package extra import ( "github.com/json-iterator/go" "strings" "unicode" ) // SetNamingStrategy rename struct fields uniformly func SetNamingStrategy(translate func(string) string) { jsoniter.RegisterExtension(&namingStrategyExtension{jsoniter.DummyExtension{}, translate}) } type namingStrategyExtension struct { jsoniter.DummyExtension translate func(string) string } func (extension *namingStrategyExtension) UpdateStructDescriptor(structDescriptor *jsoniter.StructDescriptor) { for _, binding := range structDescriptor.Fields { tag, hastag := binding.Field.Tag().Lookup("json") if hastag { tagParts := strings.Split(tag, ",") if tagParts[0] == "-" { continue // hidden field } if tagParts[0] != "" { continue // field explicitly named } } binding.ToNames = []string{extension.translate(binding.Field.Name())} binding.FromNames = []string{extension.translate(binding.Field.Name())} } } // LowerCaseWithUnderscores one strategy to SetNamingStrategy for. It will change HelloWorld to hello_world. func LowerCaseWithUnderscores(name string) string { newName := []rune{} for i, c := range name { if i == 0 { newName = append(newName, unicode.ToLower(c)) } else { if unicode.IsUpper(c) { newName = append(newName, '_') newName = append(newName, unicode.ToLower(c)) } else { newName = append(newName, c) } } } return string(newName) }