@@ -2,7 +2,7 @@ module Text.XML.DOM.Parser.Combinators
2 ( -- * Generic combinators to traverse descendants
2 ( -- * Generic combinators to traverse descendants
3 traverseElems
3 traverseElems
4 , inFilteredTrav
4 , inFilteredTrav
5− -- * Using 'Buildable'
5+ -- * Using 'DomTraversable'
6 , inElemTrav
6 , inElemTrav
8 , inElemAll
8 , inElemAll
@@ -15,30 +15,46 @@ module Text.XML.DOM.Parser.Combinators
15 , ignoreElem
15 , ignoreElem
16 , ignoreEmpty
16 , ignoreEmpty
17 , ignoreBlank
17 , ignoreBlank
18+ -- * Getting current element's properties
21+ , getCurrentAttributes
22+ , getCurrentAttribute
23+ -- * Current element's checks
25+ -- * Parsing element's content
29+ -- * Parsing attributes
20−import Control.Lens
33+import Control.Lens
34+import Control.Monad.Except
21−import Control.Monad.Reader
35+import Control.Monad.Reader
22−import Data.Foldable as F
36+import Data.List.NonEmpty (NonEmpty(..))
23−import Data.List as L
37+import qualified Data.Map.Strict as M
24−import Data.List.NonEmpty (NonEmpty(..))
38+import Data.Monoid
39+import Data.Text (Text)
25−import Data.Text as T
40+import qualified Data.Text as T
26−import Data.Traversable
41+import Data.Traversable
27−import Text.XML
42+import Data.Typeable
28−import Text.XML.DOM.Parser.Buildable
44+import Text.XML
29−import Text.XML.DOM.Parser.Types
45+import Text.XML.DOM.Parser.Types
30−import Text.XML.Lens
46+import Text.XML.Lens
33−-- | Generic function to traverse arbitrary inner elements.
49+-- | Generic function to traverse arbitrary inner cursors.
34traverseElems
50traverseElems
35 :: (Monad m, Foldable g, Traversable f)
51 :: (Monad m, Foldable g, Traversable f)
36 => ([Element] -> DomParserT g m (f (DomPath, Element)))
52 => ([Element] -> DomParserT g m (f (DomPath, Element)))
37 -- ^ Takes list of current elements and returns container with
53 -- ^ Takes list of current elements and returns container with
38− -- pairs of subpath (relatively to current elements) and element
54+ -- pairs of subpath (relatively to current element) and element
39 -- to run parser in
55 -- to run parser in
40 -> DomParserT Identity m a
56 -> DomParserT Identity m a
41− -- ^ Parser to run for each element found in traversable 'f'
57+ -- ^ Parser will be runned for each element found in traversable
42 -> DomParserT g m (f a)
58 -> DomParserT g m (f a)
43traverseElems trav parser = do
59traverseElems trav parser = do
@@ -48,73 +64,68 @@ traverseElems trav parser = do
48 newpd = ParserData
64 newpd = ParserData
49 { _pdElements = Identity e
65 { _pdElements = Identity e
50 , _pdPath = pd ^. pdPath <> subpath }
66 , _pdPath = pd ^. pdPath <> subpath }
51− lift $ runReaderT parser newpd
67+ -- type of reader has been changed, local won't work here
68+ magnify (to $ const newpd) parser
53−-- | Traverses elements located in same path using filtering function
70+-- | Takes function filtering
54inFilteredTrav
71inFilteredTrav
55− :: (Monad m, Foldable g, Buildable f)
72+ :: (Monad m, Foldable g, DomTraversable f)
56 => ([Element] -> (DomPath, [Element]))
73 => ([Element] -> (DomPath, [Element]))
57− -- ^ Takes list of current elements and returns some descendants
74+ -- ^ Function returning some filtered elements with path suffixes which will
58− -- subset and path this descendants located at. Path is should be
75+ -- be appended to parser's state
59− -- same for all descendants and required for error message
60 -> DomParserT Identity m a
76 -> DomParserT Identity m a
61 -> DomParserT g m (f a)
77 -> DomParserT g m (f a)
62inFilteredTrav deeper = traverseElems trav
78inFilteredTrav deeper = traverseElems trav
64 trav e = do
80 trav e = do
65 let (path, elems) = deeper e
81 let (path, elems) = deeper e
66− case build elems of
82+ case buildDomTraversable elems of
67 Nothing -> throwParserError $ PENotFound . (<> path)
83 Nothing -> throwParserError $ PENotFound . (<> path)
68 Just tr -> return $ fmap (path,) tr
84 Just tr -> return $ fmap (path,) tr
70−-- | Runs parser arbitrary times, depending on 'Buildable' instance of
71−-- 'f'. For example if 'f' becomes 'NonEmpty' then 'inElemTrav' finds
72−-- @one or more@ elements matched by given 'ElemMatcher' and run
73−-- parser in each found element, then returns @NonEmpty a@ of results.
