Go offers built-in support for XML and XML-like
formats with the
encoding/xml
package. | |
|  package main
|
| import (
"encoding/xml"
"fmt"
)
|
Plant will be mapped to XML. Similarly to the
JSON examples, field tags contain directives for the
encoder and decoder. Here we use some special features
of the XML package: the
XMLName
field name dictates
the name of the XML element representing this struct;
id,attr
means that the
Id
field is an XML
attribute
rather than a nested element. | type Plant struct {
XMLName xml.Name `xml:"plant"`
Id int `xml:"id,attr"`
Name string `xml:"name"`
Origin []string `xml:"origin"`
}
|
| func (p Plant) String() string {
return fmt.Sprintf("Plant id=%v, name=%v, origin=%v",
p.Id, p.Name, p.Origin)
}
|
| func main() {
coffee := &Plant{Id: 27, Name: "Coffee"}
coffee.Origin = []string{"Ethiopia", "Brazil"}
|
Emit XML representing our plant; using
MarshalIndent
to produce a more
human-readable output. | out, _ := xml.MarshalIndent(coffee, " ", " ")
fmt.Println(string(out))
|
To add a generic XML header to the output, append
it explicitly. | fmt.Println(xml.Header + string(out))
|
Use
Unmarshal
to parse a stream of bytes with XML
into a data structure. If the XML is malformed or
cannot be mapped onto Plant, a descriptive error
will be returned. | var p Plant
if err := xml.Unmarshal(out, &p); err != nil {
panic(err)
}
fmt.Println(p)
|
| tomato := &Plant{Id: 81, Name: "Tomato"}
tomato.Origin = []string{"Mexico", "California"}
|
The
parent>child>plant
field tag tells the encoder
to nest all
plant
s under
<parent><child>... | type Nesting struct {
XMLName xml.Name `xml:"nesting"`
Plants []*Plant `xml:"parent>child>plant"`
}
|
| nesting := &Nesting{}
nesting.Plants = []*Plant{coffee, tomato}
|
| out, _ = xml.MarshalIndent(nesting, " ", " ")
fmt.Println(string(out))
}
|