lbry.go/bool.go
2016-11-11 01:00:05 +10:00

131 lines
2.4 KiB
Go

package null
import (
"bytes"
"database/sql/driver"
"encoding/json"
"errors"
"github.com/nullbio/null/convert"
)
// Bool is a nullable bool.
type Bool struct {
Bool bool
Valid bool
}
// NewBool creates a new Bool
func NewBool(b bool, valid bool) Bool {
return Bool{
Bool: b,
Valid: valid,
}
}
// BoolFrom creates a new Bool that will always be valid.
func BoolFrom(b bool) Bool {
return NewBool(b, true)
}
// BoolFromPtr creates a new Bool that will be null if f is nil.
func BoolFromPtr(b *bool) Bool {
if b == nil {
return NewBool(false, false)
}
return NewBool(*b, true)
}
// UnmarshalJSON implements json.Unmarshaler.
func (b *Bool) UnmarshalJSON(data []byte) error {
if bytes.Equal(data, NullBytes) {
b.Bool = false
b.Valid = false
return nil
}
if err := json.Unmarshal(data, &b.Bool); err != nil {
return err
}
b.Valid = true
return nil
}
// UnmarshalText implements encoding.TextUnmarshaler.
func (b *Bool) UnmarshalText(text []byte) error {
str := string(text)
switch str {
case "", "null":
b.Valid = false
return nil
case "true":
b.Bool = true
case "false":
b.Bool = false
default:
b.Valid = false
return errors.New("invalid input:" + str)
}
b.Valid = true
return nil
}
// MarshalJSON implements json.Marshaler.
func (b Bool) MarshalJSON() ([]byte, error) {
if !b.Valid {
return []byte("null"), nil
}
if !b.Bool {
return []byte("false"), nil
}
return []byte("true"), nil
}
// MarshalText implements encoding.TextMarshaler.
func (b Bool) MarshalText() ([]byte, error) {
if !b.Valid {
return []byte{}, nil
}
if !b.Bool {
return []byte("false"), nil
}
return []byte("true"), nil
}
// SetValid changes this Bool's value and also sets it to be non-null.
func (b *Bool) SetValid(v bool) {
b.Bool = v
b.Valid = true
}
// Ptr returns a pointer to this Bool's value, or a nil pointer if this Bool is null.
func (b Bool) Ptr() *bool {
if !b.Valid {
return nil
}
return &b.Bool
}
// IsZero returns true for invalid Bools, for future omitempty support (Go 1.4?)
func (b Bool) IsZero() bool {
return !b.Valid
}
// Scan implements the Scanner interface.
func (b *Bool) Scan(value interface{}) error {
if value == nil {
b.Bool, b.Valid = false, false
return nil
}
b.Valid = true
return convert.ConvertAssign(&b.Bool, value)
}
// Value implements the driver Valuer interface.
func (b Bool) Value() (driver.Value, error) {
if !b.Valid {
return nil, nil
}
return b.Bool, nil
}