forked from lymar/hastache
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Hastache.hs
474 lines (418 loc) · 15.3 KB
/
Hastache.hs
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
{-# LANGUAGE ExistentialQuantification, FlexibleInstances,
IncoherentInstances #-}
-- Module: Text.Hastache
-- Copyright: Sergey S Lymar (c) 2011
-- License: BSD3
-- Maintainer: Sergey S Lymar <sergey.lymar@gmail.com>
-- Stability: experimental
-- Portability: portable
--
-- Haskell implementation of Mustache templates
{- | Haskell implementation of Mustache templates
See homepage for examples of usage: <http://github.com/lymar/hastache>
Simplest example:
@
import Text.Hastache
import Text.Hastache.Context
import qualified Data.ByteString.Lazy as LZ
main = do
res <- hastacheStr defaultConfig (encodeStr template)
(mkStrContext context)
LZ.putStrLn res
where
template = \"Hello, {{name}}!\\n\\nYou have {{unread}} unread messages.\"
context \"name\" = MuVariable \"Haskell\"
context \"unread\" = MuVariable (100 :: Int)
@
Result:
@
Hello, Haskell!
You have 100 unread messages.
@
Using Generics:
@
import Text.Hastache
import Text.Hastache.Context
import qualified Data.ByteString.Lazy as LZ
import Data.Data
import Data.Generics
data Info = Info {
name :: String,
unread :: Int
} deriving (Data, Typeable)
main = do
res <- hastacheStr defaultConfig (encodeStr template)
(mkGenericContext inf)
LZ.putStrLn res
where
template = \"Hello, {{name}}!\\n\\nYou have {{unread}} unread messages.\"
inf = Info \"Haskell\" 100
@
-}
module Text.Hastache (
hastacheStr
, hastacheFile
, hastacheStrBuilder
, hastacheFileBuilder
, MuContext
, MuType(..)
, MuConfig(..)
, MuVar(..)
, htmlEscape
, emptyEscape
, defaultConfig
, encodeStr
, encodeStrLBS
, decodeStr
, decodeStrLBS
) where
import Control.Monad (guard, when)
import Control.Monad.Reader (ask, runReaderT, MonadReader, ReaderT)
import Control.Monad.Trans (lift, liftIO, MonadIO)
import Data.ByteString hiding (map, foldl1)
import Data.Char (ord)
import Data.Int
import Data.IORef
import Data.Maybe (isJust)
import Data.Monoid (mappend, mempty)
import Data.Word
import Prelude hiding (putStrLn, readFile, length, drop, tail, dropWhile, elem,
head, last, reverse, take, span)
import System.Directory (doesFileExist)
import System.FilePath (combine)
import qualified Blaze.ByteString.Builder as BSB
import qualified Codec.Binary.UTF8.String as SU
import qualified Data.ByteString.Lazy as LZ
import qualified Data.List as List
import qualified Data.Text as Text
import qualified Data.Text.Lazy as LText
(~>) :: a -> (a -> b) -> b
x ~> f = f $ x
infixl 9 ~>
-- | Data for Hastache variable
type MuContext m =
ByteString -- ^ Variable name
-> MuType m -- ^ Value
class Show a => MuVar a where
toLByteString :: a -> LZ.ByteString
instance MuVar ByteString where
toLByteString = toLBS
instance MuVar LZ.ByteString where
toLByteString = id
withShowToLBS a = show a ~> encodeStr ~> toLBS
instance MuVar Integer where toLByteString = withShowToLBS
instance MuVar Int where toLByteString = withShowToLBS
instance MuVar Float where toLByteString = withShowToLBS
instance MuVar Double where toLByteString = withShowToLBS
instance MuVar Int8 where toLByteString = withShowToLBS
