Golang中缺少Xml标签

Question

I am new to golang I am trying to make a xml in which i am using nested tags

For that my code is

type MyXml struct {
    XMLName xml.Name `xml:"myXml"`
    Id      int      `xml:"id,attr"`
    NewXml
}
type NewXml struct {
    XMLName xml.Name `xml:"newXml"`
    OneMoreXml
}

type OneMoreXml struct {
    Msg interface{} `xml:"oneMore"`
}

type Child struct {
    Param1 string `xml:"Param1"`
}

func main() {

    baseXml := &Child{Param1: "Param1"}
    retXml := GetXml(baseXml)
    fmt.Println("my xml is", retXml)

}
func MarshallXml(reqString interface{}) (newXml string) {
    xmlBody, err := xml.Marshal(reqString)
    if err != nil {
        fmt.Printf("error: %v
", err)
    }
    newXml = string(xmlBody)
    //fmt.Println(newXml)
    return
}
func GetXml(baseXml interface{}) (finalXml string) {

    startXml := new(MyXml)
    startXml.Id = 1
    startXml.Msg = baseXml
    finalXml = MarshallXml(startXml)
    return

}

but in my output xml Tag newXml is missing. I have tried it in various ways but some tag is always missing. I guess i am not understanding struct tag properly. So What i am doing wrong in above code and which basic concept of golang struct i am missing

Answer 1

I had a look at the xml package doc and they say that "an anonymous struct field is handled as if the fields of its value were part of the outer struct". In your case, all fields thus get serialized as if they were part of MyXml.

NewXml does not have any field (you just give it a name but there is nothing else) so nothing gets serialized for it. If you add a new field to it, you can see that it is serialized.

type NewXml struct {
    XMLName xml.Name `xml:"newXml"`
    Test    int
    OneMoreXml
}

http://play.golang.org/p/vibSeQHTCr