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
|
{-# 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, URI(..), parseURI)
import Data.ByteString.Base64
import qualified Data.ByteString.Char8 as B
import Data.ByteString (ByteString)
import System.FilePath (takeExtension, 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', err, fetchItem')
import Text.Pandoc.MediaBag (MediaBag)
import Text.Pandoc.MIME (MimeType)
import Text.Pandoc.UTF8 (toString, fromString)
import Text.Pandoc.Options (WriterOptions(..))
isOk :: Char -> Bool
isOk c = isAscii c && isAlphaNum c
convertTag :: MediaBag -> Maybe String -> Tag String -> IO (Tag String)
convertTag media sourceURL t@(TagOpen tagname as)
| tagname `elem`
["img", "embed", "video", "input", "audio", "source", "track"] = 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 sourceURL (fromAttrib "type" t) y
let enc = "data:" ++ mime ++ ";base64," ++ toString (encode raw)
return (x, enc)
else return (x,y)
convertTag media sourceURL t@(TagOpen "script" as) =
case fromAttrib "src" t of
[] -> return t
src -> do
(raw, mime) <- getRaw media sourceURL (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 sourceURL t@(TagOpen "link" as) =
case fromAttrib "href" t of
[] -> return t
src -> do
(raw, mime) <- getRaw media sourceURL (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 String -> FilePath -> ByteString
-> IO ByteString
cssURLs media sourceURL 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 sourceURL "" url'
rest <- cssURLs media sourceURL 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
getRaw :: MediaBag -> Maybe String -> MimeType -> String
-> IO (ByteString, MimeType)
getRaw media sourceURL mimetype src = do
let ext = map toLower $ takeExtension src
fetchResult <- fetchItem' media sourceURL src
(raw, respMime) <- case fetchResult of
Left msg -> err 67 $ "Could not fetch " ++ src ++
"\n" ++ show msg
Right x -> return x
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
let cssSourceURL = case parseURI src of
Just u
| uriScheme u `elem` ["http:","https:"] ->
Just $ show u{ uriPath = "",
uriQuery = "",
uriFragment = "" }
_ -> Nothing
result <- if mime == "text/css"
then cssURLs media cssSourceURL (takeDirectory src) raw'
else return raw'
return (result, mime)
-- | Convert HTML into self-contained HTML, incorporating images,
-- scripts, and CSS using data: URIs.
makeSelfContained :: WriterOptions -> String -> IO String
makeSelfContained opts inp = do
let tags = parseTags inp
out' <- mapM (convertTag (writerMediaBag opts) (writerSourceURL opts)) tags
return $ renderTags' out'
|
