diff options
Diffstat (limited to 'Data/GraphQL/Execute.hs')
| -rw-r--r-- | Data/GraphQL/Execute.hs | 69 |
1 files changed, 41 insertions, 28 deletions
diff --git a/Data/GraphQL/Execute.hs b/Data/GraphQL/Execute.hs index a7e3c91..7609561 100644 --- a/Data/GraphQL/Execute.hs +++ b/Data/GraphQL/Execute.hs @@ -1,58 +1,71 @@ +{-# LANGUAGE OverloadedStrings #-} -- | This module provides the function to execute a @GraphQL@ request -- -- according to a 'Schema'. module Data.GraphQL.Execute (execute) where -import Control.Applicative (Alternative) -import Data.Maybe (catMaybes) +import Control.Applicative (Alternative, empty) +import qualified Data.List.NonEmpty as NE +import Data.List.NonEmpty (NonEmpty((:|))) import qualified Data.Aeson as Aeson +import qualified Data.HashMap.Strict as HashMap -import Data.GraphQL.AST -import Data.GraphQL.Schema (Schema(..)) +import qualified Data.GraphQL.AST as AST +import qualified Data.GraphQL.AST.Core as AST.Core +import qualified Data.GraphQL.AST.Transform as Transform +import Data.GraphQL.Schema (Schema) import qualified Data.GraphQL.Schema as Schema -import Data.GraphQL.Error - -- | Takes a 'Schema', a variable substitution function ('Schema.Subs'), and a -- @GraphQL@ 'document'. The substitution is applied to the document using -- 'rootFields', and the 'Schema''s resolvers are applied to the resulting fields. -- -- Returns the result of the query against the 'Schema' wrapped in a /data/ field, or -- errors wrapped in an /errors/ field. -execute :: Alternative f - => Schema.Schema f -> Schema.Subs -> Document -> f Aeson.Value -execute (Schema resolvs) subs doc = runCollectErrs res - where res = Schema.resolvers resolvs $ rootFields subs doc +execute + :: (Alternative f, Monad f) + => Schema f -> Schema.Subs -> AST.Document -> f Aeson.Value +execute schema subs doc = document schema =<< maybe empty pure (Transform.document subs doc) + +document :: Alternative f => Schema f -> AST.Core.Document -> f Aeson.Value +document schema (op :| []) = operation schema op +document _ _ = error "Multiple operations not supported yet" + +operation :: Alternative f => Schema f -> AST.Core.Operation -> f Aeson.Value +operation schema (AST.Core.Query flds) = + Aeson.Object . HashMap.singleton "data" + <$> Schema.resolve (NE.toList schema) (NE.toList flds) +operation _ _ = error "Mutations not supported yet" -- | Takes a variable substitution function and a @GraphQL@ document. -- If the document contains one query (and no other definitions) -- it applies the substitution to the query's set of selections -- and then returns their fields. -rootFields :: Schema.Subs -> Document -> [Field] -rootFields subs (Document [DefinitionOperation (Query (Node _varDefs _ _ sels))]) = - Schema.fields $ substitute subs <$> sels -rootFields _ _ = [] +-- rootFields :: Schema.Subs -> Document -> [Field] +-- rootFields subs (Document [DefinitionOperation (Query (Node _varDefs _ _ sels))]) = +-- Schema.fields $ substitute subs <$> sels +-- rootFields _ _ = [] -- | Takes a variable substitution function and a selection. If the -- selection is a field it applies the substitution to the field's -- arguments using 'subsArg', and recursively applies the substitution to -- the arguments of fields nested in the primary field. -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 +-- 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 -- | Takes a variable substitution function and an argument. If the -- argument's value is a variable the substitution is applied to the -- variable's name. -subsArg :: Schema.Subs -> Argument -> Maybe Argument -subsArg subs (Argument n (ValueVariable (Variable v))) = - Argument n . ValueString <$> subs v -subsArg _ arg = Just arg +-- subsArg :: Schema.Subs -> Argument -> Maybe Argument +-- subsArg subs (Argument n (ValueVariable (Variable v))) = +-- Argument n . ValueString <$> subs v +-- subsArg _ arg = Just arg |
