heist-1.0.0.0: src/Heist.hs
{-# LANGUAGE BangPatterns #-}
{-# LANGUAGE CPP #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TupleSections #-}
{-|
This module defines the core data types used by Heist. In practice you will
also want to import one or both of "Heist.Compiled" or "Heist.Interpreted" to
get functions needed for writing splices.
The Heist template system allows you to build custom HTML and XML based markup
languages. With Heist you can define your own domain-specific tags
implemented with Haskell and use them in your templates.
-}
module Heist
(
-- * Primary Heist initialization functions
loadTemplates
, reloadTemplates
, addTemplatePathPrefix
, initHeist
, initHeistWithCacheTag
, defaultInterpretedSplices
, defaultLoadTimeSplices
, emptyHeistConfig
-- * Core Heist data types
, SpliceConfig
, HeistConfig
, TemplateRepo
, TemplateLocation
, Template
, TPath
, MIMEType
, DocumentFile(..)
, AttrSplice
, RuntimeSplice
, Chunk
, HeistState
, SpliceError(..)
, HeistT
-- * Lenses (can be used with lens or lens-family)
, scInterpretedSplices
, scLoadTimeSplices
, scCompiledSplices
, scAttributeSplices
, scTemplateLocations
, scCompiledTemplateFilter
, hcSpliceConfig
, hcNamespace
, hcErrorNotBound
, hcInterpretedSplices
, hcLoadTimeSplices
, hcCompiledSplices
, hcAttributeSplices
, hcTemplateLocations
, hcCompiledTemplateFilter
-- * HeistT functions
, templateNames
, compiledTemplateNames
, hasTemplate
, spliceNames
, compiledSpliceNames
, evalHeistT
, getParamNode
, getContext
, getTemplateFilePath
, localParamNode
, getsHS
, getHS
, putHS
, modifyHS
, restoreHS
, localHS
, getDoc
, getXMLDoc
, tellSpliceError
, spliceErrorText
, orError
, Splices
) where
------------------------------------------------------------------------------
import Control.Exception.Lifted
import Control.Monad.State
import Data.ByteString (ByteString)
import qualified Data.ByteString as B
import Data.Either
import qualified Data.Foldable as F
import Data.HashMap.Strict (HashMap)
import qualified Data.HashMap.Strict as Map
import qualified Data.HeterogeneousEnvironment as HE
import Data.Map.Syntax
import Data.Monoid
import Data.Text (Text)
import qualified Data.Text as T
import System.Directory.Tree
import qualified Text.XmlHtml as X
------------------------------------------------------------------------------
import Heist.Common
import qualified Heist.Compiled.Internal as C
import qualified Heist.Interpreted.Internal as I
import Heist.Splices
import Heist.Internal.Types
------------------------------------------------------------------------------
------------------------------------------------------------------------------
-- | The built-in set of splices that you should use in compiled splice mode.
-- This list includes everything from 'defaultInterpretedSplices' plus a
-- splice for the content tag that errors out when it sees any instance of the
-- old content tag, which has now been moved to two separate tags called
-- apply-content and bind-content.
defaultLoadTimeSplices :: MonadIO m => Splices (I.Splice m)
defaultLoadTimeSplices = do
-- To be removed in later versions
defaultInterpretedSplices
"content" #! deprecatedContentCheck
------------------------------------------------------------------------------
-- | The built-in set of static splices. All the splices that used to be
-- enabled by default are included here. To get the normal Heist behavior you
-- should include these in the scLoadTimeSplices list in your SpliceConfig.
-- If you are using interpreted splice mode, then you might also want to bind
-- the 'deprecatedContentCheck' splice to the content tag as a load time
-- splice.
defaultInterpretedSplices :: MonadIO m => Splices (I.Splice m)
defaultInterpretedSplices = do
applyTag ## applyImpl
bindTag ## bindImpl
ignoreTag ## ignoreImpl
markdownTag ## markdownSplice
------------------------------------------------------------------------------
-- | An empty HeistConfig that uses the \"h\" namespace with error checking
-- turned on.
emptyHeistConfig :: HeistConfig m
emptyHeistConfig = HeistConfig mempty "h" True
allErrors :: [Either String (TPath, v)]
-> Either [String] (HashMap TPath v)
allErrors tlist =
case errs of
[] -> Right $ Map.fromList $ rights tlist
_ -> Left errs
where
errs = lefts tlist
------------------------------------------------------------------------------
-- | Loads templates from disk. This function returns just a template map so
-- you can load multiple directories and combine the maps before initializing
-- your HeistState.
loadTemplates :: FilePath -> IO (Either [String] TemplateRepo)
loadTemplates dir = do
d <- readDirectoryWith (loadTemplate dir) dir
#if MIN_VERSION_directory_tree(0,11,0)
return $ allErrors $ F.fold (dirTree d)
#else
return $ allErrors $ F.fold (free d)
#endif
------------------------------------------------------------------------------
-- | Reloads all the templates an an existing TemplateRepo.
reloadTemplates :: TemplateRepo -> IO (Either [String] TemplateRepo)
reloadTemplates repo = do
tlist <- mapM loadOrKeep $ Map.toList repo
return $ allErrors tlist
where
loadOrKeep (p,df) =
case dfFile df of
Nothing -> return $ Right (p, df)
Just fp -> do
df' <- loadTemplate' fp
return $ fmap (p,) $ case df' of
[t] -> t
_ -> Left "Template repo has non-templates"
------------------------------------------------------------------------------
-- | Adds a path prefix to a templates in a map returned by loadTemplates. If
-- you want to add multiple levels of directories, separate them with slashes
-- as in "foo/bar". Using an empty string as a path prefix will leave the
-- map unchanged.
addTemplatePathPrefix :: ByteString -> TemplateRepo -> TemplateRepo
addTemplatePathPrefix dir ts
| B.null dir = ts
| otherwise = Map.fromList $
map (\(x,y) -> (f x, y)) $
Map.toList ts
where
f ps = ps++splitTemplatePath dir
------------------------------------------------------------------------------
-- | Creates an empty HeistState.
emptyHS :: HE.KeyGen -> HeistState m
emptyHS kg = HeistState Map.empty Map.empty Map.empty Map.empty Map.empty
True [] [] 0 [] Nothing kg False Html "" [] False 0
------------------------------------------------------------------------------
-- | This is the main Heist initialization function. You pass in a map of all
-- templates and all of your splices and it constructs and returns a
-- HeistState.
