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
|
{-# LANGUAGE OverloadedStrings #-}
{-
Copyright (C) 2011-2014 John MacFarlane <jgm@berkeley.edu>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
-}
{- |
Module : Text.Pandoc.SelfContained
Copyright : Copyright (C) 2011-2014 John MacFarlane
License : GNU GPL, version 2 or above
Maintainer : John MacFarlane <jgm@berkeley.edu>
Stability : alpha
Portability : portable
Functions for converting an HTML file into one that can be viewed
offline, by incorporating linked images, CSS, and scripts into
the HTML using data URIs.
-}
module Text.Pandoc.SelfContained ( makeSelfContained ) where
import Text.HTML.TagSoup
import Network.URI (isURI, escapeURIString)
import Data.ByteString.Base64
import qualified Data.ByteString.Char8 as B
import qualified Data.ByteString as BS
import Data.ByteString (ByteString)
import System.FilePath (takeExtension, dropExtension, takeDirectory, (</>))
import Data.Char (toLower, isAscii, isAlphaNum)
import Codec.Compression.GZip as Gzip
import qualified Data.ByteString.Lazy as L
import Text.Pandoc.Shared (renderTags', openURL, readDataFile, err, MediaBag)
import Text.Pandoc.UTF8 (toString, fromString)
import Text.Pandoc.MIME (getMimeType)
import System.Directory (doesFileExist)
import qualified Data.Map as M
isOk :: Char -> Bool
isOk c = isAscii c && isAlphaNum c
convertTag :: MediaBag -> Maybe FilePath -> Tag String -> IO (Tag String)
convertTag media userdata t@(TagOpen tagname as)
| tagname `elem` ["img", "embed", "video", "input", "audio", "source"] = do
as' <- mapM processAttribute as
return $ TagOpen tagname as'
where processAttribute (x,y) =
if x == "src" || x == "href" || x == "poster"
then do
(raw, mime) <- getRaw media userdata (fromAttrib "type" t) y
let enc = "data:" ++ mime ++ ";base64," ++ toString (encode raw)
return (x, enc)
else return (x,y)
convertTag media userdata t@(TagOpen "script" as) =
case fromAttrib "src" t of
[] -> return t
src -> do
(raw, mime) <- getRaw media userdata (fromAttrib "type" t) src
let enc = "data:" ++ mime ++ "," ++ escapeURIString isOk (toString raw)
return $ TagOpen "script" (("src",enc) : [(x,y) | (x,y) <- as, x /= "src"])
convertTag media userdata t@(TagOpen "link" as) =
case fromAttrib "href" t of
[] -> return t
src -> do
(raw, mime) <- getRaw media userdata (fromAttrib "type" t) src
let enc = "data:" ++ mime ++ "," ++ escapeURIString isOk (toString raw)
return $ TagOpen "link" (("href",enc) : [(x,y) | (x,y) <- as, x /= "href"])
convertTag _ _ t = return t
-- NOTE: This is really crude, it doesn't respect CSS comments.
cssURLs :: MediaBag -> Maybe FilePath -> FilePath -> ByteString
-> IO ByteString
cssURLs media userdata d orig =
case B.breakSubstring "url(" orig of
(x,y) | B.null y -> return orig
| otherwise -> do
let (u,v) = B.breakSubstring ")" $ B.drop 4 y
let url = toString
$ case B.take 1 u of
"\"" -> B.takeWhile (/='"') $ B.drop 1 u
"'" -> B.takeWhile (/='\'') $ B.drop 1 u
_ -> u
let url' = if isURI url
then url
else d </> url
(raw, mime) <- getRaw media userdata "" url'
rest <- cssURLs media userdata d v
let enc = "data:" `B.append` fromString mime `B.append`
";base64," `B.append` (encode raw)
return $ x `B.append` "url(" `B.append` enc `B.append` rest
getItem :: MediaBag -> Maybe FilePath -> String
-> IO (ByteString, Maybe String)
getItem media userdata f =
if isURI f
then openURL f >>= either handleErr return
else do
-- strip off trailing query or fragment part, if relative URL.
-- this is needed for things like cmunrm.eot?#iefix,
-- which is used to get old versions of IE to work with web fonts.
let f' = takeWhile (\c -> c /= '?' && c /= '#') f
let mime = case takeExtension f' of
".gz" -> getMimeType $ dropExtension f'
x -> getMimeType x
exists <- doesFileExist f'
cont <- if exists
then B.readFile f'
else case M.lookup f media of
Just bs -> return $ BS.concat $ L.toChunks bs
Nothing -> readDataFile userdata f'
return (cont, mime)
where handleErr e = err 61 $ "Failed to retrieve " ++ f ++ "\n" ++ show e
getRaw :: MediaBag -> Maybe FilePath -> String -> String
-> IO (ByteString, String)
getRaw media userdata mimetype src = do
let ext = map toLower $ takeExtension src
(raw, respMime) <- getItem media userdata src
let raw' = if ext == ".gz"
then B.concat $ L.toChunks $ Gzip.decompress $ L.fromChunks
$ [raw]
else raw
let mime = case (mimetype, respMime) of
("",Nothing) -> error
$ "Could not determine mime type for `" ++ src ++ "'"
(x, Nothing) -> x
(_, Just x ) -> x
result <- if mime == "text/css"
then cssURLs media userdata (takeDirectory src) raw'
else return raw'
return (result, mime)
-- | Convert HTML into self-contained HTML, incorporating images,
-- scripts, and CSS using data: URIs. Items specified using absolute
-- URLs will be downloaded; those specified using relative URLs will
-- be sought first relative to the working directory, then in the
-- media bag, then relative
-- to the user data directory (if the first parameter is 'Just'
-- a directory), and finally relative to pandoc's default data
-- directory.
makeSelfContained :: MediaBag -> Maybe FilePath -> String -> IO String
makeSelfContained media userdata inp = do
let tags = parseTags inp
out' <- mapM (convertTag media userdata) tags
return $ renderTags' out'
|
