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module TagSoup.Sample where
import Text.HTML.TagSoup
import Control.Exception
import Control.Monad
import Data.List
import System.Process
import System.Directory
import System.Exit
import System.IO
import Data.Functor
import Prelude
openItem :: String -> IO String
openItem url
| not $ "http://" `isPrefixOf` url || "https://" `isPrefixOf` url =
readFile url
openItem url = bracket
(openTempFile "." "tagsoup.tmp")
(\(file,hndl) -> removeFile file)
$ \(file,hndl) -> do
hClose hndl
putStrLn $ "Downloading: " ++ url
res <- system $ "wget " ++ url ++ " -O " ++ file
when (res /= ExitSuccess) $ error $ "Failed to download using wget: " ++ url
src <- readFile file
length src `seq` return src
grab :: String -> IO ()
grab x = openItem x >>= putStr
parse :: String -> IO ()
parse x = openItem x >>= putStr . show2 . parseTags
where
show2 [] = "[]"
show2 xs = "[" ++ concat (intersperseNotBroken "\n," $ map show xs) ++ "\n]\n"
-- the standard intersperse has a strictness bug which sucks!
intersperseNotBroken :: a -> [a] -> [a]
intersperseNotBroken _ [] = []
intersperseNotBroken sep (x:xs) = x : is xs
where
is [] = []
is (y:ys) = sep : y : is ys
{-
<li id="lastmod"> This page was last modified on 9 September 2013, at 22:38.</li>
-}
haskellLastModifiedDateTime :: IO ()
haskellLastModifiedDateTime = do
src <- openItem "http://wiki.haskell.org/Haskell"
let lastModifiedDateTime = fromFooter $ parseTags src
putStrLn $ "wiki.haskell.org was last modified on " ++ lastModifiedDateTime
where fromFooter = unwords . drop 6 . words . innerText . take 2 . dropWhile (~/= "<li id=lastmod>")
googleTechNews :: IO ()
googleTechNews = do
tags <- fmap parseTags $ openItem "http://news.google.com/?ned=us&topic=t"
let links = [ ascii name ++ " <" ++ maybe "unknown" shortUrl (lookup "href" atts) ++ ">"
| TagOpen "h2" [("class","title")]:TagText spaces:TagOpen "a" atts:TagText name:_ <- tails tags]
putStr $ unlines links
where
shortUrl x | "http://" `isPrefixOf` x = shortUrl $ drop 7 x
| "www." `isPrefixOf` x = shortUrl $ drop 4 x
| otherwise = takeWhile (/= '/') x
ascii ('\226':'\128':'\147':xs) = '-' : ascii xs
ascii ('\194':'\163':xs) = "#GBP " ++ ascii xs
ascii (x:xs) = x : ascii xs
ascii [] = []
spjPapers :: IO ()
spjPapers = do
tags <- parseTags <$> openItem "http://research.microsoft.com/en-us/people/simonpj/"
let links = map f $ sections (~== "<A>") $
takeWhile (~/= "<a name=haskell>") $
drop 5 $ dropWhile (~/= "<a name=current>") tags
putStr $ unlines links
where
f :: [Tag String] -> String
f = dequote . unwords . words . fromTagText . head . filter isTagText
dequote ('\"':xs) | last xs == '\"' = init xs
dequote x = x
ndmPapers :: IO ()
ndmPapers = do
tags <- parseTags <$> openItem "http://community.haskell.org/~ndm/downloads/"
let papers = map f $ sections (~== "<li class=paper>") tags
putStr $ unlines papers
where
f :: [Tag String] -> String
f xs = fromTagText (xs !! 2)
currentTime :: IO ()
currentTime = do
tags <- parseTags <$> openItem "http://www.timeanddate.com/worldclock/uk/london"
let time = fromTagText (dropWhile (~/= "<span id=ct>") tags !! 1)
putStrLn time
type Section = String
data Package = Package {name :: String, desc :: String, href :: String}
deriving Show
hackage :: IO [(Section,[Package])]
hackage = do
tags <- fmap parseTags $ openItem "http://hackage.haskell.org/packages/archive/pkg-list.html"
return $ map parseSect $ partitions (~== "<h3>") tags
where
parseSect xs = (nam, packs)
where
nam = fromTagText $ xs !! 2
packs = map parsePackage $ partitions (~== "<li>") xs
parsePackage xs =
Package
(fromTagText $ xs !! 2)
(drop 2 $ dropWhile (/= ':') $ fromTagText $ xs !! 4)
(fromAttrib "href" $ xs !! 1)
-- rssCreators Example: prints names of story contributors on
-- sequence.complete.org. This content is RSS (not HTML), and the selected
-- tag uses a different XML namespace "dc:creator".
rssCreators :: IO ()
rssCreators = do
tags <- fmap parseTags $ openItem "http://sequence.complete.org/node/feed"
putStrLn $ unlines $ map names $ partitions (~== "<dc:creator>") tags
where names xs = fromTagText $ xs !! 1
validate :: String -> IO ()
validate x = putStr . unlines . g . f . parseTagsOptions opts =<< openItem x
where
opts = parseOptions{optTagPosition=True, optTagWarning=True}
f :: [Tag String] -> [String]
f (TagPosition row col:TagWarning warn:rest) =
("Warning (" ++ show row ++ "," ++ show col ++ "): " ++ warn) : f rest
f (TagWarning warn:rest) =
("Warning (?,?): " ++ warn) : f rest
f (_:rest) = f rest
f [] = []
g xs = xs ++ [if n == 0 then "Success, no warnings"
else "Failed, " ++ show n ++ " warning" ++ ['s'|n>1]]
where n = length xs
-- | Parse a table
parseTable:: [[[String]]]
parseTable = do
let tags = parseTags tableExample
parseRow :: [Tag String] -> [String]
parseRow = map (innerText . takeWhile (~/="</td>")) . sections (~== "<td>")
dd = map (parseRow . takeWhile (~/= "</tr>")) . sections (~== "<tr>") $ tags
return dd
where
-- | Example from https://www.w3schools.com/html/html_tables.asp
tableExample =
"<table> \n\
\ <tr> \n\
\ <th>Company</th> \n\
\ <th>Contact</th> \n\
\ <th>Country</th> \n\
\ </tr> \n\
\ <tr> \n\
\ <td>Alfreds Futterkiste</td> \n\
\ <td>Maria Anders</td> \n\
\ <td>Germany</td> \n\
\ </tr> \n\
\ <tr> \n\
\ <td>Centro comercial Moctezuma</td> \n\
\ <td>Francisco Chang</td> \n\
\ <td>Mexico</td> \n\
\ </tr> \n\
\ <tr> \n\
\ <td>Ernst Handel</td> \n\
\ <td>Roland Mendel</td> \n\
\ <td>Austria</td> \n\
\ </tr> \n\
\ <tr> \n\
\ <td>Island Trading</td> \n\
\ <td>Helen Bennett</td> \n\
\ <td>UK</td> \n\
\ </tr> \n\
\ <tr> \n\
\ <td>Laughing Bacchus Winecellars</td> \n\
\ <td>Yoshi Tannamuri</td> \n\
\ <td>Canada</td> \n\
\ </tr> \n\
\ <tr> \n\
\ <td>Magazzini Alimentari Riuniti</td> \n\
\ <td>Giovanni Rovelli</td> \n\
\ <td>Italy</td> \n\
\ </tr> \n\
\ </table>"
|
