lbry.go/extras/null/time.go

123 lines
2.4 KiB
Go

package null
import (
"bytes"
"database/sql/driver"
"fmt"
"time"
)
// Time is a nullable time.Time. It supports SQL and JSON serialization.
type Time struct {
Time time.Time
Valid bool
}
// NewTime creates a new Time.
func NewTime(t time.Time, valid bool) Time {
return Time{
Time: t,
Valid: valid,
}
}
// TimeFrom creates a new Time that will always be valid.
func TimeFrom(t time.Time) Time {
return NewTime(t, true)
}
// TimeFromPtr creates a new Time that will be null if t is nil.
func TimeFromPtr(t *time.Time) Time {
if t == nil {
return NewTime(time.Time{}, false)
}
return NewTime(*t, true)
}
// MarshalJSON implements json.Marshaler.
func (t Time) MarshalJSON() ([]byte, error) {
if !t.Valid {
return NullBytes, nil
}
return t.Time.MarshalJSON()
}
// UnmarshalJSON implements json.Unmarshaler.
func (t *Time) UnmarshalJSON(data []byte) error {
if bytes.Equal(data, NullBytes) {
t.Valid = false
t.Time = time.Time{}
return nil
}
if err := t.Time.UnmarshalJSON(data); err != nil {
return err
}
t.Valid = true
return nil
}
// MarshalText implements encoding.TextMarshaler.
func (t Time) MarshalText() ([]byte, error) {
if !t.Valid {
return NullBytes, nil
}
return t.Time.MarshalText()
}
// UnmarshalText implements encoding.TextUnmarshaler.
func (t *Time) UnmarshalText(text []byte) error {
if text == nil || len(text) == 0 {
t.Valid = false
return nil
}
if err := t.Time.UnmarshalText(text); err != nil {
return err
}
t.Valid = true
return nil
}
// SetValid changes this Time's value and sets it to be non-null.
func (t *Time) SetValid(v time.Time) {
t.Time = v
t.Valid = true
}
// Ptr returns a pointer to this Time's value, or a nil pointer if this Time is null.
func (t Time) Ptr() *time.Time {
if !t.Valid {
return nil
}
return &t.Time
}
// IsNull returns true for invalid Times, for future omitempty support (Go 1.4?)
func (t Time) IsNull() bool {
return !t.Valid
}
// Scan implements the Scanner interface.
func (t *Time) Scan(value interface{}) error {
var err error
switch x := value.(type) {
case time.Time:
t.Time = x
case nil:
t.Valid = false
return nil
default:
err = fmt.Errorf("null: cannot scan type %T into null.Time: %v", value, value)
}
t.Valid = err == nil
return err
}
// Value implements the driver Valuer interface.
func (t Time) Value() (driver.Value, error) {
if !t.Valid {
return nil, nil
}
return t.Time, nil
}