forked from OSS/graphql
770df82718
Now there is one `Resolver` type and the `Output` and `Scalar` types have been removed. This should be closer to the final Schema definition API.
42 lines
1.3 KiB
Haskell
42 lines
1.3 KiB
Haskell
{-# LANGUAGE CPP #-}
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module Data.GraphQL.Execute (execute) where
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#if !MIN_VERSION_base(4,8,0)
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import Control.Applicative ((<$>))
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#endif
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import Control.Applicative (Alternative)
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import Data.Maybe (catMaybes)
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import qualified Data.Aeson as Aeson
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import Data.GraphQL.AST
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import Data.GraphQL.Schema (Schema(..))
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import qualified Data.GraphQL.Schema as Schema
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execute
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:: Alternative f
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=> Schema.Schema f -> Schema.Subs -> Document -> f Aeson.Value
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execute (Schema resolvs) subs = Schema.resolvers resolvs . rootFields subs
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rootFields :: Schema.Subs -> Document -> [Field]
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rootFields subs (Document [DefinitionOperation (Query (Node _varDefs _ _ sels))]) =
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Schema.fields $ substitute subs <$> sels
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rootFields _ _ = []
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substitute :: Schema.Subs -> Selection -> Selection
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substitute subs (SelectionField (Field alias name args directives sels)) =
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SelectionField $ Field
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alias
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name
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-- TODO: Get rid of `catMaybes`, invalid arguments should raise an error
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(catMaybes $ subsArg subs <$> args)
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directives
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(substitute subs <$> sels)
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substitute _ sel = sel
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-- TODO: Support different value types
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subsArg :: Schema.Subs -> Argument -> Maybe Argument
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subsArg subs (Argument n (ValueVariable (Variable v))) =
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Argument n . ValueString . StringValue <$> subs v
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subsArg _ arg = Just arg
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