如何从xml的根元素获取第一级注释

Question

my xsd file has following structure:

<?xml version="1.0" encoding="UTF-8"?>
<!-- EIS docs-ws-api Integration Scheme, version 6.4, create date 15.11.2016 -->
<someTag></someTag>

how to get this comment? i try did it on playground https://play.golang.org/p/PVHux_Gvb7

Answer 1

As mentioned in other answer, xml.Unmarshal can parse comment only if it's part of XML element.

External library xmlpath which implements XPath specification can be useful in your case.

Install: go get gopkg.in/xmlpath.v1

Let's extract preceding comment of tag named someTag from your example xml.

import (
    "fmt"
    "log"

    "strings"

    xmlpath "gopkg.in/xmlpath.v1"
)

func main() {
    data := `
<?xml version="1.0" encoding="UTF-8"?>
<!-- EIS docs-ws-api Integration Scheme, version 6.4, create date 15.11.2016 -->
<someTag></someTag>
`
    path := xmlpath.MustCompile("/someTag/preceding::comment()")
    root, err := xmlpath.Parse(strings.NewReader(data))
    if err != nil {
        log.Fatal(err)
    }
    if comment, ok := path.String(root); ok {
        fmt.Println(comment)
    }
}