@@ 1,3 1,5 @@
+{-# LANGUAGE OverloadedStrings #-}
+-- | Utilities for rewriting URLs referenced via CSS properties.
module Data.CSS.Preprocessor.Assets(StyleAssets(..), URIRewriter) where
-- TODO Unit test!
@@ 5,6 7,7 @@ import Data.Text as Txt
import Network.URI
import qualified Data.CSS.Syntax.StyleSheet as CSS
import qualified Data.CSS.Syntax.Tokens as CSSTok
+import Data.List (nub, elem)
-- | Extracts referenced URLs from specified properties.
data StyleAssets = StyleAssets {
@@ 15,25 18,26 @@ data StyleAssets = StyleAssets {
}
instance CSS.StyleSheet StyleAssets where
- addRule (StyleAssets filterProps self) (CSS.StyleRule _ props _) =
- StyleAssets filterProps $ nub (
- self ++ [uri | (prop, val) <- props,
- prop `elem` filterProps,
+ addRule self (CSS.StyleRule _ props _) =
+ StyleAssets (filterProps self) $ nub (
+ assets self ++ [uri | (prop, val) <- props,
+ prop `elem` filterProps self,
CSSTok.Url text <- val,
Just uri <- [parseAbsoluteURI $ Txt.unpack text]]
)
-- | Substitutes in given URLs into a property value.
+rewritePropertyVal :: [(URI, URI)] -> [CSSTok.Token] -> [CSSTok.Token]
rewritePropertyVal rewrites (CSSTok.Url text:vals)
- | Just uri <- parseURIReference $ Txt.unpack text, Just rewrite <- uri `M.lookup` rewrites =
+ | Just uri <- parseURIReference $ Txt.unpack text, Just rewrite <- uri `lookup` rewrites =
CSSTok.Url (Txt.pack $ uriToString id rewrite "") : rewritePropertyVal rewrites vals
| otherwise = CSSTok.Url "" : rewritePropertyVal rewrites vals
rewritePropertyVal rewrites (val:vals) = val:rewritePropertyVal rewrites vals
rewritePropertyVal _ [] = []
-- | Substitutes in given URLs into the inner stylesheet being parsed.
-data URIRewriter s = URIRewriter (M.Map URI URI) s
+data URIRewriter s = URIRewriter [(URI, URI)] s
instance CSS.StyleSheet s => CSS.StyleSheet (URIRewriter s) where
setPriority p (URIRewriter r s) = URIRewriter r $ CSS.setPriority p s
addRule (URIRewriter r s) (CSS.StyleRule sel props psuedo) =
@@ 41,4 45,4 @@ instance CSS.StyleSheet s => CSS.StyleSheet (URIRewriter s) where
(prop, rewritePropertyVal r val) | (prop, val) <- props
] psuedo
addAtRule (URIRewriter r s) name toks =
- let (self', toks') = CSS.addAtRule s name toks in (URIRewriter r s, toks)
+ let (self', toks') = CSS.addAtRule s name toks in (URIRewriter r self', toks')