// Extracts the root type of the operation from the schema.
func getOperationRootType(schema types.GraphQLSchema, operation ast.Definition, r chan *types.GraphQLResult) (objType *types.GraphQLObjectType) {
if operation == nil {
var result types.GraphQLResult
err := graphqlerrors.NewGraphQLFormattedError("Can only execute queries and mutations")
result.Errors = append(result.Errors, err)
r <- &result
return objType
}
switch operation.GetOperation() {
case "query":
return schema.GetQueryType()
case "mutation":
mutationType := schema.GetMutationType()
if mutationType.Name == "" {
var result types.GraphQLResult
err := graphqlerrors.NewGraphQLFormattedError("Schema is not configured for mutations")
result.Errors = append(result.Errors, err)
r <- &result
return objType
}
return mutationType
default:
var result types.GraphQLResult
err := graphqlerrors.NewGraphQLFormattedError("Can only execute queries and mutations")
result.Errors = append(result.Errors, err)
r <- &result
return objType
}
}
/**
* This method looks up the field on the given type defintion.
* It has special casing for the two introspection fields, __schema
* and __typename. __typename is special because it can always be
* queried as a field, even in situations where no other fields
* are allowed, like on a Union. __schema could get automatically
* added to the query type, but that would require mutating type
* definitions, which would cause issues.
*/
func getFieldDef(schema types.GraphQLSchema, parentType *types.GraphQLObjectType, fieldName string) *types.GraphQLFieldDefinition {
if parentType == nil {
return nil
}
if fieldName == types.SchemaMetaFieldDef.Name &&
schema.GetQueryType() == parentType {
return types.SchemaMetaFieldDef
}
if fieldName == types.TypeMetaFieldDef.Name &&
schema.GetQueryType() == parentType {
return types.TypeMetaFieldDef
}
if fieldName == types.TypeNameMetaFieldDef.Name {
return types.TypeNameMetaFieldDef
}
return parentType.GetFields()[fieldName]
}