graphql-engine/server/src-lib/Hasura/GraphQL/Schema/Update.hs
Samir Talwar c980af1b8f Move MkTypename and NamingCase into their own modules.
This moves `MkTypename` and `NamingCase` into their own modules, with the intent of reducing the scope of the schema parsers code, and trying to reduce imports of large modules when small ones will do.

PR-URL: https://github.com/hasura/graphql-engine-mono/pull/4978
GitOrigin-RevId: 19541257fe010035390f6183a4eaa37bae0d3ca1
2022-07-12 14:01:28 +00:00

356 lines
13 KiB
Haskell

{-# LANGUAGE ApplicativeDo #-}
{-# LANGUAGE TemplateHaskell #-}
-- | This module provides common building blocks for composing Schema Parsers
-- used in the schema of Update Mutations.
module Hasura.GraphQL.Schema.Update
( UpdateOperator (..),
updateOperator,
buildUpdateOperators,
presetColumns,
setOp,
incOp,
updateTable,
updateTableByPk,
)
where
import Data.Has (Has)
import Data.HashMap.Strict qualified as M
import Data.HashMap.Strict.Extended qualified as M
import Data.List.NonEmpty qualified as NE
import Data.Text.Extended (commaSeparated, dquote, (<>>))
import Hasura.Base.Error (QErr)
import Hasura.GraphQL.Schema.Backend (BackendSchema (..), BackendTableSelectSchema (..), MonadBuildSchema, columnParser)
import Hasura.GraphQL.Schema.BoolExp (boolExp)
import Hasura.GraphQL.Schema.Common (Scenario (..), mapField, partialSQLExpToUnpreparedValue)
import Hasura.GraphQL.Schema.Mutation (mutationSelectionSet, primaryKeysArguments)
import Hasura.GraphQL.Schema.NamingCase
import Hasura.GraphQL.Schema.Parser qualified as P
import Hasura.GraphQL.Schema.Table (getTableGQLName, tableColumns, tablePermissions, tableUpdateColumns)
import Hasura.GraphQL.Schema.Typename
import Hasura.Prelude
import Hasura.RQL.IR.BoolExp (AnnBoolExp, annBoolExpTrue)
import Hasura.RQL.IR.Returning (MutationOutputG (..))
import Hasura.RQL.IR.Root (RemoteRelationshipField)
import Hasura.RQL.IR.Update (AnnotatedUpdateG (..))
import Hasura.RQL.IR.Value
import Hasura.RQL.Types.Backend (Backend (..))
import Hasura.RQL.Types.Column (ColumnInfo (..), isNumCol)
import Hasura.RQL.Types.Source
import Hasura.RQL.Types.Table
import Language.GraphQL.Draft.Syntax (Description (..), Name (..), Nullability (..), litName)
-- | @UpdateOperator b m n op@ represents one single update operator for a
-- backend @b@.
--
-- The type variable @op@ is the backend-specific data type that represents
-- update operators, typically in the form of a sum-type with an
-- @UnpreparedValue b@ in each constructor.
--
-- The @UpdateOperator b m n@ is a @Functor@. There exist building blocks of
-- common update operators (such as 'setOp', etc.) which have @op ~
-- UnpreparedValue b@. The Functor instance lets you wrap the generic update
-- operators in backend-specific tags.
data UpdateOperator b m n op = UpdateOperator
{ updateOperatorApplicableColumn :: ColumnInfo b -> Bool,
updateOperatorParser ::
Name ->
TableName b ->
NonEmpty (ColumnInfo b) ->
m (P.InputFieldsParser n (HashMap (Column b) op))
}
deriving (Functor)
-- | The top-level component for building update operators parsers.
--
-- * It implements the @preset@ functionality from Update Permissions (see
-- <https://hasura.io/docs/latest/graphql/core/auth/authorization/permission-rules.html#column-presets
-- Permissions user docs>). Use the 'presetColumns' function to extract those from the update permissions.
-- * It validates that that the update fields parsed are sound when taken as a
-- whole, i.e. that some changes are actually specified (either in the
-- mutation query text or in update preset columns) and that each column is
-- only used in one operator.
buildUpdateOperators ::
forall b r m n op.
MonadBuildSchema b r m n =>
-- | Columns with @preset@ expressions
(HashMap (Column b) op) ->
-- | Update operators to include in the Schema
[UpdateOperator b m n op] ->
TableInfo b ->
m (P.InputFieldsParser n (HashMap (Column b) op))
buildUpdateOperators presetCols ops tableInfo = do
parsers :: P.InputFieldsParser n [HashMap (Column b) op] <-
sequenceA . catMaybes <$> traverse (runUpdateOperator tableInfo) ops
pure $
parsers
`P.bindFields` ( \opExps -> do
let withPreset = presetCols : opExps
mergeDisjoint @b withPreset
)
-- | The columns that have 'preset' definitions applied to them. (see
-- <https://hasura.io/docs/latest/graphql/core/auth/authorization/permission-rules.html#column-presets
-- Permissions user docs>)
presetColumns :: UpdPermInfo b -> HashMap (Column b) (UnpreparedValue b)
presetColumns = fmap partialSQLExpToUnpreparedValue . upiSet
-- | Produce an InputFieldsParser from an UpdateOperator, but only if the operator
-- applies to the table (i.e., it admits a non-empty column set).
runUpdateOperator ::
forall b r m n op.
