Function SetExtension

proto/extensions.go:223–249

SetExtension sets an extension field in m to the provided value.

(m Message, xt *ExtensionDesc, v interface{})

// SetExtension sets an extension field in m to the provided value.
func SetExtension(m Message, xt *ExtensionDesc, v interface{}) error {
	mr := MessageReflect(m)
	if mr == nil || !mr.IsValid() || mr.Descriptor().ExtensionRanges().Len() == 0 {
		return errNotExtendable
	}

	rv := reflect.ValueOf(v)
	if reflect.TypeOf(v) != reflect.TypeOf(xt.ExtensionType) {
		return fmt.Errorf("proto: bad extension value type. got: %T, want: %T", v, xt.ExtensionType)
	}
	if rv.Kind() == reflect.Ptr {
		if rv.IsNil() {
			return fmt.Errorf("proto: SetExtension called with nil value of type %T", v)
		}
		if isScalarKind(rv.Elem().Kind()) {
			v = rv.Elem().Interface()
		}
	}

	xtd := xt.TypeDescriptor()
	if !isValidExtension(mr.Descriptor(), xtd) {
		return fmt.Errorf("proto: bad extended type; %T does not extend %T", xt.ExtendedType, m)
	}
	mr.Set(xtd, xt.ValueOf(v))
	clearUnknown(mr, fieldNum(xt.Field))
	return nil
}

// SetRawExtension inserts b into the unknown fields of m.
//