75− :: (Monad m, Foldable g, Buildable f)
87+ :: (Monad m, Foldable g, DomTraversable f)
76− => ElemMatcher -- ^ Tag(s) matcher to traverse in
88+ => Text
77 -> DomParserT Identity m a
89 -> DomParserT Identity m a
78 -> DomParserT g m (f a)
90 -> DomParserT g m (f a)
79inElemTrav n = inFilteredTrav deeper
91inElemTrav n = inFilteredTrav deeper
81− elemsFold = folded . nodes . folded . _Element . elMatch n
93+ deeper = ([n],) . toListOf (folded . nodes . folded . _Element . ell n)
82− deeper = (DomPath [_emShow n],) . toListOf elemsFold
84−-- | Runs parser inside first children element matched by macher
95+-- | Runs parser inside first children element with given name
86 :: (Monad m, Foldable g)
97 :: (Monad m, Foldable g)
87− => ElemMatcher
98+ => Text
88 -> DomParserT Identity m a
99 -> DomParserT Identity m a
89 -> DomParserT g m a
100 -> DomParserT g m a
90inElem n = fmap runIdentity . inElemTrav n
101inElem n = fmap runIdentity . inElemTrav n
93 :: (Monad m, Foldable g)
104 :: (Monad m, Foldable g)
94− => ElemMatcher
105+ => Text
95 -> DomParserT Identity m a
106 -> DomParserT Identity m a
96 -> DomParserT g m [a]
107 -> DomParserT g m [a]
97inElemAll = inElemTrav
108inElemAll = inElemTrav
100 :: (Monad m, Foldable g)
111 :: (Monad m, Foldable g)
101− => ElemMatcher
112+ => Text
102 -> DomParserT Identity m a
113 -> DomParserT Identity m a
103 -> DomParserT g m (Maybe a)
114 -> DomParserT g m (Maybe a)
104inElemMay = inElemTrav
115inElemMay = inElemTrav
107 :: (Monad m, Foldable g)
118 :: (Monad m, Foldable g)
108− => ElemMatcher
119+ => Text
109 -> DomParserT Identity m a
120 -> DomParserT Identity m a
110 -> DomParserT g m (NonEmpty a)
121 -> DomParserT g m (NonEmpty a)
111inElemNe = inElemTrav
122inElemNe = inElemTrav
113{- | Dive given parser's current tags set into the given path. The @divePath
124{- | Dive given parser's current tags set into the given path. The @divePath
114−["a", "b"]@ differs from @inElem "a" $ inElem "b"@. Namely the first variant
125+["a", "b"]@ differs from @inElem "a" . inElem "b"@. Namely the first variant
115will not fail if occured tag "a" which does not contains tag "b". This
126will not fail if occured tag "a" which does not contains tag "b". This
116behaviour is desireable when you dont want to parse whole XML and just want
127behaviour is desireable when you dont want to parse whole XML and just want
117−to pull tags located in some path. The other difference is in traversing inner
128+to pull tags in some path. The other difference is in traversing inner
118elements. Consider this code
129elements. Consider this code
@@ -132,31 +143,26 @@ which translates like: @a > b > c > fromDom@
132As you can see, inElem always takes first element and runs inner parser in this
143As you can see, inElem always takes first element and runs inner parser in this
133single element, unlike 'divePath' which runs inner parser @in all@ descendants
144single element, unlike 'divePath' which runs inner parser @in all@ descendants
134in given path.
145in given path.
136−Note also that 'divePath' takes parser parameterized by @[]@ not by
137−'Identity'. This because when you dive using some path you will get a
138−list of found elements and all these elements will be @current@ for
143 :: forall m g a
149 :: forall m g a
144 . (Monad m, Foldable g)
150 . (Monad m, Foldable g)
145− => [ElemMatcher]
151+ => [Text]
146 -> DomParserT [] m a
152 -> DomParserT [] m a
147 -> DomParserT g m a
153 -> DomParserT g m a
148divePath path = magnify $ to modElems
154divePath path = magnify $ to modElems
151 = over pdElements (toListOf $ folded . diver)
157 = over pdElements (toListOf $ folded . diver)
152− . over pdPath (<> DomPath (L.map _emShow path))
158+ . over pdPath (<> path)
153 diver :: Fold Element Element
159 diver :: Fold Element Element
154− diver = F.foldr (.) id $ L.map toDive path
160+ diver = foldr (.) id $ map toDive path
155− toDive n = nodes . folded . _Element . elMatch n
161+ toDive n = nodes . folded . _Element . ell n
158 :: (Monad m, Foldable g)
164 :: (Monad m, Foldable g)
159− => ElemMatcher
165+ => Text
160 -> DomParserT [] m a
166 -> DomParserT [] m a
161 -> DomParserT g m a
167 -> DomParserT g m a
162diveElem p = divePath [p]
168diveElem p = divePath [p]
@@ -183,7 +189,7 @@ ignoreEmpty
183 -> DomParserT Identity m (Maybe a)
189 -> DomParserT Identity m (Maybe a)
184ignoreEmpty = ignoreElem test
190ignoreEmpty = ignoreElem test
186− test e = L.null $ e ^. nodes
192+ test e = null $ e ^. nodes
188-- | If all current elements contains blank content, or contains nothing at all
194-- | If all current elements contains blank content, or contains nothing at all
189-- , then returns Nothing, else runs parser.
