This commit is contained in:
Joe Nelson
2015-11-14 17:52:05 -08:00
27 changed files with 1820 additions and 1670 deletions
+12 -64
View File
@@ -1,48 +1,27 @@
module PostgREST.Parsers
( parseGetRequest
)
-- ( parseGetRequest
-- )
where
import Control.Applicative hiding ((<$>))
--lines needed for ghc 7.8
import Data.Functor ((<$>))
import Data.Traversable (traverse)
import Control.Monad (join)
import Data.List (delete, find)
import Data.Maybe
import Data.Monoid
import Data.String.Conversions (cs)
import Data.Text (Text)
import Data.Tree
import Network.Wai (Request, pathInfo, queryString)
import PostgREST.Types
import Text.ParserCombinators.Parsec hiding (many, (<|>))
parseGetRequest :: Request -> Either ParseError ApiRequest
parseGetRequest httpRequest =
foldr addFilter <$> (addOrder <$> apiRequest <*> ord) <*> flts
where
apiRequest = parse (pRequestSelect rootTableName) ("failed to parse select parameter <<"++selectStr++">>") $ cs selectStr
addOrder (Node r f) o = Node r{order=o} f
flts = mapM pRequestFilter whereFilters
rootTableName = cs $ head $ pathInfo httpRequest -- TODO unsafe head
qString = [(cs k, cs <$> v)|(k,v) <- queryString httpRequest]
orderStr = join $ lookup "order" qString
ord = traverse (parse pOrder ("failed to parse order parameter <<"++fromMaybe "" orderStr++">>")) orderStr
selectStr = fromMaybe "*" $ fromMaybe (Just "*") $ lookup "select" qString --in case the parametre is missing or empty we default to *
whereFilters = [ (k, fromJust v) | (k,v) <- qString, k `notElem` ["select", "order"], isJust v ]
import PostgREST.PgQuery (operators)
pRequestSelect :: Text -> Parser ApiRequest
pRequestSelect rootNodeName = do
fieldTree <- pFieldForest
return $ foldr treeEntry (Node (Select rootNodeName [] [] [] Nothing Nothing) []) fieldTree
return $ foldr treeEntry (Node (Select [] [rootNodeName] [] Nothing, (rootNodeName, Nothing)) []) fieldTree
where
treeEntry :: Tree SelectItem -> ApiRequest -> ApiRequest
treeEntry (Node fld@((fn, _),_) fldForest) (Node rNode rForest) =
treeEntry (Node fld@((fn, _),_) fldForest) (Node (q, i) rForest) =
case fldForest of
[] -> Node (rNode {fields=fld:fields rNode}) rForest
_ -> Node rNode (foldr treeEntry (Node (Select fn [] [] [] Nothing Nothing) []) fldForest:rForest)
[] -> Node (q {select=fld:select q}, i) rForest
_ -> Node (q, i) (foldr treeEntry (Node (Select [] [fn] [] Nothing, (fn, Nothing)) []) fldForest:rForest)
pRequestFilter :: (String, String) -> Either ParseError (Path, Filter)
pRequestFilter (k, v) = (,) <$> path <*> (Filter <$> fld <*> op <*> val)
@@ -54,21 +33,6 @@ pRequestFilter (k, v) = (,) <$> path <*> (Filter <$> fld <*> op <*> val)
op = fst <$> opVal
val = snd <$> opVal
addFilter :: (Path, Filter) -> ApiRequest -> ApiRequest
addFilter ([], flt) (Node rn@(Select {filters=flts}) forest) = Node (rn {filters=flt:flts}) forest
addFilter (path, flt) (Node rn forest) =
case targetNode of
Nothing -> Node rn forest -- the filter is silenty dropped in the Request does not contain the required path
Just tn -> Node rn (addFilter (remainingPath, flt) tn:restForest)
where
targetNodeName:remainingPath = path
(targetNode,restForest) = splitForest targetNodeName forest
splitForest name forst =
case maybeNode of
Nothing -> (Nothing,forest)
Just node -> (Just node, delete node forest)
where maybeNode = find ((name==).mainTable.rootLabel) forst
ws :: Parser Text
ws = cs <$> many (oneOf " \t")
@@ -82,22 +46,20 @@ pTreePath = do
let pp = map cs p
jpp = map cs <$> jp
return (init pp, (last pp, jpp))
where
pFieldForest :: Parser [Tree SelectItem]
pFieldForest = pFieldTree `sepBy1` lexeme (char ',')
pFieldTree :: Parser (Tree SelectItem)
pFieldTree = try (Node <$> pSelect <*> ( char '(' *> pFieldForest <* char ')'))
<|> Node <$> pSelect <*> pure []
pFieldTree = try (Node <$> pSelect <*> between (char '(') (char ')') pFieldForest)
<|> Node <$> pSelect <*> pure []
pStar :: Parser Text
pStar = cs <$> (string "*" *> pure ("*"::String))
pFieldName :: Parser Text
pFieldName = cs <$> (many1 (letter <|> digit <|> oneOf "_")
<?> "field name (* or [a..z0..9_])")
<?> "field name (* or [a..z0..9_])")
pJsonPathStep :: Parser Text
pJsonPathStep = cs <$> try (string "->" *> pFieldName)
@@ -116,22 +78,8 @@ pSelect = lexeme $
return ((s, Nothing), Nothing)
pOperator :: Parser Operator
pOperator = cs <$> ( try (string "lte") -- has to be before lt
<|> try (string "lt")
<|> try (string "eq")
<|> try (string "gte") -- has to be before gh
<|> try (string "gt")
<|> try (string "lt")
<|> try (string "neq")
<|> try (string "like")
<|> try (string "ilike")
<|> try (string "in")
<|> try (string "notin")
<|> try (string "is" )
<|> try (string "isnot")
<|> try (string "@@")
<?> "operator (eq, gt, ...)"
)
pOperator = cs <$> (pOp <?> "operator (eq, gt, ...)")
where pOp = foldl (<|>) empty $ map (try . string . cs . fst) operators
pValue :: Parser FValue
pValue = VText <$> (cs <$> many anyChar)