go-json/internal/runtime/struct_field.go

88 lines
1.6 KiB
Go

package runtime
import (
"reflect"
"strings"
"unicode"
)
func getTag(field reflect.StructField) string {
return field.Tag.Get("json")
}
func IsIgnoredStructField(field reflect.StructField) bool {
if field.PkgPath != "" {
if field.Anonymous {
if !(field.Type.Kind() == reflect.Ptr && field.Type.Elem().Kind() == reflect.Struct) && field.Type.Kind() != reflect.Struct {
return true
}
} else {
// private field
return true
}
}
tag := getTag(field)
return tag == "-"
}
type StructTag struct {
Key string
IsTaggedKey bool
IsOmitEmpty bool
IsString bool
Field reflect.StructField
}
type StructTags []*StructTag
func (t StructTags) ExistsKey(key string) bool {
for _, tt := range t {
if tt.Key == key {
return true
}
}
return false
}
func isValidTag(s string) bool {
if s == "" {
return false
}
for _, c := range s {
switch {
case strings.ContainsRune("!#$%&()*+-./:<=>?@[]^_{|}~ ", c):
// Backslash and quote chars are reserved, but
// otherwise any punctuation chars are allowed
// in a tag name.
case !unicode.IsLetter(c) && !unicode.IsDigit(c):
return false
}
}
return true
}
func StructTagFromField(field reflect.StructField) *StructTag {
keyName := field.Name
tag := getTag(field)
st := &StructTag{Field: field}
opts := strings.Split(tag, ",")
if len(opts) > 0 {
if opts[0] != "" && isValidTag(opts[0]) {
keyName = opts[0]
st.IsTaggedKey = true
}
}
st.Key = keyName
if len(opts) > 1 {
for _, opt := range opts[1:] {
switch opt {
case "omitempty":
st.IsOmitEmpty = true
case "string":
st.IsString = true
}
}
}
return st
}