|
|
@@ -0,0 +1,118 @@
|
|
|
+package null
|
|
|
+
|
|
|
+import (
|
|
|
+ "database/sql"
|
|
|
+ "encoding/json"
|
|
|
+ "fmt"
|
|
|
+ "reflect"
|
|
|
+ "strconv"
|
|
|
+)
|
|
|
+
|
|
|
+// Int is an nullable int64.
|
|
|
+// It does not consider zero values to be null.
|
|
|
+// It will decode to null, not zero, if null.
|
|
|
+type Int struct {
|
|
|
+ sql.NullInt64
|
|
|
+}
|
|
|
+
|
|
|
+// NewInt creates a new Int
|
|
|
+func NewInt(i int64, valid bool) Int {
|
|
|
+ return Int{
|
|
|
+ NullInt64: sql.NullInt64{
|
|
|
+ Int64: i,
|
|
|
+ Valid: valid,
|
|
|
+ },
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+// IntFrom creates a new Int that will always be valid.
|
|
|
+func IntFrom(i int64) Int {
|
|
|
+ return NewInt(i, true)
|
|
|
+}
|
|
|
+
|
|
|
+// IntFromPtr creates a new Int that be null if i is nil.
|
|
|
+func IntFromPtr(i *int64) Int {
|
|
|
+ if i == nil {
|
|
|
+ return NewInt(0, false)
|
|
|
+ }
|
|
|
+ return NewInt(*i, true)
|
|
|
+}
|
|
|
+
|
|
|
+// UnmarshalJSON implements json.Unmarshaler.
|
|
|
+// It supports number and null input.
|
|
|
+// 0 will not be considered a null Int.
|
|
|
+// It also supports unmarshalling a sql.NullInt64.
|
|
|
+func (i *Int) UnmarshalJSON(data []byte) error {
|
|
|
+ var err error
|
|
|
+ var v interface{}
|
|
|
+ if err = json.Unmarshal(data, &v); err != nil {
|
|
|
+ return err
|
|
|
+ }
|
|
|
+ switch v.(type) {
|
|
|
+ case float64:
|
|
|
+ // Unmarshal again, directly to int64, to avoid intermediate float64
|
|
|
+ err = json.Unmarshal(data, &i.Int64)
|
|
|
+ case map[string]interface{}:
|
|
|
+ err = json.Unmarshal(data, &i.NullInt64)
|
|
|
+ case nil:
|
|
|
+ i.Valid = false
|
|
|
+ return nil
|
|
|
+ default:
|
|
|
+ err = fmt.Errorf("json: cannot unmarshal %v into Go value of type null.Int", reflect.TypeOf(v).Name())
|
|
|
+ }
|
|
|
+ i.Valid = err == nil
|
|
|
+ return err
|
|
|
+}
|
|
|
+
|
|
|
+// UnmarshalText implements encoding.TextUnmarshaler.
|
|
|
+// It will unmarshal to a null Int if the input is a blank or not an integer.
|
|
|
+// It will return an error if the input is not an integer, blank, or "null".
|
|
|
+func (i *Int) UnmarshalText(text []byte) error {
|
|
|
+ str := string(text)
|
|
|
+ if str == "" || str == "null" {
|
|
|
+ i.Valid = false
|
|
|
+ return nil
|
|
|
+ }
|
|
|
+ var err error
|
|
|
+ i.Int64, err = strconv.ParseInt(string(text), 10, 64)
|
|
|
+ i.Valid = err == nil
|
|
|
+ return err
|
|
|
+}
|
|
|
+
|
|
|
+// MarshalJSON implements json.Marshaler.
|
|
|
+// It will encode null if this Int is null.
|
|
|
+func (i Int) MarshalJSON() ([]byte, error) {
|
|
|
+ if !i.Valid {
|
|
|
+ return []byte("null"), nil
|
|
|
+ }
|
|
|
+ return []byte(strconv.FormatInt(i.Int64, 10)), nil
|
|
|
+}
|
|
|
+
|
|
|
+// MarshalText implements encoding.TextMarshaler.
|
|
|
+// It will encode a blank string if this Int is null.
|
|
|
+func (i Int) MarshalText() ([]byte, error) {
|
|
|
+ if !i.Valid {
|
|
|
+ return []byte{}, nil
|
|
|
+ }
|
|
|
+ return []byte(strconv.FormatInt(i.Int64, 10)), nil
|
|
|
+}
|
|
|
+
|
|
|
+// SetValid changes this Int's value and also sets it to be non-null.
|
|
|
+func (i *Int) SetValid(n int64) {
|
|
|
+ i.Int64 = n
|
|
|
+ i.Valid = true
|
|
|
+}
|
|
|
+
|
|
|
+// Ptr returns a pointer to this Int's value, or a nil pointer if this Int is null.
|
|
|
+func (i Int) Ptr() *int64 {
|
|
|
+ if !i.Valid {
|
|
|
+ return nil
|
|
|
+ }
|
|
|
+ return &i.Int64
|
|
|
+}
|
|
|
+
|
|
|
+// IsZero returns true for invalid Ints, for future omitempty support (Go 1.4?)
|
|
|
+// A non-null Int with a 0 value will not be considered zero.
|
|
|
+func (i Int) IsZero() bool {
|
|
|
+ return !i.Valid
|
|
|
+}
|