instance MuVar Int16 where toLByteString = withShowToLBS
instance MuVar Int32 where toLByteString = withShowToLBS
instance MuVar Int64 where toLByteString = withShowToLBS
instance MuVar Word where toLByteString = withShowToLBS
instance MuVar Word8 where toLByteString = withShowToLBS
instance MuVar Word16 where toLByteString = withShowToLBS
instance MuVar Word32 where toLByteString = withShowToLBS
instance MuVar Word64 where toLByteString = withShowToLBS
instance MuVar Text.Text where
toLByteString t = Text.unpack t ~> encodeStr ~> toLBS
instance MuVar LText.Text where
toLByteString t = LText.unpack t ~> encodeStr ~> toLBS
instance MuVar Char where
toLByteString a = (a : "") ~> encodeStr ~> toLBS
instance MuVar a => MuVar [a] where
toLByteString a = (toLByteString '[') <+> cnvLst <+> (toLByteString ']')
where
cnvLst = (map toLByteString a) ~>
(LZ.intercalate (toLByteString ','))
(<+>) = LZ.append
instance MuVar [Char] where
toLByteString k = k ~> encodeStr ~> toLBS
data MuType m =
forall a. MuVar a => MuVariable a |
MuList [MuContext m] |
MuBool Bool |
forall a. MuVar a => MuLambda (ByteString -> a) |
forall a. MuVar a => MuLambdaM (ByteString -> m a) |
MuNothing
instance Show (MuType m) where
show (MuVariable a) = "MuVariable " ++ show a
show (MuList _) = "MuList [..]"
show (MuBool v) = "MuBool " ++ show v
show (MuLambda _) = "MuLambda <..>"
show (MuLambdaM _) = "MuLambdaM <..>"
show MuNothing = "MuNothing"
data MuConfig = MuConfig {
muEscapeFunc :: LZ.ByteString -> LZ.ByteString,
-- ^ Escape function ('htmlEscape', 'emptyEscape' etc.)
muTemplateFileDir :: Maybe FilePath,
-- ^ Directory for search partial templates ({{> templateName}})
muTemplateFileExt :: Maybe String
-- ^ Partial template files extension
}
-- | Convert String to UTF-8 Bytestring
encodeStr :: String -> ByteString
encodeStr = pack . SU.encode
-- | Convert String to UTF-8 Lazy Bytestring
encodeStrLBS :: String -> LZ.ByteString
encodeStrLBS = LZ.pack . SU.encode
-- | Convert UTF-8 Bytestring to String
decodeStr :: ByteString -> String
decodeStr = SU.decode . unpack
-- | Convert UTF-8 Lazy Bytestring to String
decodeStrLBS :: LZ.ByteString -> String
decodeStrLBS = SU.decode . LZ.unpack
ord8 :: Char -> Word8
ord8 = fromIntegral . ord
isMuNothing MuNothing = True
isMuNothing _ = False
-- | Escape HTML symbols
htmlEscape :: LZ.ByteString -> LZ.ByteString
htmlEscape str = LZ.unpack str ~> proc ~> LZ.pack
where
proc :: [Word8] -> [Word8]
proc (h:t)
| h == ord8 '&' = stp "&" t
| h == ord8 '\\'= stp "\" t
| h == ord8 '"' = stp """ t
| h == ord8 '\''= stp "'" t
| h == ord8 '<' = stp "<" t
| h == ord8 '>' = stp ">" t
| otherwise = h : (proc t)
proc [] = []
stp a t = (map ord8 a) ++ (proc t)
-- | No escape
emptyEscape :: LZ.ByteString -> LZ.ByteString
emptyEscape = id
{- | Default config: HTML escape function, current directory as
template directory, template file extension not specified -}
defaultConfig :: MuConfig
defaultConfig = MuConfig {
muEscapeFunc = htmlEscape,
muTemplateFileDir = Nothing,
muTemplateFileExt = Nothing
}
defOTag = encodeStr "{{"
defCTag = encodeStr "}}"
unquoteCTag = encodeStr "}}}"
findBlock ::
ByteString
-> ByteString
-> ByteString
