// Extracts the root type of the operation from the schema.
func getOperationRootType(schema Schema, operation ast.Definition, r chan *Result) (objType *Object) {
if operation == nil {
var result Result
err := gqlerrors.NewFormattedError("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 Result
err := gqlerrors.NewFormattedError("Schema is not configured for mutations")
result.Errors = append(result.Errors, err)
r <- &result
return objType
}
return mutationType
default:
var result Result
err := gqlerrors.NewFormattedError("Can only execute queries and mutations")
result.Errors = append(result.Errors, err)
r <- &result
return objType
}
}
func completeValueCatchingError(eCtx *ExecutionContext, returnType Type, fieldASTs []*ast.Field, info ResolveInfo, result interface{}) (completed interface{}) {
// catch panic
defer func() interface{} {
if r := recover(); r != nil {
//send panic upstream
if _, ok := returnType.(*NonNull); ok {
panic(r)
}
if err, ok := r.(gqlerrors.FormattedError); ok {
eCtx.Errors = append(eCtx.Errors, err)
}
return completed
}
return completed
}()
if returnType, ok := returnType.(*NonNull); ok {
completed := completeValue(eCtx, returnType, fieldASTs, info, result)
return completed
}
completed = completeValue(eCtx, returnType, fieldASTs, info, result)
resultVal := reflect.ValueOf(completed)
if resultVal.IsValid() && resultVal.Type().Kind() == reflect.Func {
if propertyFn, ok := completed.(func() interface{}); ok {
return propertyFn()
}
err := gqlerrors.NewFormattedError("Error resolving func. Expected `func() interface{}` signature")
panic(gqlerrors.FormatError(err))
}
return completed
}
func invariant(condition bool, message string) error {
if !condition {
return gqlerrors.NewFormattedError(message)
}
return nil
}
func buildExecutionContext(p BuildExecutionCtxParams) *ExecutionContext {
eCtx := &ExecutionContext{}
operations := map[string]ast.Definition{}
fragments := map[string]ast.Definition{}
for _, statement := range p.AST.Definitions {
switch stm := statement.(type) {
case *ast.OperationDefinition:
key := ""
if stm.GetName() != nil && stm.GetName().Value != "" {
key = stm.GetName().Value
}
operations[key] = stm
case *ast.FragmentDefinition:
key := ""
if stm.GetName() != nil && stm.GetName().Value != "" {
key = stm.GetName().Value
}
fragments[key] = stm
default:
err := gqlerrors.NewFormattedError(
fmt.Sprintf("GraphQL cannot execute a request containing a %v", statement.GetKind()),
)
p.Result.Errors = append(p.Result.Errors, err)
p.ResultChan <- p.Result
return eCtx
}
}
if (p.OperationName == "") && (len(operations) != 1) {
err := gqlerrors.NewFormattedError("Must provide operation name if query contains multiple operations.")
