Allow alias and hint for columns in query string

src/PostgREST/ApiRequest.hs

@@ -46,6 +46,7 @@ import Web.Cookie (parseCookies)
 
 import PostgREST.ApiRequest.QueryParams (QueryParams (..))
 import PostgREST.ApiRequest.Types (ApiRequestError (..),
+ ColumnItem (..),
  RangeError (..))
 import PostgREST.Config (AppConfig (..),
  OpenAPIMode (..))
@@ -55,8 +56,7 @@ import PostgREST.RangeQuery (NonnegRange, allRange,
  hasLimitZero,
  rangeRequested)
 import PostgREST.SchemaCache (SchemaCache (..))
-import PostgREST.SchemaCache.Identifiers (FieldName,
- QualifiedIdentifier (..),
+import PostgREST.SchemaCache.Identifiers (QualifiedIdentifier (..),
  Schema)
 
 import qualified PostgREST.ApiRequest.Preferences as Preferences
@@ -117,7 +117,7 @@ data ApiRequest = ApiRequest {
  , iPayload :: Maybe Payload -- ^ Data sent by client and used for mutation actions
  , iPreferences :: Preferences.Preferences -- ^ Prefer header values
  , iQueryParams :: QueryParams.QueryParams
- , iColumns :: S.Set (Tree FieldName)  -- ^ parsed colums from &columns parameter and payload
+ , iColumns :: S.Set (Tree ColumnItem) -- ^ parsed colums from &columns parameter and payload
  , iHeaders :: [(ByteString, ByteString)] -- ^ HTTP request headers
  , iCookies :: [(ByteString, ByteString)] -- ^ Request Cookies
  , iPath :: ByteString -- ^ Raw request path
@@ -237,12 +237,12 @@ getRanges method QueryParams{qsOrder,qsRanges} hdrs
  isInvalidRange = topLevelRange == emptyRange && not (hasLimitZero limitRange)
  topLevelRange = fromMaybe allRange $ HM.lookup "limit" ranges -- if no limit is specified, get all the request rows
 
-getPayload :: RequestBody -> MediaType -> QueryParams.QueryParams -> Action -> Either ApiRequestError (Maybe Payload, S.Set (Tree FieldName))
+getPayload :: RequestBody -> MediaType -> QueryParams.QueryParams -> Action -> Either ApiRequestError (Maybe Payload, S.Set (Tree ColumnItem))
 getPayload reqBody contentMediaType QueryParams{qsColumns} action = do
  checkedPayload <- if shouldParsePayload then payload else Right Nothing
  let cols = case (checkedPayload, columns) of
- (Just ProcessedJSON{payKeys}, _) -> S.map (`Node` []) payKeys
- (Just ProcessedUrlEncoded{payKeys}, _) -> S.map (`Node` []) payKeys
+ (Just ProcessedJSON{payKeys}, _) -> S.map ((`Node` []) . ColumnField) payKeys
+ (Just ProcessedUrlEncoded{payKeys}, _) -> S.map ((`Node` []) . ColumnField) payKeys
  (Just RawJSON{}, Just cls) -> S.fromList cls
  _ -> S.empty
  return (checkedPayload, cols)

src/PostgREST/ApiRequest/QueryParams.hs

@@ -44,10 +44,10 @@ import PostgREST.RangeQuery (NonnegRange, allRange,
 import PostgREST.SchemaCache.Identifiers (FieldName)
 
 import PostgREST.ApiRequest.Types (AggregateFunction (..),
- EmbedParam (..), EmbedPath, Field,
- Filter (..), FtsOperator (..),
- Hint, JoinType (..),
- JsonOperand (..),
+ ColumnItem (..), EmbedParam (..),
+ EmbedPath, Field, Filter (..),
+ FtsOperator (..), Hint,
+ JoinType (..), JsonOperand (..),
  JsonOperation (..), JsonPath,
  ListVal, LogicOperator (..),
  LogicTree (..), OpExpr (..),
@@ -73,7 +73,7 @@ data QueryParams =
  -- ^ &order parameters for each level
  , qsLogic :: [(EmbedPath, LogicTree)]
  -- ^ &and and &or parameters used for complex boolean logic
- , qsColumns :: Maybe [Tree FieldName]
+ , qsColumns :: Maybe [Tree ColumnItem]
  -- ^ &columns parameter and payload
  , qsSelect :: [Tree SelectItem]
  -- ^ &select parameter used to shape the response
@@ -261,8 +261,8 @@ pRequestLogicTree (k, v) = mapError $ (,) <$> embedPath <*> logicTree
  P.parse pLogicTree ("failed to parse logic tree (" ++ toS v ++ ")") $ toS (op <> v)
 
