69 lines
1.7 KiB
Go
69 lines
1.7 KiB
Go
// Package jsonhooks adds hooks that are automatically called before JSON marshaling (PreMarshalJSON) and
|
|
// after JSON unmarshaling (PostUnmarshalJSON). It does not do so recursively.
|
|
package jsonhooks
|
|
|
|
import (
|
|
"encoding/json"
|
|
"reflect"
|
|
)
|
|
|
|
// Marshal wraps encoding/json.Marshal, calls v.PreMarshalJSON() if it exists
|
|
func Marshal(v interface{}) ([]byte, error) {
|
|
if ImplementsPreJSONMarshaler(v) {
|
|
err := v.(PreJSONMarshaler).PreMarshalJSON()
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
}
|
|
|
|
return json.Marshal(v)
|
|
}
|
|
|
|
// Unmarshal wraps encoding/json.Unmarshal, calls v.PostUnmarshalJSON() if it exists
|
|
func Unmarshal(data []byte, v interface{}) error {
|
|
err := json.Unmarshal(data, v)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if ImplementsPostJSONUnmarshaler(v) {
|
|
err := v.(PostJSONUnmarshaler).PostUnmarshalJSON()
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// PreJSONMarshaler infers support for the PreMarshalJSON pre-hook
|
|
type PreJSONMarshaler interface {
|
|
PreMarshalJSON() error
|
|
}
|
|
|
|
// ImplementsPreJSONMarshaler checks for support for the PreMarshalJSON pre-hook
|
|
func ImplementsPreJSONMarshaler(v interface{}) bool {
|
|
value := reflect.ValueOf(v)
|
|
if !value.IsValid() {
|
|
return false
|
|
}
|
|
|
|
_, ok := value.Interface().(PreJSONMarshaler)
|
|
return ok
|
|
}
|
|
|
|
// PostJSONUnmarshaler infers support for the PostUnmarshalJSON post-hook
|
|
type PostJSONUnmarshaler interface {
|
|
PostUnmarshalJSON() error
|
|
}
|
|
|
|
// ImplementsPostJSONUnmarshaler checks for support for the PostUnmarshalJSON post-hook
|
|
func ImplementsPostJSONUnmarshaler(v interface{}) bool {
|
|
value := reflect.ValueOf(v)
|
|
if value.Kind() == reflect.Ptr && value.IsNil() {
|
|
return false
|
|
}
|
|
|
|
_, ok := value.Interface().(PostJSONUnmarshaler)
|
|
return ok
|
|
}
|