xml - Golang 指定 xml 结构中的顶级标签

Question

所以我正在尝试将一些 xml 解码或解码为一个类型(我仍然不完全清楚区别是什么)，而且我似乎无法指定最外层的类型(在本例中为 <people> ) .当我尝试指定此标记时，Marshalled 值没有包含任何我期望的内容，而不是出现错误。您如何指定最外层的标记，为什么第二个赋值没有预期的行为？

package main

import "fmt"
import "encoding/xml"
import "log"

var data string = `
<people>
  <person>
    <id>46</id>
    <name>John Smith</name>
  </person>
  <person>
    <id>3007</id>
    <name>Joe Smith</name>
  </person>
</people>
`

type Person struct {
    Id int `xml:"id"`
    Name string `xml:"name"`
}

type People struct {
    PersonList []Person `xml:"person"`
}

type Response struct {
    PeopleItem People `xml:"people"`
}

func main() {
    // parsing People
    // cannot specify outermost tag <people></people>
    var people People
    err := xml.Unmarshal([]byte(data), &people)

    if err != nil {
        log.Fatal(err)
    }

    fmt.Println(people)
    // prints "{[{46 John Smith} {3007 Joe Smith}]}"
    // which is reasonable

    // attempting to parse entire response, yields struct of struct of empty slice
    var response Response
    err = xml.Unmarshal([]byte(data), &response)
    if err != nil {
        log.Fatal(err)
    }

    // response is struct of struct of empty array
    // why does this happen?
    fmt.Println(response)
    // why does this print "{{[]}}" ?
}

Answer 1

您可以在不修改传入数据的情况下执行此操作，您可以使用特殊的 XMLName xml.Name 字段来设置外部标记，然后使用 xml:",chardata"访问它的内容。

这是一个例子:Try it on the go playground

package main

import (
    "encoding/xml"
    "fmt"
)

type simpleInt struct {
    XMLName xml.Name `xml:"integer"`
    Int     int      `xml:",chardata"`
}

type simpleString struct {
    XMLName xml.Name `xml:"stringtag"`
    String  string   `xml:",chardata"`
}

type simpleBoolean struct {
    XMLName xml.Name `xml:"boolean"`
    Boolean bool     `xml:",chardata"`
}

func main() {

    bint := []byte("<integer>1138</integer>")
    bstring := []byte("<stringtag>Caimeo</stringtag>")
    btrue := []byte("<boolean>true</boolean>")
    bfalse := []byte("<boolean>false</boolean>")

    i := simpleInt{}
    xml.Unmarshal(bint, &i)
    fmt.Println(i, i.Int)

    s := simpleString{}
    xml.Unmarshal(bstring, &s)
    fmt.Println(s, s.String)

    m := simpleBoolean{}
    xml.Unmarshal(btrue, &m)
    fmt.Println(m, m.Boolean)

    xml.Unmarshal(bfalse, &m)
    fmt.Println(m, m.Boolean)
}