forked from OSS/graphql
42 lines
1.3 KiB
Haskell
42 lines
1.3 KiB
Haskell
{-# LANGUAGE CPP #-}
|
|
module Data.GraphQL.Execute (execute) where
|
|
|
|
#if !MIN_VERSION_base(4,8,0)
|
|
import Control.Applicative ((<$>))
|
|
#endif
|
|
import Control.Applicative (Alternative)
|
|
import Data.Maybe (catMaybes)
|
|
|
|
import qualified Data.Aeson as Aeson
|
|
|
|
import Data.GraphQL.AST
|
|
import Data.GraphQL.Schema (Schema(..))
|
|
import qualified Data.GraphQL.Schema as Schema
|
|
|
|
execute
|
|
:: Alternative f
|
|
=> Schema.Schema f -> Schema.Subs -> Document -> f Aeson.Value
|
|
execute (Schema resolvs) subs = Schema.resolvers resolvs . rootFields subs
|
|
|
|
rootFields :: Schema.Subs -> Document -> [Field]
|
|
rootFields subs (Document [DefinitionOperation (Query (Node _varDefs _ _ sels))]) =
|
|
Schema.fields $ substitute subs <$> sels
|
|
rootFields _ _ = []
|
|
|
|
substitute :: Schema.Subs -> Selection -> Selection
|
|
substitute subs (SelectionField (Field alias name args directives sels)) =
|
|
SelectionField $ Field
|
|
alias
|
|
name
|
|
-- TODO: Get rid of `catMaybes`, invalid arguments should raise an error
|
|
(catMaybes $ subsArg subs <$> args)
|
|
directives
|
|
(substitute subs <$> sels)
|
|
substitute _ sel = sel
|
|
|
|
-- TODO: Support different value types
|
|
subsArg :: Schema.Subs -> Argument -> Maybe Argument
|
|
subsArg subs (Argument n (ValueVariable (Variable v))) =
|
|
Argument n . ValueString <$> subs v
|
|
subsArg _ arg = Just arg
|