null_decimal.go

package decimal

import "database/sql/driver"

// NullDecimal represents a nullable decimal with compatibility for
// scanning null values from the database.
type NullDecimal struct {
	Decimal Decimal
	Valid   bool
}

func NewNullDecimal(d Decimal) NullDecimal {
	return NullDecimal{
		Decimal: d,
		Valid:   true,
	}
}

// Scan implements the sql.Scanner interface for database deserialization.
func (d *NullDecimal) Scan(value interface{}) error {
	if value == nil {
		d.Valid = false
		return nil
	}
	d.Valid = true
	return d.Decimal.Scan(value)
}

// Value implements the driver.Valuer interface for database serialization.
func (d NullDecimal) Value() (driver.Value, error) {
	if !d.Valid {
		return nil, nil
	}
	return d.Decimal.Value()
}

// UnmarshalText implements the encoding.TextUnmarshaler interface for XML
// deserialization
func (d *NullDecimal) UnmarshalText(text []byte) error {
	str := string(text)

	// check for empty XML or XML without body e.g., <tag></tag>
	if str == "" {
		d.Valid = false
		return nil
	}
	if err := d.Decimal.UnmarshalText(text); err != nil {
		d.Valid = false
		return err
	}
	d.Valid = true
	return nil
}

// MarshalText implements the encoding.TextMarshaler interface for XML
// serialization.
func (d NullDecimal) MarshalText() (text []byte, err error) {
	if !d.Valid {
		return []byte{}, nil
	}
	return d.Decimal.MarshalText()
}