p.Result.Errors = append(p.Result.Errors, err)
p.ResultChan <- p.Result
return eCtx
}
opName := p.OperationName
if opName == "" {
// get first opName
for k, _ := range operations {
opName = k
break
}
}
operation, found := operations[opName]
if !found {
err := gqlerrors.NewFormattedError(fmt.Sprintf(`Unknown operation named "%v".`, opName))
p.Result.Errors = append(p.Result.Errors, err)
p.ResultChan <- p.Result
return eCtx
}
variableValues, err := getVariableValues(p.Schema, operation.GetVariableDefinitions(), p.Args)
if err != nil {
p.Result.Errors = append(p.Result.Errors, gqlerrors.FormatError(err))
p.ResultChan <- p.Result
return eCtx
}
eCtx.Schema = p.Schema
eCtx.Fragments = fragments
eCtx.Root = p.Root
eCtx.Operation = operation
eCtx.VariableValues = variableValues
eCtx.Errors = p.Errors
return eCtx
}
func completeValue(eCtx *ExecutionContext, returnType Type, fieldASTs []*ast.Field, info ResolveInfo, result interface{}) interface{} {
// TODO: explore resolving go-routines in completeValue
resultVal := reflect.ValueOf(result)
if resultVal.IsValid() && resultVal.Type().Kind() == reflect.Func {
if propertyFn, ok := result.(func() interface{}); ok {
return propertyFn()
}
err := gqlerrors.NewFormattedError("Error resolving func. Expected `func() interface{}` signature")
panic(gqlerrors.FormatError(err))
}
if returnType, ok := returnType.(*NonNull); ok {
completed := completeValue(eCtx, returnType.OfType, fieldASTs, info, result)
if completed == nil {
err := NewLocatedError(
fmt.Sprintf("Cannot return null for non-nullable field %v.%v.", info.ParentType, info.FieldName),
FieldASTsToNodeASTs(fieldASTs),
)
panic(gqlerrors.FormatError(err))
}
return completed
}
if isNullish(result) {
return nil
}
// If field type is List, complete each item in the list with the inner type
if returnType, ok := returnType.(*List); ok {
resultVal := reflect.ValueOf(result)
err := invariant(
resultVal.IsValid() && resultVal.Type().Kind() == reflect.Slice,
"User Error: expected iterable, but did not find one.",
)
if err != nil {
panic(gqlerrors.FormatError(err))
}
itemType := returnType.OfType
completedResults := []interface{}{}
for i := 0; i < resultVal.Len(); i++ {
val := resultVal.Index(i).Interface()
completedItem := completeValueCatchingError(eCtx, itemType, fieldASTs, info, val)
completedResults = append(completedResults, completedItem)
}
return completedResults
}
// If field type is Scalar or Enum, serialize to a valid value, returning
// null if serialization is not possible.
if returnType, ok := returnType.(*Scalar); ok {
err := invariant(returnType.Serialize != nil, "Missing serialize method on type")
if err != nil {
panic(gqlerrors.FormatError(err))
}
serializedResult := returnType.Serialize(result)
if isNullish(serializedResult) {
return nil
}
return serializedResult
}
if returnType, ok := returnType.(*Enum); ok {
err := invariant(returnType.Serialize != nil, "Missing serialize method on type")
if err != nil {
panic(gqlerrors.FormatError(err))
}
serializedResult := returnType.Serialize(result)
if isNullish(serializedResult) {
return nil
}
return serializedResult
}
// ast.Field type must be Object, Interface or Union and expect sub-selections.
var objectType *Object
switch returnType := returnType.(type) {
case *Object:
objectType = returnType
case Abstract:
objectType = returnType.GetObjectType(result, info)
if objectType != nil && !returnType.IsPossibleType(objectType) {
panic(gqlerrors.NewFormattedError(
fmt.Sprintf(`Runtime Object type "%v" is not a possible type `+
`for "%v".`, objectType, returnType),
))
}
}
if objectType == nil {
return nil
}
// If there is an isTypeOf predicate function, call it with the
// current result. If isTypeOf returns false, then raise an error rather
// than continuing execution.
if objectType.IsTypeOf != nil && !objectType.IsTypeOf(result, info) {
panic(gqlerrors.NewFormattedError(
fmt.Sprintf(`Expected value of type "%v" but got: %T.`, objectType, result),
))
}
// Collect sub-fields to execute to complete this value.
subFieldASTs := map[string][]*ast.Field{}
visitedFragmentNames := map[string]bool{}
for _, fieldAST := range fieldASTs {
if fieldAST == nil {
continue
}
selectionSet := fieldAST.SelectionSet
if selectionSet != nil {
innerParams := CollectFieldsParams{
ExeContext: eCtx,
OperationType: objectType,
SelectionSet: selectionSet,
Fields: subFieldASTs,
VisitedFragmentNames: visitedFragmentNames,
}
subFieldASTs = collectFields(innerParams)
}
}
executeFieldsParams := ExecuteFieldsParams{
ExecutionContext: eCtx,
ParentType: objectType,
Source: result,
Fields: subFieldASTs,
}
results := executeFields(executeFieldsParams)
return results.Data
}