module Text.BlogLiterately.Diagrams
( diagramsXF, diagramsInlineXF
) where
import Control.Arrow
import Data.List (isPrefixOf)
import qualified Data.Map as M
import Safe (readMay, headDef)
import System.Directory (createDirectoryIfMissing)
import System.FilePath
import System.IO (stderr, hPutStrLn)
import Diagrams.Backend.Cairo
import Diagrams.Backend.Cairo.Internal
import Diagrams.Builder
import Diagrams.Prelude (R2, zeroV)
import Diagrams.TwoD.Size ( SizeSpec2D(Dims), mkSizeSpec )
import Text.BlogLiterately
import Text.Pandoc
diagramsXF :: Transform
diagramsXF = Transform (\bl -> Kleisli $ renderBlockDiagrams bl) (const True)
renderBlockDiagrams :: BlogLiterately -> Pandoc -> IO Pandoc
renderBlockDiagrams _ p = bottomUpM (renderBlockDiagram defs) p
where
defs = queryWith extractDiaDef p
diagramsInlineXF :: Transform
diagramsInlineXF = Transform (\bl -> Kleisli $ renderInlineDiagrams bl) (const True)
renderInlineDiagrams :: BlogLiterately -> Pandoc -> IO Pandoc
renderInlineDiagrams _ p = bottomUpM (renderInlineDiagram defs) p
where
defs = queryWith extractDiaDef p
extractDiaDef :: Block -> [String]
extractDiaDef (CodeBlock (_, as, _) s)
= [src | "dia-def" `elem` (maybe id (:) tag) as]
where
(tag, src) = unTag s
extractDiaDef b = []
diaDir = "diagrams"
renderDiagram :: [String]
-> String
-> Attr
-> IO (Either String FilePath)
renderDiagram decls expr attr@(ident, cls, fields) = do
createDirectoryIfMissing True diaDir
res <- buildDiagram
Cairo
(zeroV :: R2)
(CairoOptions "default.png" size PNG False)
decls
(expr ++ " {- " ++ show attr ++ " -}")
[]
["Diagrams.Backend.Cairo"]
(hashedRegenerate
(\hash opts -> opts { cairoFileName = mkFile hash })
diaDir
)
case res of
ParseErr err -> do
let errStr = "\nParse error:\n" ++ err
putErrLn errStr
return (Left errStr)
InterpErr ierr -> do
let errStr = "\nInterpreter error:\n" ++ ppInterpError ierr
putErrLn errStr
return (Left errStr)
Skipped hash -> return (Right $ mkFile hash)
OK hash (act,_) -> act >> return (Right $ mkFile hash)
where
size = mkSizeSpec
(lookup "width" fields >>= readMay)
(lookup "height" fields >>= readMay)
mkFile base = diaDir </> base <.> "png"
renderBlockDiagram :: [String] -> Block -> IO Block
renderBlockDiagram defs c@(CodeBlock attr@(_, cls, _) s)
| "dia-def" `elem` tags = return Null
| "dia" `elem` tags = do
res <- renderDiagram (src : defs) "pad 1.1 dia" attr
case res of
Left err -> return (CodeBlock attr (s ++ err))
Right file -> return $ Para [Image [] (file, "")]
| otherwise = return c
where
(tag, src) = unTag s
tags = (maybe id (:) tag) cls
renderBlockDiagram _ b = return b
renderInlineDiagram :: [String] -> Inline -> IO Inline
renderInlineDiagram defs c@(Code attr@(_, cls, _) expr)
| "dia" `elem` cls = do
res <- renderDiagram defs expr attr
case res of
Left err -> return (Code attr (expr ++ err))
Right file -> return $ Image [] (file, "")
| otherwise = return c
renderInlineDiagram _ i = return i
putErrLn :: String -> IO ()
putErrLn = hPutStrLn stderr