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
|
--------------------------------------------------------------------------------
-- | This module provides a declarative DSL in which the user can specify the
-- different rules used to run the compilers.
--
-- The convention is to just list all items in the 'Rules' monad, routes and
-- compilation rules.
--
-- A typical usage example would be:
--
-- > main = hakyll $ do
-- > match "posts/*" $ do
-- > route (setExtension "html")
-- > compile someCompiler
-- > match "css/*" $ do
-- > route idRoute
-- > compile compressCssCompiler
{-# LANGUAGE GeneralizedNewtypeDeriving #-}
{-# LANGUAGE OverloadedStrings #-}
module Hakyll.Core.Rules
( Rules
, match
, matchMetadata
, create
, version
, compile
, route
-- * Advanced usage
, preprocess
, Dependency (..)
, rulesExtraDependencies
) where
--------------------------------------------------------------------------------
import Control.Applicative ((<$>))
import Control.Monad.Reader (ask, local)
import Control.Monad.State (get, modify, put)
import Control.Monad.Trans (liftIO)
import Control.Monad.Writer (censor, tell)
import Data.Maybe (fromMaybe)
import Data.Monoid (mempty)
import qualified Data.Set as S
--------------------------------------------------------------------------------
import Data.Binary (Binary)
import Data.Typeable (Typeable)
--------------------------------------------------------------------------------
import Hakyll.Core.Compiler.Internal
import Hakyll.Core.Dependencies
import Hakyll.Core.Identifier
import Hakyll.Core.Identifier.Pattern
import Hakyll.Core.Item
import Hakyll.Core.Item.SomeItem
import Hakyll.Core.Metadata
import Hakyll.Core.Routes
import Hakyll.Core.Rules.Internal
import Hakyll.Core.Writable
--------------------------------------------------------------------------------
-- | Add a route
tellRoute :: Routes -> Rules ()
tellRoute route' = Rules $ tell $ RuleSet route' mempty mempty mempty
--------------------------------------------------------------------------------
-- | Add a number of compilers
tellCompilers :: [(Identifier, Compiler SomeItem)] -> Rules ()
tellCompilers compilers = Rules $ tell $ RuleSet mempty compilers mempty mempty
--------------------------------------------------------------------------------
-- | Add resources
tellResources :: [Identifier] -> Rules ()
tellResources resources' = Rules $ tell $
RuleSet mempty mempty (S.fromList resources') mempty
--------------------------------------------------------------------------------
-- | Add a pattern
tellPattern :: Pattern -> Rules ()
tellPattern pattern = Rules $ tell $ RuleSet mempty mempty mempty pattern
--------------------------------------------------------------------------------
flush :: Rules ()
flush = Rules $ do
mcompiler <- rulesCompiler <$> get
case mcompiler of
Nothing -> return ()
Just compiler -> do
matches' <- rulesMatches <$> ask
version' <- rulesVersion <$> ask
route' <- fromMaybe mempty . rulesRoute <$> get
-- The version is possibly not set correctly at this point (yet)
let ids = map (setVersion version') matches'
{-
ids <- case fromLiteral pattern of
Just id' -> return [setVersion version' id']
Nothing -> do
ids <- unRules $ getMatches pattern
unRules $ tellResources ids
return $ map (setVersion version') ids
-}
-- Create a fast pattern for routing that matches exactly the
-- compilers created in the block given to match
let fastPattern = fromList ids
-- Write out the compilers and routes
unRules $ tellRoute $ matchRoute fastPattern route'
unRules $ tellCompilers $ [(id', compiler) | id' <- ids]
put $ emptyRulesState
--------------------------------------------------------------------------------
matchInternal :: Pattern -> Rules [Identifier] -> Rules () -> Rules ()
matchInternal pattern getIDs rules = do
tellPattern pattern
flush
ids <- getIDs
tellResources ids
Rules $ local (setMatches ids) $ unRules $ rules >> flush
where
setMatches ids env = env {rulesMatches = ids}
--------------------------------------------------------------------------------
match :: Pattern -> Rules () -> Rules ()
match pattern = matchInternal pattern $ getMatches pattern
--------------------------------------------------------------------------------
matchMetadata :: Pattern -> (Metadata -> Bool) -> Rules () -> Rules ()
matchMetadata pattern metadataPred = matchInternal pattern $
map fst . filter (metadataPred . snd) <$> getAllMetadata pattern
--------------------------------------------------------------------------------
create :: [Identifier] -> Rules () -> Rules ()
create ids rules = do
flush
-- TODO Maybe check if the resources exist and call tellResources on that
Rules $ local setMatches $ unRules $ rules >> flush
where
setMatches env = env {rulesMatches = ids}
--------------------------------------------------------------------------------
version :: String -> Rules () -> Rules ()
version v rules = do
flush
Rules $ local setVersion' $ unRules $ rules >> flush
where
setVersion' env = env {rulesVersion = Just v}
--------------------------------------------------------------------------------
-- | Add a compilation rule to the rules.
--
-- This instructs all resources to be compiled using the given compiler.
compile :: (Binary a, Typeable a, Writable a) => Compiler (Item a) -> Rules ()
compile compiler = Rules $ modify $ \s ->
s {rulesCompiler = Just (fmap SomeItem compiler)}
--------------------------------------------------------------------------------
-- | Add a route.
--
-- This adds a route for all items matching the current pattern.
route :: Routes -> Rules ()
route route' = Rules $ modify $ \s -> s {rulesRoute = Just route'}
--------------------------------------------------------------------------------
-- | Execute an 'IO' action immediately while the rules are being evaluated.
-- This should be avoided if possible, but occasionally comes in useful.
preprocess :: IO a -> Rules a
preprocess = Rules . liftIO
--------------------------------------------------------------------------------
-- | Advanced usage: add extra dependencies to compilers. Basically this is
-- needed when you're doing unsafe tricky stuff in the rules monad, but you
-- still want correct builds.
--
-- A useful utility for this purpose is 'makePatternDependency'.
rulesExtraDependencies :: [Dependency] -> Rules a -> Rules a
rulesExtraDependencies deps rules =
-- Note that we add the dependencies seemingly twice here. However, this is
-- done so that 'rulesExtraDependencies' works both if we have something
-- like:
--
-- > match "*.css" $ rulesExtraDependencies [foo] $ ...
--
-- and something like:
--
-- > rulesExtraDependencies [foo] $ match "*.css" $ ...
--
-- (1) takes care of the latter and (2) of the former.
Rules $ censor fixRuleSet $ do
x <- unRules rules
fixCompiler
return x
where
-- (1) Adds the dependencies to the compilers we are yet to create
fixCompiler = modify $ \s -> case rulesCompiler s of
Nothing -> s
Just c -> s
{ rulesCompiler = Just $ compilerTellDependencies deps >> c
}
-- (2) Adds the dependencies to the compilers that are already in the ruleset
fixRuleSet ruleSet = ruleSet
{ rulesCompilers =
[ (i, compilerTellDependencies deps >> c)
| (i, c) <- rulesCompilers ruleSet
]
}
|
