146 lines
3.3 KiB
Go
146 lines
3.3 KiB
Go
package zero
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import (
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"database/sql/driver"
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"encoding/json"
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"fmt"
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"reflect"
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"strconv"
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"gopkg.in/nullbio/null.v4/convert"
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)
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type NullInt32 struct {
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Int32 int32
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Valid bool
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}
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// Int32 is a nullable int32.
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// JSON marshals to zero if null.
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// Considered null to SQL if zero.
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type Int32 struct {
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NullInt32
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}
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// NewInt32 creates a new Int32
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func NewInt32(i int32, valid bool) Int32 {
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return Int32{
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NullInt32: NullInt32{
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Int32: i,
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Valid: valid,
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},
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}
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}
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// Int32From creates a new Int32 that will be null if zero.
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func Int32From(i int32) Int32 {
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return NewInt32(i, i != 0)
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}
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// Int32FromPtr creates a new Int32 that be null if i is nil.
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func Int32FromPtr(i *int32) Int32 {
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if i == nil {
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return NewInt32(0, false)
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}
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n := NewInt32(*i, true)
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return n
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}
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// UnmarshalJSON implements json.Unmarshaler.
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// It supports number and null input.
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// 0 will be considered a null Int32.
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// It also supports unmarshalling a sql.NullInt32.
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func (i *Int32) UnmarshalJSON(data []byte) error {
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var err error
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var v interface{}
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if err = json.Unmarshal(data, &v); err != nil {
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return err
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}
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switch v.(type) {
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case float64:
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// Unmarshal again, directly to int32, to avoid intermediate float64
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err = json.Unmarshal(data, &i.Int32)
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case map[string]interface{}:
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err = json.Unmarshal(data, &i.NullInt32)
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case nil:
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i.Valid = false
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return nil
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default:
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err = fmt.Errorf("json: cannot unmarshal %v into Go value of type zero.Int32", reflect.TypeOf(v).Name())
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}
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i.Valid = (err == nil) && (i.Int32 != 0)
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return err
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}
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// UnmarshalText implements encoding.TextUnmarshaler.
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// It will unmarshal to a null Int32 if the input is a blank, zero, or not an integer.
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// It will return an error if the input is not an integer, blank, or "null".
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func (i *Int32) UnmarshalText(text []byte) error {
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str := string(text)
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if str == "" || str == "null" {
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i.Valid = false
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return nil
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}
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var err error
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res, err := strconv.ParseInt(string(text), 10, 32)
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i.Int32 = int32(res)
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i.Valid = (err == nil) && (i.Int32 != 0)
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return err
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}
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// MarshalJSON implements json.Marshaler.
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// It will encode 0 if this Int32 is null.
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func (i Int32) MarshalJSON() ([]byte, error) {
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n := i.Int32
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if !i.Valid {
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n = 0
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}
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return []byte(strconv.FormatInt(int64(n), 10)), nil
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}
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// MarshalText implements encoding.TextMarshaler.
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// It will encode a zero if this Int32 is null.
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func (i Int32) MarshalText() ([]byte, error) {
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n := i.Int32
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if !i.Valid {
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n = 0
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}
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return []byte(strconv.FormatInt(int64(n), 10)), nil
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}
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// SetValid changes this Int32's value and also sets it to be non-null.
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func (i *Int32) SetValid(n int32) {
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i.Int32 = n
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i.Valid = true
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}
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// Ptr returns a pointer to this Int32's value, or a nil pointer if this Int32 is null.
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func (i Int32) Ptr() *int32 {
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if !i.Valid {
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return nil
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}
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return &i.Int32
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}
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// IsZero returns true for null or zero Int32s, for future omitempty support (Go 1.4?)
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func (i Int32) IsZero() bool {
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return !i.Valid || i.Int32 == 0
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}
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// Scan implements the Scanner interface.
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func (n *NullInt32) Scan(value interface{}) error {
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if value == nil {
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n.Int32, n.Valid = 0, false
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return nil
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}
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n.Valid = true
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return convert.ConvertAssign(&n.Int32, value)
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}
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// Value implements the driver Valuer interface.
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func (n NullInt32) Value() (driver.Value, error) {
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if !n.Valid {
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return nil, nil
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}
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return int64(n.Int32), nil
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}
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