 
--- Satisfies the form: /products?columns=name,suppliers(name)
-pRequestColumns :: Maybe Text -> Either QPError (Maybe [Tree FieldName])
+-- Satisfies the form: /products?columns=name,sup:suppliers!fk(name)
+pRequestColumns :: Maybe Text -> Either QPError (Maybe [Tree ColumnItem])
 pRequestColumns colStr =
  case colStr of
  Just str ->
@@ -479,11 +479,13 @@ pRelationSelect = lexeme $ do
  try (void $ lookAhead (string "("))
  return $ SelectRelation name alias hint jType
 
-pRelationColumn :: Parser FieldName
+pRelationColumn :: Parser ColumnItem
 pRelationColumn = lexeme $ do
+ alias <- optionMaybe ( try(pFieldName <* aliasSeparator) )
  name <- pFieldName
+ (hint, _) <- pEmbedParams
  try (void $ lookAhead (string "("))
- return name
+ return $ ColumnRelation name alias hint
 
 -- |
 -- Parse regular fields in select
@@ -852,17 +854,17 @@ pLogicPath = do
 pColumns :: Parser [FieldName]
 pColumns = pFieldName `sepBy1` lexeme (char ',')
 
-pColumnForest :: Parser [Tree FieldName]
+pColumnForest :: Parser [Tree ColumnItem]
 pColumnForest = pColumnTree `sepBy1` lexeme (char ',')
  where
  pColumnTree = Node <$> try pRelationColumn <*> between (char '(') (char ')') pColumnForest <|>
  Node <$> pColumnName <*> pure []
 
-pColumnName :: Parser FieldName
+pColumnName :: Parser ColumnItem
 pColumnName = lexeme $ do
  fld <- pFieldName
  pEnd
- return fld
+ return $ ColumnField fld
  where
  pEnd = try (void $ lookAhead (string ")")) <|>
  try (void $ lookAhead (string ",")) <|>

src/PostgREST/ApiRequest/Types.hs

@@ -33,6 +33,7 @@ module PostgREST.ApiRequest.Types
  , QuantOperator(..)
  , FtsOperator(..)
  , SelectItem(..)
+ , ColumnItem(..)
  ) where
 
 import PostgREST.MediaType (MediaType (..))
@@ -68,6 +69,15 @@ data SelectItem
  }
  deriving (Eq, Show)
 
+data ColumnItem
+ = ColumnField FieldName
+ | ColumnRelation
+ { colRelation :: FieldName
+ , colAlias :: Maybe Alias
+ , colHint :: Maybe Hint
+ }
+ deriving (Eq, Show, Ord)
+
 data ApiRequestError
  = AggregatesNotAllowed
  | AmbiguousRelBetween Text Text [Relationship]

src/PostgREST/Plan.hs

@@ -170,7 +170,7 @@ callReadPlan :: QualifiedIdentifier -> AppConfig -> SchemaCache -> ApiRequest ->
 callReadPlan identifier conf sCache apiRequest@ApiRequest{iPreferences=Preferences{..},..} invMethod = do
  let paramKeys = case invMethod of
  InvRead _ -> S.fromList $ fst <$> qsParams'
- Inv -> S.map rootLabel iColumns
+ Inv -> S.map (getColumnAsText . rootLabel) iColumns
  proc@Function{..} <- mapLeft ApiRequestError $
  findProc identifier paramKeys (preferParameters == Just SingleObject) (dbRoutines sCache) iContentMediaType (invMethod == Inv)
  let relIdentifier = QualifiedIdentifier pdSchema (fromMaybe pdName $ Routine.funcTableName proc) -- done so a set returning function can embed other relations
@@ -942,7 +942,7 @@ mutatePlan mutation qi ApiRequest{iPreferences=Preferences{..}, ..} SchemaCache{
  combinedLogic = foldr (addFilterToLogicForest . resolveFilter ctx) logic qsFiltersRoot
  body = payRaw <$> iPayload -- the body is assumed to be json at this stage(ApiRequest validates)
  applyDefaults = preferMissing == Just ApplyDefaults
- typedColumnsOrError = resolveOrError ctx tbl `traverse` S.toList (S.map rootLabel iColumns)
+ typedColumnsOrError = resolveOrError ctx tbl `traverse` S.toList (S.map (getColumnAsText . rootLabel) iColumns)
 
 resolveOrError :: ResolverContext -> Maybe Table -> FieldName -> Either ApiRequestError CoercibleField
 resolveOrError _ Nothing _ = Left NotFound
@@ -1051,3 +1051,9 @@ negotiateContent conf ApiRequest{iAction=act, iPreferences=Preferences{preferRep
  when' :: Bool -> Maybe a -> Maybe a
  when' True (Just a) = Just a
  when' _ _ = Nothing
+
+getColumnAsText :: ColumnItem -> Text
+getColumnAsText colItem =
+ case colItem of
+ ColumnField col -> col
+ ColumnRelation{colRelation} -> colRelation