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// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package xml_test
import (
"encoding/xml"
"fmt"
"log"
"strings"
)
type Animal int
const (
Unknown Animal = iota
Gopher
Zebra
)
func (a *Animal) UnmarshalXML(d *xml.Decoder, start xml.StartElement) error {
var s string
if err := d.DecodeElement(&s, &start); err != nil {
return err
}
switch strings.ToLower(s) {
default:
*a = Unknown
case "gopher":
*a = Gopher
case "zebra":
*a = Zebra
}
return nil
}
func (a Animal) MarshalXML(e *xml.Encoder, start xml.StartElement) error {
var s string
switch a {
default:
s = "unknown"
case Gopher:
s = "gopher"
case Zebra:
s = "zebra"
}
return e.EncodeElement(s, start)
}
func Example_customMarshalXML() {
blob := `
<animals>
<animal>gopher</animal>
<animal>armadillo</animal>
<animal>zebra</animal>
<animal>unknown</animal>
<animal>gopher</animal>
<animal>bee</animal>
<animal>gopher</animal>
<animal>zebra</animal>
</animals>`
var zoo struct {
Animals []Animal `xml:"animal"`
}
if err := xml.Unmarshal([]byte(blob), &zoo); err != nil {
log.Fatal(err)
}
census := make(map[Animal]int)
for _, animal := range zoo.Animals {
census[animal] += 1
}
fmt.Printf("Zoo Census:\n* Gophers: %d\n* Zebras: %d\n* Unknown: %d\n",
census[Gopher], census[Zebra], census[Unknown])
// Output:
// Zoo Census:
// * Gophers: 3
// * Zebras: 2
// * Unknown: 3
}
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