Go中的通用XML解析器

Question

Is there some general approach of reading XML document in Go? Something similar to XmlDocument or XDocument in C#?

All the examples I found show how to read using unmarshaling functionality into the objects I need to define, but it's quite time consuming as I need to define a lot of staff that I'm not going to use.

xml.Unmarshal(...)

Another approach is forward only reading using:

xml.NewDecoder(xmlFile) 

Described here: http://blog.davidsingleton.org/parsing-huge-xml-files-with-go/

Answer 1

All the examples I found show how to read using unmarshaling functionality into the objects I need to define, but it's quite time consuming as I need to define a lot of staff that I'm not going to use.

Then don't define what you're not going to use, define only what you're going to use. You don't have to create a Go model that perfectly covers the XML structure.

Let's assume you have an XML like this:

<blog id="1234">
    <meta keywords="xml,parsing,partial" />
    <name>Partial XML parsing</name>
    <url>http://somehost.com/xml-blog</url>
    <entries count="2">
        <entry time="2016-01-19 08:40:00">
            <author>Bob</author>
            <content>First entry</content>
        </entry>
        <entry time="2016-01-19 08:30:00">
            <author>Alice</author>
            <content>Second entry</content>
        </entry>
    </entries>
</blog>

And let's assume you only need the following info out of this XML:

• id
• keywords
• blog name
• authors names

You can model these wanted pieces of information with the following struct:

type Data struct {
    Id   string `xml:"id,attr"`
    Meta struct {
        Keywords string `xml:"keywords,attr"`
    } `xml:"meta"`
    Name    string   `xml:"name"`
    Authors []string `xml:"entries>entry>author"`
}

And now you can parse only these information with the following code:

d := Data{}
if err := xml.Unmarshal([]byte(s), &d); err != nil {
    panic(err)
}
fmt.Printf("%+v", d)

Output (try it on the Go Playground):

{Id:1234 Meta:{Keywords:xml,parsing,partial} Name:Partial XML parsing Authors:[Bob Alice]}