129 lines
2.7 KiB
Go
129 lines
2.7 KiB
Go
package null
|
|
|
|
import (
|
|
"bytes"
|
|
"database/sql/driver"
|
|
"encoding/json"
|
|
|
|
"gopkg.in/nullbio/null.v5/convert"
|
|
)
|
|
|
|
// NullBytes is a global byte slice of JSON null
|
|
var NullBytes = []byte("null")
|
|
|
|
// Bytes is a nullable []byte.
|
|
type Bytes struct {
|
|
Bytes []byte
|
|
Valid bool
|
|
}
|
|
|
|
// NewBytes creates a new Bytes
|
|
func NewBytes(b []byte, valid bool) Bytes {
|
|
return Bytes{
|
|
Bytes: b,
|
|
Valid: valid,
|
|
}
|
|
}
|
|
|
|
// BytesFrom creates a new Bytes that will be invalid if nil.
|
|
func BytesFrom(b []byte) Bytes {
|
|
return NewBytes(b, b != nil)
|
|
}
|
|
|
|
// BytesFromPtr creates a new Bytes that will be invalid if nil.
|
|
func BytesFromPtr(b *[]byte) Bytes {
|
|
if b == nil {
|
|
return NewBytes(nil, false)
|
|
}
|
|
n := NewBytes(*b, true)
|
|
return n
|
|
}
|
|
|
|
// UnmarshalJSON implements json.Unmarshaler.
|
|
// If data is len 0 or nil, it will unmarshal to JSON null.
|
|
// If not, it will copy your data slice into Bytes.
|
|
func (b *Bytes) UnmarshalJSON(data []byte) error {
|
|
if bytes.Equal(data, NullBytes) {
|
|
b.Valid = false
|
|
b.Bytes = nil
|
|
return nil
|
|
}
|
|
|
|
var s string
|
|
if err := json.Unmarshal(data, &s); err != nil {
|
|
return err
|
|
}
|
|
|
|
b.Bytes = []byte(s)
|
|
b.Valid = true
|
|
return nil
|
|
}
|
|
|
|
// UnmarshalText implements encoding.TextUnmarshaler.
|
|
// It will unmarshal to nil if the text is nil or len 0.
|
|
func (b *Bytes) UnmarshalText(text []byte) error {
|
|
if text == nil || len(text) == 0 {
|
|
b.Bytes = nil
|
|
b.Valid = false
|
|
} else {
|
|
b.Bytes = append(b.Bytes[0:0], text...)
|
|
b.Valid = true
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// MarshalJSON implements json.Marshaler.
|
|
// It will encode null if the Bytes is nil.
|
|
func (b Bytes) MarshalJSON() ([]byte, error) {
|
|
if len(b.Bytes) == 0 || b.Bytes == nil {
|
|
return []byte("null"), nil
|
|
}
|
|
return b.Bytes, nil
|
|
}
|
|
|
|
// MarshalText implements encoding.TextMarshaler.
|
|
// It will encode nil if the Bytes is invalid.
|
|
func (b Bytes) MarshalText() ([]byte, error) {
|
|
if !b.Valid {
|
|
return nil, nil
|
|
}
|
|
return b.Bytes, nil
|
|
}
|
|
|
|
// SetValid changes this Bytes's value and also sets it to be non-null.
|
|
func (b *Bytes) SetValid(n []byte) {
|
|
b.Bytes = n
|
|
b.Valid = true
|
|
}
|
|
|
|
// Ptr returns a pointer to this Bytes's value, or a nil pointer if this Bytes is null.
|
|
func (b Bytes) Ptr() *[]byte {
|
|
if !b.Valid {
|
|
return nil
|
|
}
|
|
return &b.Bytes
|
|
}
|
|
|
|
// IsZero returns true for null or zero Bytes's, for future omitempty support (Go 1.4?)
|
|
func (b Bytes) IsZero() bool {
|
|
return !b.Valid
|
|
}
|
|
|
|
// Scan implements the Scanner interface.
|
|
func (b *Bytes) Scan(value interface{}) error {
|
|
if value == nil {
|
|
b.Bytes, b.Valid = []byte{}, false
|
|
return nil
|
|
}
|
|
b.Valid = true
|
|
return convert.ConvertAssign(&b.Bytes, value)
|
|
}
|
|
|
|
// Value implements the driver Valuer interface.
|
|
func (b Bytes) Value() (driver.Value, error) {
|
|
if !b.Valid {
|
|
return nil, nil
|
|
}
|
|
return b.Bytes, nil
|
|
}
|