// jsonProperties returns parsed proto.Properties for the field and corrects JSONName attribute.
func jsonProperties(f reflect.StructField, origName bool) *proto.Properties {
var prop proto.Properties
prop.Init(f.Type, f.Name, f.Tag.Get("protobuf"), &f)
if origName || prop.JSONName == "" {
prop.JSONName = prop.OrigName
}
return &prop
}
// marshalObject writes a struct to the Writer.
func (m *Marshaler) marshalObject(out *errWriter, v proto.Message, indent, typeURL string) error {
// Prefer specialized marshalers if available
if mlr, ok := v.(json.Marshaler); ok {
bs, err := mlr.MarshalJSON()
if err != nil {
return err
}
if out.err != nil {
return out.err
}
_, out.err = out.writer.Write(bs)
return out.err
}
s := reflect.ValueOf(v).Elem()
// Handle well-known types.
if wkt, ok := v.(isWkt); ok {
switch wkt.XXX_WellKnownType() {
case "DoubleValue", "FloatValue", "Int64Value", "UInt64Value",
"Int32Value", "UInt32Value", "BoolValue", "StringValue", "BytesValue":
// "Wrappers use the same representation in JSON
// as the wrapped primitive type, ..."
sprop := proto.GetProperties(s.Type())
return m.marshalValue(out, sprop.Prop[0], s.Field(0), indent)
case "Any":
// Any is a bit more involved.
return m.marshalAny(out, v, indent)
case "Duration":
// "Generated output always contains 3, 6, or 9 fractional digits,
// depending on required precision."
s, ns := s.Field(0).Int(), s.Field(1).Int()
d := time.Duration(s)*time.Second + time.Duration(ns)*time.Nanosecond
x := fmt.Sprintf("%.9f", d.Seconds())
x = strings.TrimSuffix(x, "000")
x = strings.TrimSuffix(x, "000")
out.write(`"`)
out.write(x)
out.write(`s"`)
return out.err
case "Struct":
// Let marshalValue handle the `fields` map.
// TODO: pass the correct Properties if needed.
return m.marshalValue(out, &proto.Properties{}, s.Field(0), indent)
case "Timestamp":
// "RFC 3339, where generated output will always be Z-normalized
// and uses 3, 6 or 9 fractional digits."
s, ns := s.Field(0).Int(), s.Field(1).Int()
t := time.Unix(s, ns).UTC()
// time.RFC3339Nano isn't exactly right (we need to get 3/6/9 fractional digits).
x := t.Format("2006-01-02T15:04:05.000000000")
x = strings.TrimSuffix(x, "000")
x = strings.TrimSuffix(x, "000")
out.write(`"`)
out.write(x)
out.write(`Z"`)
return out.err
case "Value":
// Value has a single oneof.
kind := s.Field(0)
if kind.IsNil() {
// "absence of any variant indicates an error"
return errors.New("nil Value")
}
// oneof -> *T -> T -> T.F
x := kind.Elem().Elem().Field(0)
// TODO: pass the correct Properties if needed.
return m.marshalValue(out, &proto.Properties{}, x, indent)
}
}
out.write("{")
if m.Indent != "" {
out.write("\n")
}
firstField := true
if typeURL != "" {
if err := m.marshalTypeURL(out, indent, typeURL); err != nil {
return err
}
firstField = false
}
for i := 0; i < s.NumField(); i++ {
value := s.Field(i)
valueField := s.Type().Field(i)
if strings.HasPrefix(valueField.Name, "XXX_") {
continue
}
// IsNil will panic on most value kinds.
switch value.Kind() {
case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice:
if value.IsNil() {
continue
}
}
if !m.EmitDefaults {
switch value.Kind() {
case reflect.Bool:
if !value.Bool() {
continue
}
case reflect.Int32, reflect.Int64:
if value.Int() == 0 {
continue
}
case reflect.Uint32, reflect.Uint64:
if value.Uint() == 0 {
continue
}
case reflect.Float32, reflect.Float64:
if value.Float() == 0 {
continue
}
case reflect.String:
if value.Len() == 0 {
continue
}
}
}
// Oneof fields need special handling.
if valueField.Tag.Get("protobuf_oneof") != "" {
// value is an interface containing &T{real_value}.
sv := value.Elem().Elem() // interface -> *T -> T
value = sv.Field(0)
valueField = sv.Type().Field(0)
}
prop := jsonProperties(valueField, m.OrigName)
if !firstField {
m.writeSep(out)
}
// If the map value is a cast type, it may not implement proto.Message, therefore
// allow the struct tag to declare the underlying message type. Instead of changing
// the signatures of the child types (and because prop.mvalue is not public), use
// CustomType as a passer.
if value.Kind() == reflect.Map {
if tag := valueField.Tag.Get("protobuf"); tag != "" {
for _, v := range strings.Split(tag, ",") {
if !strings.HasPrefix(v, "castvaluetype=") {
continue
}
v = strings.TrimPrefix(v, "castvaluetype=")
prop.CustomType = v
break
}
}
}
if err := m.marshalField(out, prop, value, indent); err != nil {
return err
}
firstField = false
}
// Handle proto2 extensions.
if ep, ok := v.(proto.Message); ok {
extensions := proto.RegisteredExtensions(v)
// Sort extensions for stable output.
ids := make([]int32, 0, len(extensions))
for id, desc := range extensions {
if !proto.HasExtension(ep, desc) {
continue
}
ids = append(ids, id)
}
sort.Sort(int32Slice(ids))
for _, id := range ids {
desc := extensions[id]
if desc == nil {
// unknown extension
continue
}
ext, extErr := proto.GetExtension(ep, desc)
if extErr != nil {
return extErr
}
value := reflect.ValueOf(ext)
var prop proto.Properties
prop.Parse(desc.Tag)
prop.JSONName = fmt.Sprintf("[%s]", desc.Name)
if !firstField {
m.writeSep(out)
}
if err := m.marshalField(out, &prop, value, indent); err != nil {
return err
}
firstField = false
}
}
if m.Indent != "" {
out.write("\n")
out.write(indent)
}
out.write("}")
return out.err
}