195-- , then returns Nothing, else runs parser.
@@ -197,6 +203,114 @@ ignoreBlank = ignoreElem test
198 elems = e ^.. nodes . folded . _Element
204 elems = e ^.. nodes . folded . _Element
199 cont = mconcat $ e ^.. nodes . folded . _Content
205 cont = mconcat $ e ^.. nodes . folded . _Content
200− in if | not $ L.null elems -> False
206+ in if | not $ null elems -> False
201 | T.null $ T.strip cont -> True
207 | T.null $ T.strip cont -> True
202 | otherwise -> False
208 | otherwise -> False
210+-- | Returns name of current element.
213+getCurrentName :: (Monad m) => DomParserT Identity m Text
214+getCurrentName = view $ pdElements . to runIdentity . localName
216+-- | If name of current tag differs from first argument throws 'PENotFound' with
217+-- tag name replaced in last path's segment. Useful for checking root
218+-- document's element name.
222+ -> DomParserT Identity m ()
223+checkCurrentName n = do
224+ cn <- getCurrentName
225+ unless (cn == n) $ do
227+ let pinit = if null p then [] else init p
228+ throwError $ ParserErrors [PENotFound $ pinit ++ [n]]
231+-- | Get current content. If current element contains no content or
232+-- have inner elements then Nothing returned
235+getCurrentContent :: (Monad m) => DomParserT Identity m (Maybe Text)
236+getCurrentContent = do
237+ nds <- view $ pdElements . to runIdentity . nodes
240+ els = nds ^.. folded . _Element
242+ conts = nds ^.. folded . _Content
244+ | not $ null els -> Nothing
245+ | null conts -> Nothing
246+ | otherwise -> Just $ mconcat conts
248+-- | Parses content inside current tag. It expects current element set
249+-- consists of exactly ONE element. If current element does not
250+-- contains content or have other elements as childs then throws error
253+ => (Text -> Either Text a)
254+ -- ^ Content parser, return error msg if value is not parsed
255+ -> DomParserT Identity m a
256+parseContent parse = getCurrentContent >>= \case
257+ Nothing -> throwParserError PEContentNotFound
258+ Just c -> case parse c of
259+ Left e -> throwParserError $ PEWrongFormat e
262+-- | If reader returns 'Nothing' then resulting function returns 'Left
269+ => (Text -> Maybe a)
270+ -- ^ Content or attribute reader
272+ -- ^ Content or attribute value
274+maybeReadContent f t = maybe (Left msg) Right $ f t
276+ msg = "Not readable " <> n <> ": " <> t
277+ n = T.pack $ show $ typeRep (Proxy :: Proxy a)
279+-- | Tries to read given text to value using 'Read'. Useful to use
280+-- with 'parseContent' and 'parseAttribute'
282+ :: (Read a, Typeable a)
285+readContent = maybeReadContent $ readMaybe . T.unpack . T.strip
287+-- | Retuns map of attributes of current element
290+getCurrentAttributes :: (Monad m) => DomParserT Identity m (M.Map Name Text)
291+getCurrentAttributes = view $ pdElements . to runIdentity . attrs
293+-- | Returns element with given name or 'Nothing'
296+getCurrentAttribute :: (Monad m) => Text -> DomParserT Identity m (Maybe Text)
297+getCurrentAttribute attrName'
298+ = preview $ pdElements . to runIdentity . attr attrName
300+ attrName = Name attrName' Nothing Nothing
302+-- | Parses attribute with given name, throws error if attribute is not found.
309+ -> (Text -> Either Text a)
310+ -- ^ Attribute content parser
311+ -> DomParserT Identity m a
312+parseAttribute attrName parser = getCurrentAttribute attrName >>= \case
313+ Nothing -> throwParserError $ PEAttributeNotFound attrName
314+ Just aval -> case parser aval of
315+ Left err -> throwParserError $ PEAttributeWrongFormat attrName err