MonadBuildSchema b r m n =>
TableInfo b ->
UpdateOperator b m n op ->
m
( Maybe
( P.InputFieldsParser
n
(HashMap (Column b) op)
)
)
runUpdateOperator tableInfo UpdateOperator {..} = do
let tableName = tableInfoName tableInfo
tableGQLName <- getTableGQLName tableInfo
columns <- tableUpdateColumns tableInfo
let applicableCols :: Maybe (NonEmpty (ColumnInfo b)) =
nonEmpty . filter updateOperatorApplicableColumn $ columns
(sequenceA :: Maybe (m a) -> m (Maybe a))
(applicableCols <&> updateOperatorParser tableGQLName tableName)
-- | Ensure that /some/ updates have been specified in a mutation.
ensureNonEmpty ::
forall b m t.
(P.MonadParse m, Backend b) =>
[Text] ->
[HashMap (Column b) t] ->
m ()
ensureNonEmpty allowedOperators parsedResults =
when (null $ M.unions parsedResults) $
P.parseError $
"At least any one of "
<> commaSeparated allowedOperators
<> " is expected"
-- | Merge the results of parsed update operators. Throws an error if the same
-- column has been specified in multiple operators.
mergeDisjoint ::
forall b m t.
(Backend b, P.MonadParse m) =>
[HashMap (Column b) t] ->
m (HashMap (Column b) t)
mergeDisjoint parsedResults = do
let unioned = M.unionsAll parsedResults
duplicates = M.keys $ M.filter (not . null . NE.tail) unioned
unless (null duplicates) $
P.parseError
( "Column found in multiple operators: "
<> commaSeparated (map dquote duplicates)
<> "."
)
return $ M.map NE.head unioned
-- | Construct a parser for a single update operator.
--
-- @updateOperator _ "op" fp MkOp ["col1","col2"]@ gives a parser that accepts
-- objects in the shape of:
--
-- > op: {
-- > col1: "x",
-- > col2: "y"
-- > }
--
-- And (morally) parses into values:
--
-- > M.fromList [("col1", MkOp (fp "x")), ("col2", MkOp (fp "y"))]
updateOperator ::
forall n r m b a.
(P.MonadParse n, MonadReader r m, Has MkTypename r, Backend b) =>
Name ->
Name ->
(ColumnInfo b -> m (P.Parser 'P.Both n a)) ->
NonEmpty (ColumnInfo b) ->
Description ->
Description ->
m (P.InputFieldsParser n (HashMap (Column b) a))
updateOperator tableGQLName opName mkParser columns opDesc objDesc = do
fieldParsers :: NonEmpty (P.InputFieldsParser n (Maybe (Column b, a))) <-
for columns \columnInfo -> do
let fieldName = ciName columnInfo
fieldDesc = ciDescription columnInfo
fieldParser <- mkParser columnInfo
pure $
P.fieldOptional fieldName fieldDesc fieldParser
`mapField` \value -> (ciColumn columnInfo, value)
objName <- mkTypename $ tableGQLName <> opName <> $$(litName "_input")
pure $
fmap (M.fromList . (fold :: Maybe [(Column b, a)] -> [(Column b, a)])) $
P.fieldOptional opName (Just opDesc) $
P.object objName (Just objDesc) $
(catMaybes . toList) <$> sequenceA fieldParsers
{-# ANN updateOperator ("HLint: ignore Use tuple-section" :: String) #-}
setOp ::
forall b n r m.
( BackendSchema b,
MonadReader r m,
Has MkTypename r,
Has NamingCase r,
MonadError QErr m,
P.MonadSchema n m
) =>
UpdateOperator b m n (UnpreparedValue b)
setOp = UpdateOperator {..}
where
updateOperatorApplicableColumn = const True
updateOperatorParser tableGQLName tableName columns = do
let typedParser columnInfo =
fmap mkParameter
<$> columnParser
(ciType columnInfo)
(Nullability $ ciIsNullable columnInfo)
updateOperator
tableGQLName
$$(litName "_set")
typedParser
columns
"sets the columns of the filtered rows to the given values"
(Description $ "input type for updating data in table " <>> tableName)
incOp ::
forall b m n r.
( Backend b,
MonadReader r m,
MonadError QErr m,
P.MonadSchema n m,
BackendSchema b,
Has MkTypename r,
Has NamingCase r
) =>
UpdateOperator b m n (UnpreparedValue b)
incOp = UpdateOperator {..}
where
updateOperatorApplicableColumn = isNumCol
updateOperatorParser tableGQLName tableName columns = do
let typedParser columnInfo =
fmap mkParameter
<$> columnParser
(ciType columnInfo)
(Nullability $ ciIsNullable columnInfo)
updateOperator
tableGQLName
$$(litName "_inc")
typedParser
columns
"increments the numeric columns with given value of the filtered values"
(Description $ "input type for incrementing numeric columns in table " <>> tableName)
-- | Construct a root field, normally called update_tablename, that can be used
-- to update rows in a DB table specified by filters. Only returns a parser if
-- there are columns the user is allowed to update; otherwise returns Nothing.
updateTable ::
forall b r m n.