-> Maybe (ByteString, Word8, ByteString, ByteString)
findBlock str otag ctag = do
guard (length fnd > (length otag))
Just (pre, symb, inTag, afterClose)
where
(pre, fnd) = breakSubstring otag str
symb = index fnd (length otag)
(inTag, afterClose)
-- test for unescape ( {{{some}}} )
| symb == ord8 '{' && ctag == defCTag =
breakSubstring unquoteCTag fnd ~> \(a,b) ->
(drop (length otag) a, drop 3 b)
| otherwise = breakSubstring ctag fnd ~> \(a,b) ->
(drop (length otag) a, drop (length ctag) b)
toLBS :: ByteString -> LZ.ByteString
toLBS v = LZ.fromChunks [v]
readVar [] _ = LZ.empty
readVar (context:parentCtx) name =
case context name of
MuVariable a -> toLByteString a
MuBool a -> show a ~> encodeStr ~> toLBS
MuNothing -> readVar parentCtx name
_ -> LZ.empty
findCloseSection ::
ByteString
-> ByteString
-> ByteString
-> ByteString
-> Maybe (ByteString, ByteString)
findCloseSection str name otag ctag = do
guard (length after > 0)
Just (before, drop (length close) after)
where
close = foldl1 append [otag, encodeStr "/", name, ctag]
(before, after) = breakSubstring close str
trimCharsTest :: Word8 -> Bool
trimCharsTest = (`elem` (encodeStr " \t"))
trimAll :: ByteString -> ByteString
trimAll str = span trimCharsTest str ~> snd ~> spanEnd trimCharsTest ~> fst
addRes :: MonadIO m => LZ.ByteString -> ReaderT (IORef BSB.Builder) m ()
addRes str = do
rf <- ask
b <- readIORef rf ~> liftIO
let l = mappend b (BSB.fromLazyByteString str)
writeIORef rf l ~> liftIO
return ()
addResBS :: MonadIO m => ByteString -> ReaderT (IORef BSB.Builder) m ()
addResBS str = toLBS str ~> addRes
addResLZ :: MonadIO m => LZ.ByteString -> ReaderT (IORef BSB.Builder) m ()
addResLZ = addRes
processBlock :: MonadIO m =>
ByteString
-> [ByteString -> MuType m]
-> ByteString
-> ByteString
-> MuConfig
-> ReaderT (IORef BSB.Builder) m ()
processBlock str contexts otag ctag conf = do
case findBlock str otag ctag of
Just (pre, symb, inTag, afterClose) -> do
addResBS pre
renderBlock contexts symb inTag afterClose
otag ctag conf
Nothing -> do
addResBS str
return ()
renderBlock:: MonadIO m =>
[ByteString -> MuType m]
-> Word8
-> ByteString
-> ByteString
-> ByteString
-> ByteString
-> MuConfig
-> ReaderT (IORef BSB.Builder) m ()
renderBlock contexts symb inTag afterClose otag ctag conf
-- comment
| symb == ord8 '!' = next afterClose
-- unescape variable
| symb == ord8 '&' || (symb == ord8 '{' && otag == defOTag) = do
readVar contexts (tail inTag ~> trimAll) ~> addResLZ
next afterClose
-- section. inverted section
| symb == ord8 '#' || symb == ord8 '^' =
let normalSection = symb == ord8 '#' in do
case findCloseSection afterClose (tail inTag) otag ctag of
Nothing -> next afterClose
Just (sectionContent', afterSection') ->
let
dropNL str =
if (length str) > 0 && (head str) == ord8 '\n'
then tail str
else str
sectionContent = dropNL sectionContent'
afterSection =
if ord8 '\n' `elem` sectionContent
then dropNL afterSection'
else afterSection'
tlInTag = tail inTag
readContext = map ($ tlInTag) contexts
~> List.find (not . isMuNothing)
in do
case readContext of
Just (MuList []) ->
if normalSection then do next afterSection
else do
processBlock sectionContent
contexts otag ctag conf
