817d204 · typeable/pandoc

git.iko.soy/typeable/pandoc

Improved template API and fixed a bug. Closes #5979.

* Text.Pandoc.Templates [API change] + Add Monad wrappers `WithDefaultPartials` and `WithPartials`. Wrapping these around an instance of `PandocMonad` gives us different instances of `TemplateMonad`, with different search behavior in retrieving partials. To compile a template and limit partial search to pandoc's data files, use `runWithDefaultPartials (compileTemplate ...)`. To compile a template and allow partials to be found locally (either on the file system or via HTTP, in the event that the main template has an absolute URL), ue `runWithPartials (compileTemplate ...)`. + Export `getTemplate`, which seeks a template locally, or via HTTP if the template has an absolute URL, falling back to the data files if not found. + Export `compileDefaultTemplate` -- does `getDefaultTemplate` and compiles the result, raising an error on failure. * Text.Pandoc.Class [API change] + Remove `TemplateMonad` instances for `PandocIO` and `PandocPure`. These were too limiting and caused a bug whereby a local partial could be used even when the default template was requested. We now rely on instances provided in the Templates module. Text.Pandoc.App.OutputSettings + Simplify template retrieval code.

commit817d2048da08f44ab4a9efae7c761aff99e3d959 authorJohn MacFarlane <jgm@berkeley.edu> dateWed 11 Dec 2019, 10:29 (7 years ago) parent4e7ac06

3 files changed+65−43

compare with master

unifiedsplit

src/Text/Pandoc/App/OutputSettings.hs+7−29 src/Text/Pandoc/Class.hs−11 src/Text/Pandoc/Templates.hs+58−3

src/Text/Pandoc/App/OutputSettings.hs+7−29

@@ -25,7 +25,7 @@ import qualified Data.Text as T

2525import Text.DocTemplates (toVal, Context(..), Val(..))

2626import qualified Control.Exception as E

2727import Control.Monad

28−import Control.Monad.Except (catchError, throwError)

28+import Control.Monad.Except (throwError)

2929import Control.Monad.Trans

3030import Data.Char (toLower)

3131import Data.List (find, isPrefixOf)

@@ -171,40 +171,18 @@ optToOutputSettings opts = do

171171 setVariableM "dzslides-core" dzcore vars

172172 else return vars)

173173

174− templStr <- case optTemplate opts of

174+ templ <- case optTemplate opts of

175175 _ | not standalone -> return Nothing

176− Nothing -> Just <$> getDefaultTemplate format

176+ Nothing -> Just <$> compileDefaultTemplate format

177177 Just tp -> do

178178 -- strip off extensions

179179 let tp' = case takeExtension tp of

180180 "" -> tp <.> T.unpack format

181181 _ -> tp

182− Just . UTF8.toText <$>

183− ((do surl <- stSourceURL <$> getCommonState

184− -- we don't want to look for templates remotely

185− -- unless the full URL is specified:

186− modifyCommonState $ \st -> st{

187− stSourceURL = Nothing }

188− (bs, _) <- fetchItem $ T.pack tp'

189− modifyCommonState $ \st -> st{

190− stSourceURL = surl }

191− return bs)

192− `catchError`

193− (\e ->

194− case e of

195− PandocResourceNotFound _ ->

196− readDataFile ("templates" </> tp')

197− _ -> throwError e))

198−

199− let templatePath = fromMaybe "" $ optTemplate opts

200−

201− templ <- case templStr of

202− Nothing -> return Nothing

203− Just ts -> do

204− res <- compileTemplate templatePath ts

205− case res of

206− Left e -> throwError $ PandocTemplateError $ T.pack e

207− Right t -> return $ Just t

182+ res <- getTemplate tp' >>= runWithPartials . compileTemplate tp'

183+ case res of

184+ Left e -> throwError $ PandocTemplateError $ T.pack e

185+ Right t -> return $ Just t

208186

209187 let writerOpts = def {

210188 writerTemplate = templ

src/Text/Pandoc/Class.hs−11

@@ -91,7 +91,6 @@ import Text.Parsec (ParsecT, getPosition, sourceLine, sourceName)

9191import qualified Data.Time as IO (getCurrentTime)

9292import Text.Pandoc.MIME (MimeType, getMimeType, extensionFromMimeType)

9393import Text.Pandoc.Definition

94−import Text.DocTemplates (TemplateMonad(..))

