graphql-engine/server/src-lib/Hasura/RQL/DDL/ComputedField.hs
Antoine Leblanc cc6c86aeab Clean metadata arguments
## Description

Thanks to #1664, the Metadata API types no longer require a `ToJSON` instance. This PR follows up with a cleanup of the types of the arguments to the metadata API:
- whenever possible, it moves those argument types to where they're used (RQL.DDL.*)
- it removes all unrequired instances (mostly `ToJSON`)

This PR does not attempt to do it for _all_ such argument types. For some of the metadata operations, the type used to describe the argument to the API and used to represent the value in the metadata are one and the same (like for `CreateEndpoint`). Sometimes, the two types are intertwined in complex ways (`RemoteRelationship` and `RemoteRelationshipDef`). In the spirit of only doing uncontroversial cleaning work, this PR only moves types that are not used outside of RQL.DDL.

Furthermore, this is a small step towards separating the different types all jumbled together in RQL.Types.

## Notes

This PR also improves several `FromJSON` instances to make use of `withObject`, and to use a human readable string instead of a type name in error messages whenever possible. For instance:
- before: `expected Object for Object, but encountered X`
  after: `expected Object for add computed field, but encountered X`
- before: `Expecting an object for update query`
  after: `expected Object for update query, but encountered X`

This PR also renames `CreateFunctionPermission` to `FunctionPermissionArgument`, to remove the quite surprising `type DropFunctionPermission = CreateFunctionPermission`.

This PR also deletes some dead code, mostly in RQL.DML.

This PR also moves a PG-specific source resolving function from DDL.Schema.Source to the only place where it is used: App.hs.

https://github.com/hasura/graphql-engine-mono/pull/1844

GitOrigin-RevId: a594521194bb7fe6a111b02a9e099896f9fed59c
2021-07-27 10:42:51 +00:00

128 lines
4.1 KiB
Haskell

{- |
Description: Add/Drop computed fields in metadata
-}
module Hasura.RQL.DDL.ComputedField
( AddComputedField(..)
, ComputedFieldDefinition(..)
, runAddComputedField
, DropComputedField
, runDropComputedField
, dropComputedFieldInMetadata
) where
import Hasura.Prelude
import qualified Data.HashMap.Strict.InsOrd as OMap
import Data.Aeson
import Data.Text.Extended
import qualified Hasura.SQL.AnyBackend as AB
import Hasura.Base.Error
import Hasura.EncJSON
import Hasura.RQL.DDL.Deps
import Hasura.RQL.DDL.Permission
import Hasura.RQL.Types
data AddComputedField b
= AddComputedField
{ _afcSource :: !SourceName
, _afcTable :: !(TableName b)
, _afcName :: !ComputedFieldName
, _afcDefinition :: !(ComputedFieldDefinition b)
, _afcComment :: !(Maybe Text)
} deriving stock (Generic)
instance (Backend b) => ToJSON (AddComputedField b) where
toJSON = genericToJSON hasuraJSON
instance (Backend b) => FromJSON (AddComputedField b) where
parseJSON = withObject "add computed field" $ \o ->
AddComputedField
<$> o .:? "source" .!= defaultSource
<*> o .: "table"
<*> o .: "name"
<*> o .: "definition"
<*> o .:? "comment"
runAddComputedField
:: forall b m
. (BackendMetadata b, MonadError QErr m, CacheRWM m, MetadataM m)
=> AddComputedField b
-> m EncJSON
runAddComputedField q = do
withPathK "table" $ askTabInfo @b source table
let metadataObj = MOSourceObjId source
$ AB.mkAnyBackend
$ SMOTableObj @b table
$ MTOComputedField computedFieldName
metadata = ComputedFieldMetadata computedFieldName (_afcDefinition q) (_afcComment q)
buildSchemaCacheFor metadataObj
$ MetadataModifier
$ tableMetadataSetter source table.tmComputedFields
%~ OMap.insert computedFieldName metadata
pure successMsg
where
source = _afcSource q
table = _afcTable q
computedFieldName = _afcName q
data DropComputedField b
= DropComputedField
{ _dccSource :: !SourceName
, _dccTable :: !(TableName b)
, _dccName :: !ComputedFieldName
, _dccCascade :: !Bool
}
instance (Backend b) => FromJSON (DropComputedField b) where
parseJSON = withObject "drop computed field" $ \o ->
DropComputedField
<$> o .:? "source" .!= defaultSource
<*> o .: "table"
<*> o .: "name"
<*> o .:? "cascade" .!= False
runDropComputedField
:: forall b m
. (QErrM m, CacheRWM m, MetadataM m, BackendMetadata b)
=> DropComputedField b -> m EncJSON
runDropComputedField (DropComputedField source table computedField cascade) = do
-- Validation
fields <- withPathK "table" $ _tciFieldInfoMap <$> askTableCoreInfo @b source table
void $ withPathK "name" $ askComputedFieldInfo fields computedField
-- Dependencies check
sc <- askSchemaCache
let deps = getDependentObjs sc
$ SOSourceObj source
$ AB.mkAnyBackend
$ SOITableObj @b table
$ TOComputedField computedField
when (not cascade && not (null deps)) $ reportDeps deps
withNewInconsistentObjsCheck do
metadataModifiers <- mapM purgeComputedFieldDependency deps
buildSchemaCache $ MetadataModifier $
tableMetadataSetter @b source table
%~ dropComputedFieldInMetadata computedField . foldl' (.) id metadataModifiers
pure successMsg
where
purgeComputedFieldDependency = \case
-- TODO: do a better check of ensuring that the dependency is as expected.
-- i.e, the only allowed dependent objects on a computed fields are permissions
-- on the same table
SOSourceObj _ exists
| Just (SOITableObj _ (TOPerm roleName permType))
<- AB.unpackAnyBackend @b exists ->
pure $ dropPermissionInMetadata roleName permType
d -> throw500 $ "unexpected dependency for computed field "
<> computedField <<> "; " <> reportSchemaObj d
dropComputedFieldInMetadata
:: ComputedFieldName -> TableMetadata b -> TableMetadata b
dropComputedFieldInMetadata name =
tmComputedFields %~ OMap.delete name