117 lines
2.3 KiB
Go
117 lines
2.3 KiB
Go
package null
|
|
|
|
import (
|
|
"bytes"
|
|
"database/sql/driver"
|
|
"encoding/json"
|
|
|
|
"gopkg.in/nullbio/null.v6/convert"
|
|
)
|
|
|
|
// String is a nullable string. It supports SQL and JSON serialization.
|
|
type String struct {
|
|
String string
|
|
Valid bool
|
|
}
|
|
|
|
// StringFrom creates a new String that will never be blank.
|
|
func StringFrom(s string) String {
|
|
return NewString(s, true)
|
|
}
|
|
|
|
// StringFromPtr creates a new String that be null if s is nil.
|
|
func StringFromPtr(s *string) String {
|
|
if s == nil {
|
|
return NewString("", false)
|
|
}
|
|
return NewString(*s, true)
|
|
}
|
|
|
|
// NewString creates a new String
|
|
func NewString(s string, valid bool) String {
|
|
return String{
|
|
String: s,
|
|
Valid: valid,
|
|
}
|
|
}
|
|
|
|
// UnmarshalJSON implements json.Unmarshaler.
|
|
func (s *String) UnmarshalJSON(data []byte) error {
|
|
if bytes.Equal(data, NullBytes) {
|
|
s.String = ""
|
|
s.Valid = false
|
|
return nil
|
|
}
|
|
|
|
if err := json.Unmarshal(data, &s.String); err != nil {
|
|
return err
|
|
}
|
|
|
|
s.Valid = true
|
|
return nil
|
|
}
|
|
|
|
// MarshalJSON implements json.Marshaler.
|
|
func (s String) MarshalJSON() ([]byte, error) {
|
|
if !s.Valid {
|
|
return NullBytes, nil
|
|
}
|
|
return json.Marshal(s.String)
|
|
}
|
|
|
|
// MarshalText implements encoding.TextMarshaler.
|
|
func (s String) MarshalText() ([]byte, error) {
|
|
if !s.Valid {
|
|
return []byte{}, nil
|
|
}
|
|
return []byte(s.String), nil
|
|
}
|
|
|
|
// UnmarshalText implements encoding.TextUnmarshaler.
|
|
func (s *String) UnmarshalText(text []byte) error {
|
|
if text == nil || len(text) == 0 {
|
|
s.Valid = false
|
|
return nil
|
|
}
|
|
|
|
s.String = string(text)
|
|
s.Valid = true
|
|
return nil
|
|
}
|
|
|
|
// SetValid changes this String's value and also sets it to be non-null.
|
|
func (s *String) SetValid(v string) {
|
|
s.String = v
|
|
s.Valid = true
|
|
}
|
|
|
|
// Ptr returns a pointer to this String's value, or a nil pointer if this String is null.
|
|
func (s String) Ptr() *string {
|
|
if !s.Valid {
|
|
return nil
|
|
}
|
|
return &s.String
|
|
}
|
|
|
|
// IsNull returns true for null strings, for potential future omitempty support.
|
|
func (s String) IsNull() bool {
|
|
return !s.Valid
|
|
}
|
|
|
|
// Scan implements the Scanner interface.
|
|
func (s *String) Scan(value interface{}) error {
|
|
if value == nil {
|
|
s.String, s.Valid = "", false
|
|
return nil
|
|
}
|
|
s.Valid = true
|
|
return convert.ConvertAssign(&s.String, value)
|
|
}
|
|
|
|
// Value implements the driver Valuer interface.
|
|
func (s String) Value() (driver.Value, error) {
|
|
if !s.Valid {
|
|
return nil, nil
|
|
}
|
|
return s.String, nil
|
|
}
|