123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171 |
- // Copyright (C) 2023 The Syncthing Authors.
- //
- // This Source Code Form is subject to the terms of the Mozilla Public
- // License, v. 2.0. If a copy of the MPL was not distributed with this file,
- // You can obtain one at https://mozilla.org/MPL/2.0/.
- package structutil
- import (
- "reflect"
- "strconv"
- "strings"
- )
- type defaultParser interface {
- ParseDefault(string) error
- }
- // SetDefaults sets default values on a struct, based on the default annotation.
- func SetDefaults(data any) {
- s := reflect.ValueOf(data).Elem()
- t := s.Type()
- for i := 0; i < s.NumField(); i++ {
- f := s.Field(i)
- tag := t.Field(i).Tag
- v := tag.Get("default")
- if len(v) > 0 {
- if f.CanInterface() {
- if parser, ok := f.Interface().(defaultParser); ok {
- if err := parser.ParseDefault(v); err != nil {
- panic(err)
- }
- continue
- }
- }
- if f.CanAddr() && f.Addr().CanInterface() {
- if parser, ok := f.Addr().Interface().(defaultParser); ok {
- if err := parser.ParseDefault(v); err != nil {
- panic(err)
- }
- continue
- }
- }
- switch f.Interface().(type) {
- case string:
- f.SetString(v)
- case int, uint32, int32, int64, uint64:
- i, err := strconv.ParseInt(v, 10, 64)
- if err != nil {
- panic(err)
- }
- f.SetInt(i)
- case float64, float32:
- i, err := strconv.ParseFloat(v, 64)
- if err != nil {
- panic(err)
- }
- f.SetFloat(i)
- case bool:
- f.SetBool(v == "true")
- case []string:
- // We don't do anything with string slices here. Any default
- // we set will be appended to by the XML decoder, so we fill
- // those after decoding.
- default:
- panic(f.Type())
- }
- } else if f.CanSet() && f.Kind() == reflect.Struct && f.CanAddr() {
- if addr := f.Addr(); addr.CanInterface() {
- SetDefaults(addr.Interface())
- }
- }
- }
- }
- func FillNilExceptDeprecated(data any) {
- fillNil(data, true)
- }
- func FillNil(data any) {
- fillNil(data, false)
- }
- func fillNil(data any, skipDeprecated bool) {
- s := reflect.ValueOf(data).Elem()
- t := s.Type()
- for i := 0; i < s.NumField(); i++ {
- if skipDeprecated && strings.HasPrefix(t.Field(i).Name, "Deprecated") {
- continue
- }
- f := s.Field(i)
- for f.Kind() == reflect.Ptr && f.IsZero() && f.CanSet() {
- newValue := reflect.New(f.Type().Elem())
- f.Set(newValue)
- f = f.Elem()
- }
- if f.CanSet() {
- if f.IsZero() {
- switch f.Kind() {
- case reflect.Map:
- f.Set(reflect.MakeMap(f.Type()))
- case reflect.Slice:
- f.Set(reflect.MakeSlice(f.Type(), 0, 0))
- case reflect.Chan:
- f.Set(reflect.MakeChan(f.Type(), 0))
- }
- }
- switch f.Kind() {
- case reflect.Slice:
- if f.Type().Elem().Kind() != reflect.Struct {
- continue
- }
- for i := 0; i < f.Len(); i++ {
- fillNil(f.Index(i).Addr().Interface(), skipDeprecated)
- }
- case reflect.Struct:
- if f.CanAddr() {
- if addr := f.Addr(); addr.CanInterface() {
- fillNil(addr.Interface(), skipDeprecated)
- }
- }
- }
- }
- }
- }
- // FillNilSlices sets default value on slices that are still nil.
- func FillNilSlices(data any) error {
- s := reflect.ValueOf(data).Elem()
- t := s.Type()
- for i := 0; i < s.NumField(); i++ {
- f := s.Field(i)
- tag := t.Field(i).Tag
- v := tag.Get("default")
- if len(v) > 0 {
- switch f.Interface().(type) {
- case []string:
- if f.IsNil() {
- // Treat the default as a comma separated slice
- vs := strings.Split(v, ",")
- for i := range vs {
- vs[i] = strings.TrimSpace(vs[i])
- }
- rv := reflect.MakeSlice(reflect.TypeOf([]string{}), len(vs), len(vs))
- for i, v := range vs {
- rv.Index(i).SetString(v)
- }
- f.Set(rv)
- }
- }
- }
- }
- return nil
- }
|