在GO中解析Xml以获取标记中带有“：”的属性

Question

I want to parse the attribute of an Xml file. It works for any "normal" attributes like for instance <application name="AppName">

But I can't manage to retrieve the value of the attribute if it has a ":" in it., like <application name:test="AppName">

Here is the code that I am using to parse this :

package main

import "fmt"
import "encoding/xml"

type Application struct {
    Event Event `xml:"application"`
    Package   string    `xml:"package,attr"`
}

type Event struct {
    IsValid   string `xml:"test:isValid,attr"`
}

var doc = []byte(`<?xml version="1.0" encoding="utf-8" standalone="no"?>
    <application package="leNomDuPackage">
            <event test:isValid="true">
        </application>
</manifest>`)

func main() {
    application := Application{}
    xml.Unmarshal(doc, &application)

    fmt.Println("Application:  ", application)
    fmt.Println("isValid:", application.Event)
}

You can find it on the Golang playground as well : [https://play.golang.org/p/R6H80xPezhm

I want to retrieve the value of the isValid attribute.

At the moment, I have that error message and I can't manage to solve it.

struct field tag xml:"test\:isValid,attr not compatible with reflect.StructTag.Get: bad syntax for struct tag value

I tried as well with the following value of

type Event struct {
    IsValid   string `xml:"test isValid,attr`
}

and

type Event struct {
    IsValid   string `xml:"test\:isValid,attr`
}

But it is not working as well.

Answer 1

You can leave out the "test:" prefix in the tag definition. Just make sure your XML is valid, yours don't have a closing tag for <event> and has an unmatched closing tag </manifest>. You're also missing a closing quotation mark in the tag definition.

Model:

type Application struct {
    Event   Event  `xml:"event"`
    Package string `xml:"package,attr"`
}

type Event struct {
    IsValid string `xml:"isValid,attr"`
}

A valid XML example:

var doc = `
<application package="leNomDuPackage">
    <event test:isValid="true" />
</application>`

Code parsing it:

application := Application{}
err := xml.Unmarshal([]byte(doc), &application)
if err != nil {
    fmt.Println(err)
}

fmt.Printf("Application: %#v
", application)

Output (try it on the Go Playground):

Application: main.Application{Event:main.Event{IsValid:"true"},
    Package:"leNomDuPackage"}

Note that if you have multiple attributes with the same name but different prefixes, such as this example:

var doc = `
<application package="leNomDuPackage">
    <event test:isValid="true" test2:isValid="false" />
</application>`

Then you may add the namespace prefix in the tag value, separated by a space from the name, like this:

type Event struct {
    IsValid1 string `xml:"test isValid,attr"`
    IsValid2 string `xml:"test2 isValid,attr"`
}

Parsing code is the same. Output (try it on the Go Playground):

Application: main.Application{Event:main.Event{IsValid1:"true", 
    IsValid2:"false"}, Package:"leNomDuPackage"}