9594import Data.Digest.Pure.SHA (sha1, showDigest)

9695import Data.Maybe (fromMaybe)

9796import Data.Time.Clock.POSIX ( utcTimeToPOSIXSeconds

@@ -315,16 +314,6 @@ readFileFromDirs (d:ds) f = catchError

315314 ((Just . T.pack . UTF8.toStringLazy) <$> readFileLazy (d </> f))

316315 (\_ -> readFileFromDirs ds f)

317316

318−instance TemplateMonad PandocIO where

319− getPartial fp = UTF8.toText <$> catchError

320− (readFileStrict fp)

321− (\_ -> readDataFile ("templates" </> fp))

322−

323−instance TemplateMonad PandocPure where

324− getPartial fp = UTF8.toText <$> catchError

325− (readFileStrict fp)

326− (\_ -> readDataFile ("templates" </> fp))

327−

328317-- | 'CommonState' represents state that is used by all

329318-- instances of 'PandocMonad'. Normally users should not

330319-- need to interact with it directly; instead, auxiliary

src/Text/Pandoc/Templates.hs+58−3

@@ -1,3 +1,4 @@

1+{-# LANGUAGE GeneralizedNewtypeDeriving #-}

12{-# LANGUAGE MultiParamTypeClasses #-}

23{-# LANGUAGE ScopedTypeVariables #-}

34{-# LANGUAGE OverloadedStrings #-}

@@ -14,18 +15,61 @@ Utility functions for working with pandoc templates.

1415-}

1516

1617module Text.Pandoc.Templates ( Template

18+ , WithDefaultPartials(..)

19+ , WithPartials(..)

1720 , compileTemplate

1821 , renderTemplate

22+ , getTemplate

1923 , getDefaultTemplate

24+ , compileDefaultTemplate

2025 ) where

2126

2227import Prelude

2328import System.FilePath ((<.>), (</>))

24−import Text.DocTemplates (Template, compileTemplate, renderTemplate)

25−import Text.Pandoc.Class (PandocMonad, readDataFile)

29+import Text.DocTemplates (Template, TemplateMonad(..), compileTemplate, renderTemplate)

30+import Text.Pandoc.Class (PandocMonad, readDataFile, fetchItem,

31+ CommonState(..), getCommonState, modifyCommonState)

2632import qualified Text.Pandoc.UTF8 as UTF8

33+import Control.Monad.Except (catchError, throwError)

2734import Data.Text (Text)

2835import qualified Data.Text as T

36+import Text.Pandoc.Error

37+

38+-- | Wrap a Monad in this if you want partials to

39+-- be taken only from the default data files.

40+newtype WithDefaultPartials m a = WithDefaultPartials { runWithDefaultPartials :: m a }

41+ deriving (Functor, Applicative, Monad)

42+

43+-- | Wrap a Monad in this if you want partials to

44+-- be looked for locally (or, when the main template

45+-- is at a URL, via HTTP), falling back to default data files.

46+newtype WithPartials m a = WithPartials { runWithPartials :: m a }

47+ deriving (Functor, Applicative, Monad)

48+

49+instance PandocMonad m => TemplateMonad (WithDefaultPartials m) where

50+ getPartial fp = WithDefaultPartials $

51+ UTF8.toText <$> readDataFile fp

52+

53+instance PandocMonad m => TemplateMonad (WithPartials m) where

54+ getPartial fp = WithPartials $ getTemplate fp

55+

56+-- | Retrieve text for a template.

57+getTemplate :: PandocMonad m => FilePath -> m Text

58+getTemplate tp = UTF8.toText <$>

59+ ((do surl <- stSourceURL <$> getCommonState

60+ -- we don't want to look for templates remotely

61+ -- unless the full URL is specified:

62+ modifyCommonState $ \st -> st{

63+ stSourceURL = Nothing }

64+ (bs, _) <- fetchItem $ T.pack tp

65+ modifyCommonState $ \st -> st{

66+ stSourceURL = surl }

67+ return bs)

68+ `catchError`

69+ (\e -> case e of

70+ PandocResourceNotFound _ ->

71+ readDataFile ("templates" </> tp)

72+ _ -> throwError e))

2973

3074-- | Get default template for the specified writer.

3175getDefaultTemplate :: PandocMonad m

@@ -55,4 +99,15 @@ getDefaultTemplate writer = do

5599 let fname = "templates" </> "default" <.> T.unpack format

56100 UTF8.toText <$> readDataFile fname

57101

58−

102+-- | Get and compile default template for the specified writer.

103+-- Raise an error on compilation failure.

104+compileDefaultTemplate :: PandocMonad m

105+ => Text

106+ -> m (Template Text)

107+compileDefaultTemplate writer = do

108+ res <- getDefaultTemplate writer >>=

109+ runWithDefaultPartials .

110+ compileTemplate ("templates/default." <> T.unpack writer)

111+ case res of

112+ Left e -> throwError $ PandocTemplateError (T.pack e)

113+ Right t -> return t