--
-- We don't provide functions to add either type of loadtime splices to your
-- HeistState after initHeist because it doesn't make any sense unless you
-- re-initialize all templates with the new splices. If you add any old-style
-- runtime heist splices after calling this function, they will still work
-- fine if you use Heist.Interpreted.renderTemplate. If you add any templates
-- later, then those templates will be available for interpreted rendering,
-- but not for compiled rendering.
--
-- In the past you could add templates to your HeistState after initialization
-- using its Monoid instance. Due to implementation details, this is no
-- longer possible. All of your templates must be known when you call this
-- function.
initHeist :: Monad n
=> HeistConfig n
-> IO (Either [String] (HeistState n))
initHeist hc = do
keyGen <- HE.newKeyGen
repos <- sequence $ _scTemplateLocations $ _hcSpliceConfig hc
case sequence repos of
Left es -> return $ Left es
Right rs -> initHeist' keyGen hc (Map.unions rs)
------------------------------------------------------------------------------
mkSplicePrefix :: Text -> Text
mkSplicePrefix ns
| T.null ns = ""
| otherwise = ns `mappend` ":"
------------------------------------------------------------------------------
initHeist' :: Monad n
=> HE.KeyGen
-> HeistConfig n
-> TemplateRepo
-> IO (Either [String] (HeistState n))
initHeist' keyGen (HeistConfig sc ns enn) repo = do
let empty = emptyHS keyGen
let (SpliceConfig i lt c a _ f) = sc
etmap <- preproc keyGen lt repo ns
let prefix = mkSplicePrefix ns
let eis = runHashMap $ mapK (prefix<>) i
ecs = runHashMap $ mapK (prefix<>) c
eas = runHashMap $ mapK (prefix<>) a
let hs1 = do
tmap <- etmap
is <- eis
cs <- ecs
as <- eas
return $ empty { _spliceMap = is
, _templateMap = tmap
, _compiledSpliceMap = cs
, _attrSpliceMap = as
, _splicePrefix = prefix
, _errorNotBound = enn
}
either (return . Left) (C.compileTemplates f) hs1
------------------------------------------------------------------------------
-- | Runs preprocess on a TemplateRepo and returns the modified templates.
preproc :: HE.KeyGen
-> Splices (I.Splice IO)
-> TemplateRepo
-> Text
-> IO (Either [String] TemplateRepo)
preproc keyGen splices templates ns = do
let esm = runHashMap splices
case esm of
Left errs -> return $ Left errs
Right sm -> do
let hs = (emptyHS keyGen) { _spliceMap = sm
, _templateMap = templates
, _preprocessingMode = True
, _splicePrefix = mkSplicePrefix ns }
let eval a = evalHeistT a (X.TextNode "") hs
tPairs <- mapM (eval . preprocess) $ Map.toList templates
let bad = lefts tPairs
return $ if not (null bad)
then Left bad
else Right $ Map.fromList $ rights tPairs
------------------------------------------------------------------------------
-- | Processes a single template, running load time splices.
preprocess :: (TPath, DocumentFile)
-> HeistT IO IO (Either String (TPath, DocumentFile))
preprocess (tpath, docFile) = do
let tname = tpathName tpath
!emdoc <- try $ I.evalWithDoctypes tname
:: HeistT IO IO (Either SomeException (Maybe X.Document))
let f !doc = (tpath, docFile { dfDoc = doc })
return $! either (Left . show) (Right . maybe die f) emdoc
where
die = error "Preprocess didn't succeed! This should never happen."
------------------------------------------------------------------------------
-- | Wrapper around initHeist that also sets up a cache tag. It sets up both
-- compiled and interpreted versions of the cache tag splices. If you need to
-- configure the cache tag differently than how this function does it, you
-- will still probably want to pattern your approach after this function's
-- implementation.
initHeistWithCacheTag :: MonadIO n
=> HeistConfig n
-> IO (Either [String] (HeistState n, CacheTagState))
initHeistWithCacheTag (HeistConfig sc ns enn) = do
(ss, cts) <- liftIO mkCacheTag
let tag = "cache"
keyGen <- HE.newKeyGen
erepos <- sequence $ _scTemplateLocations sc
case sequence erepos of
Left es -> return $ Left es
Right repos -> do
-- We have to do one preprocessing pass with the cache setup splice. This
-- has to happen for both interpreted and compiled templates, so we do it
-- here by itself because interpreted templates don't get the same load
-- time splices as compiled templates.
eRawWithCache <- preproc keyGen (tag ## ss) (Map.unions repos) ns
case eRawWithCache of
Left es -> return $ Left es
Right rawWithCache -> do
let sc' = SpliceConfig (tag #! cacheImpl cts) mempty
(tag #! cacheImplCompiled cts)
mempty mempty (const True)
let hc = HeistConfig (mappend sc sc') ns enn
hs <- initHeist' keyGen hc rawWithCache
return $ fmap (,cts) hs