData "App" $(parseRoutesFile "config/routes.yesodroutes")
-- Please see the documentation for the Yesod typeclass. There are a number
-- of settings which can be configured by overriding methods here.
instance Yesod App where
-- Controls the base of generated URLs. For more information on modifying,
-- see: https://github.com/yesodweb/yesod/wiki/Overriding-approot
approot :: Approot App
approot = ApprootRequest $ \app req ->
case appRoot $ appSettings app of
Nothing -> getApprootText guessApproot app req
Just root -> root
makeSessionBackend :: App -> IO (Maybe SessionBackend)
makeSessionBackend _ = return Nothing
-- Yesod Middleware allows you to run code before and after each handler function.
-- The defaultYesodMiddleware adds the response header "Vary: Accept, Accept-Language" and performs authorization checks.
-- Some users may also want to add the defaultCsrfMiddleware, which:
-- a) Sets a cookie with a CSRF token in it.
-- b) Validates that incoming write requests include that token in either a header or POST parameter.
-- To add it, chain it together with the defaultMiddleware: yesodMiddleware = defaultYesodMiddleware . defaultCsrfMiddleware
-- For details, see the CSRF documentation in the Yesod.Core.Handler module of the yesod-core package.
yesodMiddleware :: ToTypedContent res => Handler res -> Handler res
yesodMiddleware = defaultYesodMiddleware
-- What messages should be logged. The following includes all messages when
-- in development, and warnings and errors in production.
shouldLogIO :: App -> LogSource -> LogLevel -> IO Bool
shouldLogIO app _source level =
return $
appShouldLogAll (appSettings app)
|| level == LevelWarn
|| level == LevelError
makeLogger :: App -> IO Logger
makeLogger = return . appLogger
errorHandler :: ErrorResponse -> Handler TypedContent
errorHandler = defaultErrorHandlerJson
-- Useful when writing code that is re-usable outside of the Handler context.
-- An example is background jobs that send email.
-- This can also be useful for writing code that works across multiple Yesod applications.
instance HasHttpManager App where
getHttpManager :: App -> Manager
getHttpManager = appHttpManager
unsafeHandler :: App -> Handler a -> IO a
unsafeHandler = Unsafe.fakeHandlerGetLogger appLogger
-- Note: Some functionality previously present in the scaffolding has been
-- moved to documentation in the Wiki. Following are some hopefully helpful
-- links:
--
-- https://github.com/yesodweb/yesod/wiki/Sending-email
-- https://github.com/yesodweb/yesod/wiki/Serve-static-files-from-a-separate-domain
-- https://github.com/yesodweb/yesod/wiki/i18n-messages-in-the-scaffolding