英文:
Parsing XML attributes with GO
问题
我对GO还不太熟悉，我在从XML文档中提取属性值方面遇到了一些问题。下面的代码产生了以下输出：
应用程序ID：""
应用程序名称：""
我猜想在使用标记时我可能遗漏了一些东西，如果有人能指点我正确的方向，我将不胜感激。
data:=<?xml version="1.0" encoding="UTF-8"?> <applist> <app app_id="1234" app_name="abc"/> <app app_id="5678" app_name="def"/> </applist>
type App struct {
app_id string xml:"app_id,attr"
app_name string xml:"app_name"
}
type AppList struct {
XMLName xml.Name xml:"applist"
Apps []App xml:"app"
}
var portfolio AppList
err := xml.Unmarshal([]byte(data), &portfolio)
if err != nil {
fmt.Printf("error: %v", err)
return
}
fmt.Printf("application ID:: %q\n", portfolio.Apps[0].app_id)
fmt.Printf("application name:: %q\n", portfolio.Apps[0].app_name)
英文:
I am pretty new to GO and I am having trouble extracting attribute values from XML documents. The code below produces the following output:
application ID:: ""
application name:: ""
My assumption is that I am missing something when it comes to how to use tagging and I would really appreciate it if someone could point me in the right direction.
data:=`<?xml version="1.0" encoding="UTF-8"?>
<applist>
<app app_id="1234" app_name="abc"/>
<app app_id="5678" app_name="def"/>
</applist> `
type App struct {
app_id string `xml:"app_id,attr"`
app_name string `xml:"app_name"`
}
type AppList struct {
XMLName xml.Name `xml:"applist"`
Apps []App `xml:"app"`
}
var portfolio AppList
err := xml.Unmarshal([]byte(data), &portfolio)
if err != nil {
fmt.Printf("error: %v", err)
return
}
fmt.Printf("application ID:: %q\n", portfolio.Apps[0].app_id)
fmt.Printf("application name:: %q\n", portfolio.Apps[0].app_name)
答案1
得分: 5
为了能够提取元素，你需要在App结构体中将app_id和app_name字段定义为"导出"字段，也就是说它们的首字母应该大写。此外，你的app_name字段在xml字段标签中还缺少了,attr。以下是你的代码的一个可工作示例，我已经在需要更改的行上添加了注释。
package main
import (
"fmt"
"encoding/xml"
)
func main() {
data := `
<?xml version="1.0" encoding="UTF-8"?>
<applist>
<app app_id="1234" app_name="abc"/>
<app app_id="5678" app_name="def"/>
</applist>
`
type App struct {
App_id string `xml:"app_id,attr"` // 注意这里的字段名首字母大写
App_name string `xml:"app_name,attr"` // 注意这里的字段名首字母大写和`xml:"app_name,attr"`
}
type AppList struct {
XMLName xml.Name `xml:"applist"`
Apps []App `xml:"app"`
}
var portfolio AppList
err := xml.Unmarshal([]byte(data), &portfolio)
if err != nil {
fmt.Printf("error: %v", err)
return
}
fmt.Printf("application ID: %q\n", portfolio.Apps[0].App_id) // 对应App的更改
fmt.Printf("application name: %q\n", portfolio.Apps[0].App_name) // 对应App的更改
}
希望对你有帮助！
英文:
In order to be able to get the elements out you have to have "exported" fields, meaning that app_id and app_name in the App struct should start with a capital letter. In addition, your app_name field is also missing a ,attr in its xml field tag. See below for a working example of your code. I've added comments on the lines that require some changes.
package main
import (
"fmt"
"encoding/xml"
)
func main() {
data:=`
<?xml version="1.0" encoding="UTF-8"?>
<applist>
<app app_id="1234" app_name="abc"/>
<app app_id="5678" app_name="def"/>
</applist>
`
type App struct {
App_id string `xml:"app_id,attr"` // notice the capitalized field name here
App_name string `xml:"app_name,attr"` // notice the capitalized field name here and the `xml:"app_name,attr"`
}
type AppList struct {
XMLName xml.Name `xml:"applist"`
Apps []App `xml:"app"`
}
var portfolio AppList
err := xml.Unmarshal([]byte(data), &portfolio)
if err != nil {
fmt.Printf("error: %v", err)
return
}
fmt.Printf("application ID:: %q\n", portfolio.Apps[0].App_id) // the corresponding changes here for App
fmt.Printf("application name:: %q\n", portfolio.Apps[0].App_name) // the corresponding changes here for App
}
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