( MonadBuildSchema b r m n,
BackendTableSelectSchema b
) =>
-- | backend-specific data needed to perform an update mutation
P.InputFieldsParser n (BackendUpdate b (UnpreparedValue b)) ->
Scenario ->
-- | table source
SourceInfo b ->
-- | table info
TableInfo b ->
-- | field display name
Name ->
-- | field description, if any
Maybe Description ->
m (Maybe (P.FieldParser n (AnnotatedUpdateG b (RemoteRelationshipField UnpreparedValue) (UnpreparedValue b))))
updateTable backendUpdate scenario sourceInfo tableInfo fieldName description = runMaybeT do
let tableName = tableInfoName tableInfo
columns = tableColumns tableInfo
whereName = $$(litName "where")
whereDesc = "filter the rows which have to be updated"
viewInfo = _tciViewInfo $ _tiCoreInfo tableInfo
guard $ isMutable viIsUpdatable viewInfo
updatePerms <- MaybeT $ _permUpd <$> tablePermissions tableInfo
-- If we're in a frontend scenario, we should not include backend_only updates
-- For more info see Note [Backend only permissions]
guard $ not $ scenario == Frontend && upiBackendOnly updatePerms
whereArg <- lift $ P.field whereName (Just whereDesc) <$> boolExp sourceInfo tableInfo
selection <- lift $ mutationSelectionSet sourceInfo tableInfo
let argsParser = liftA2 (,) backendUpdate whereArg
pure $
P.subselection fieldName description argsParser selection
<&> mkUpdateObject tableName columns updatePerms . fmap MOutMultirowFields
-- | Construct a root field, normally called 'update_tablename_by_pk', that can be used
-- to update a single in a DB table, specified by primary key. Only returns a
-- parser if there are columns the user is allowed to update and if the user has
-- select permissions on all primary keys; otherwise returns Nothing.
updateTableByPk ::
forall b r m n.
MonadBuildSchema b r m n =>
BackendTableSelectSchema b =>
-- | backend-specific data needed to perform an update mutation
P.InputFieldsParser n (BackendUpdate b (UnpreparedValue b)) ->
Scenario ->
-- | table source
SourceInfo b ->
-- | table info
TableInfo b ->
-- | field display name
Name ->
-- | field description, if any
Maybe Description ->
m (Maybe (P.FieldParser n (AnnotatedUpdateG b (RemoteRelationshipField UnpreparedValue) (UnpreparedValue b))))
updateTableByPk backendUpdate scenario sourceInfo tableInfo fieldName description = runMaybeT $ do
let columns = tableColumns tableInfo
tableName = tableInfoName tableInfo
viewInfo = _tciViewInfo $ _tiCoreInfo tableInfo
guard $ isMutable viIsUpdatable viewInfo
updatePerms <- MaybeT $ _permUpd <$> tablePermissions tableInfo
-- If we're in a frontend scenario, we should not include backend_only updates
-- For more info see Note [Backend only permissions]
guard $ not $ scenario == Frontend && upiBackendOnly updatePerms
pkArgs <- MaybeT $ primaryKeysArguments tableInfo
selection <- MaybeT $ tableSelectionSet sourceInfo tableInfo
lift $ do
tableGQLName <- getTableGQLName tableInfo
pkObjectName <- mkTypename $ tableGQLName <> $$(litName "_pk_columns_input")
let pkFieldName = $$(litName "pk_columns")
pkObjectDesc = Description $ "primary key columns input for table: " <> unName tableGQLName
pkParser = P.object pkObjectName (Just pkObjectDesc) pkArgs
argsParser = (,) <$> backendUpdate <*> P.field pkFieldName Nothing pkParser
pure $
P.subselection fieldName description argsParser selection
<&> mkUpdateObject tableName columns updatePerms . fmap MOutSinglerowObject
mkUpdateObject ::
Backend b =>
TableName b ->
[ColumnInfo b] ->
UpdPermInfo b ->
( ( BackendUpdate b (UnpreparedValue b),
AnnBoolExp b (UnpreparedValue b)
),
MutationOutputG b (RemoteRelationshipField UnpreparedValue) (UnpreparedValue b)
) ->
AnnotatedUpdateG b (RemoteRelationshipField UnpreparedValue) (UnpreparedValue b)
mkUpdateObject _auTable _auAllCols updatePerms ((_auBackend, whereExp), _auOutput) =
AnnotatedUpdateG {..}
where
permissionFilter = fmap partialSQLExpToUnpreparedValue <$> upiFilter updatePerms
_auWhere = (permissionFilter, whereExp)
_auCheck = maybe annBoolExpTrue ((fmap . fmap) partialSQLExpToUnpreparedValue) $ upiCheck updatePerms