next afterSection
Just (MuList b) ->
if normalSection then do
mapM_ (\c -> processBlock sectionContent
(c:contexts) otag ctag conf) b
next afterSection
else do next afterSection
Just (MuBool True) ->
if normalSection then do
processBlock sectionContent
contexts otag ctag conf
next afterSection
else do next afterSection
Just (MuBool False) ->
if normalSection then do next afterSection
else do
processBlock sectionContent
contexts otag ctag conf
next afterSection
Just (MuLambda func) ->
if normalSection then do
func sectionContent ~> toLByteString ~> addResLZ
next afterSection
else do next afterSection
Just (MuLambdaM func) ->
if normalSection then do
res <- lift (func sectionContent)
toLByteString res ~> addResLZ
next afterSection
else do next afterSection
_ -> next afterSection
-- set delimiter
| symb == ord8 '=' =
let
lenInTag = length inTag
delimitersCommand = take (lenInTag - 1) inTag ~> drop 1
getDelimiter = do
guard (lenInTag > 4)
guard ((index inTag $ lenInTag - 1) == ord8 '=')
[newOTag,newCTag] <- Just $ split (ord8 ' ')
delimitersCommand
Just (newOTag, newCTag)
in do
case getDelimiter of
Nothing -> next afterClose
Just (newOTag, newCTag) ->
processBlock (trim' afterClose) contexts
newOTag newCTag conf
-- partials
| symb == ord8 '>' =
let
fileName' = tail inTag ~> trimAll
fileName'' = case muTemplateFileExt conf of
Nothing -> fileName'
Just ext -> fileName' `append` (encodeStr ext)
fileName = decodeStr fileName''
fullFileName = case muTemplateFileDir conf of
Nothing -> fileName
Just path -> combine path fileName
in do
fe <- liftIO $ doesFileExist fullFileName
when fe $ do
cnt <- liftIO $ readFile fullFileName
next cnt
next (trim' afterClose)
-- variable
| otherwise = do
readVar contexts (trimAll inTag) ~> muEscapeFunc conf ~> addResLZ
next afterClose
where
next t = processBlock t contexts otag ctag conf
trim' content =
dropWhile trimCharsTest content
~> \t -> if (length t > 0 && head t == ord8 '\n')
then tail t else content
-- | Render Hastache template from ByteString
hastacheStr :: (MonadIO m) =>
MuConfig -- ^ Configuration
-> ByteString -- ^ Template
-> MuContext m -- ^ Context
-> m LZ.ByteString
hastacheStr conf str context =
hastacheStrBuilder conf str context >>= return . BSB.toLazyByteString
-- | Render Hastache template from file
hastacheFile :: (MonadIO m) =>
MuConfig -- ^ Configuration
-> FilePath -- ^ Template file name
-> MuContext m -- ^ Context
-> m LZ.ByteString
hastacheFile conf file_name context =
hastacheFileBuilder conf file_name context >>= return . BSB.toLazyByteString
-- | Render Hastache template from ByteString
hastacheStrBuilder :: (MonadIO m) =>
MuConfig -- ^ Configuration
-> ByteString -- ^ Template
-> MuContext m -- ^ Context
-> m BSB.Builder
hastacheStrBuilder conf str context = do
rf <- newIORef mempty ~> liftIO
runReaderT (processBlock str [context] defOTag defCTag conf) rf
readIORef rf ~> liftIO
-- | Render Hastache template from file
hastacheFileBuilder :: (MonadIO m) =>
MuConfig -- ^ Configuration
-> FilePath -- ^ Template file name
-> MuContext m -- ^ Context
-> m BSB.Builder
hastacheFileBuilder conf file_name context = do
str <- readFile file_name ~> liftIO
hastacheStrBuilder conf str context