解析带有命名空间的 XML 标签 – Golang

huangapple
go评论105阅读模式
英文:

Unmarshal namespaced XML tags - Golang

问题

我正在尝试从一个.odt文档中提取元数据。

包含XML的文件名为meta.xml。

它的结构如下：

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <office:document-meta xmlns:office="urn:oasis:names:tc:opendocument:xmlns:office:1.0"  xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:meta="urn:oasis:names:tc:opendocument:xmlns:meta:1.0" office:version="1.2">
  3.     <office:meta>
  4.         <meta:creation-date>2016-10-18T15:05:19.137453293</meta:creation-date>
  5.         <dc:title>Document</dc:title>
  6.         <dc:date>2017-01-17T00:59:04.731054728</dc:date>
  7.         <meta:document-statistic meta:page-count="1" meta:word-count="0" meta:character-count="0"/>
  8.     </office:meta>
  9. </office:document-meta>

我正在使用encoding/xml包中的xml.Unmarshal()函数解析XML并将值放入结构体字段中。

这是我使用的结构体：

  1. type Query struct {
  2.     CreationDate string `xml:"meta:creation-date"`
  3.     PageCount int `xml:"meta:document-statistic>meta:page-count,attr"`
  4.     WordCount int `xml:"meta:document-statistic>meta:word-count,attr"`
  5.     CharCount int `xml:"meta:document-statistic>meta:character-count,attr"`
  6. }

根据现有文档的理解，我可以使用类型为xml:"tag-name"的字段标签来获取XML标签的值，使用xml:"name,attr"来获取属性值。

然而，由于XML文件具有命名空间标签（例如meta:creation-date），到目前为止，我尝试的所有方法都导致结构体字段为空。不过，我可能做错了什么。

这是在Go Playground中的完整程序：
https://play.golang.org/p/n7C50l1gsV

英文:

I'm trying to extract metadata from an .odt document.

The file containing XML is called meta.xml

It has this structure:

  1. &lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot;?&gt;
  2. &lt;office:document-meta xmlns:office=&quot;urn:oasis:names:tc:opendocument:xmlns:office:1.0&quot;  xmlns:dc=&quot;http://purl.org/dc/elements/1.1/&quot; xmlns:meta=&quot;urn:oasis:names:tc:opendocument:xmlns:meta:1.0&quot; office:version=&quot;1.2&quot;&gt;
  3.     &lt;office:meta&gt;
  4.         &lt;meta:creation-date&gt;2016-10-18T15:05:19.137453293&lt;/meta:creation-date&gt;
  5.         &lt;dc:title&gt;Document&lt;/dc:title&gt;
  6.         &lt;dc:date&gt;2017-01-17T00:59:04.731054728&lt;/dc:date&gt;
  7.         &lt;meta:document-statistic meta:page-count=&quot;1&quot; meta:word-count=&quot;0&quot; meta:character-count=&quot;0&quot;/&gt;
  8.     &lt;/office:meta&gt;
  9. &lt;/office:document-meta&gt;

I'm using xml.Unmarshal() from the encoding/xml package to parse the XML and place the values inside struct fields.

This is the struct I'm using:

  1. type Query struct {
  2. 	CreationDate string `xml:&quot;&quot;`
  3.     PageCount int `xml:&quot;&quot;`
  4. 	WordCount int `xml:&quot;&quot;`
  5. 	CharCount int `xml:&quot;&quot;`
  6. }

What I understood from the available documentation is that I can use field tags of type xml:&quot;tag-name&quot; to get the value of the XML tag, and xml:name,attr to get the attribute value.

However, since the XML file has namespaced tags (e.g. meta:creation-date) everything I've tried so far leaves the struct fields empty. Although, I might be doing something wrong.

This is the entire program inside Go playground:
https://play.golang.org/p/n7C50l1gsV

答案1

得分: 3

你会发现，如果你的结构体与XML相对应，事情会更顺利。以下是可以帮助你入门的代码：

  1. package main
  3. import (
  4. 	"encoding/xml"
  5. 	"fmt"
  6. )
  8. type Stats struct {
  9. 	XMLName   xml.Name
  10. 	PageCount int `xml:"page-count,attr"`
  11. }
  13. type Meta struct {
  14. 	XMLName xml.Name
  15. 	Date    string `xml:"creation-date"`
  16. 	Title   string `xml:"title"`
  17. 	Stats   Stats  `xml:"document-statistic"`
  18. }
  20. type DocumentMeta struct {
  21. 	XMLName xml.Name
  22. 	Meta    Meta `xml:"meta"`
  23. }
  25. var data = []byte(`<?xml version="1.0" encoding="UTF-8"?>
  26. <office:document-meta>
  27.     <office:meta>
  28.         <meta:creation-date>2016-10-18T15:05:19.137453293</meta:creation-date>
  29.         <dc:title>Document</dc:title>
  30.         <dc:date>2017-01-17T00:59:04.731054728</dc:date>
  31.         <meta:document-statistic meta:page-count="1" meta:word-count="0" meta:character-count="0"/>
  32.     </office:meta>
  33. </office:document-meta>`)
  35. func main() {
  36. 	var dm DocumentMeta
  37. 	xml.Unmarshal(data, &dm)
  38. 	fmt.Println(dm)
  39. }

希望对你有帮助！

英文:

You will find that things go more smoothly if your structs map fairly directly to the XML. This code should get you started:

  1. package main
  3. import (
  4. 	&quot;encoding/xml&quot;
  5. 	&quot;fmt&quot;
  6. )
  8. type Stats struct {
  9. 	XMLName   xml.Name
  10. 	PageCount int `xml:&quot;page-count,attr&quot;`
  11. }
  13. type Meta struct {
  14. 	XMLName xml.Name
  15. 	Date    string `xml:&quot;creation-date&quot;`
  16. 	Title   string `xml:&quot;title&quot;`
  17. 	Stats   Stats  `xml:&quot;document-statistic&quot;`
  18. }
  20. type DocumentMeta struct {
  21. 	XMLName xml.Name
  22. 	Meta    Meta `xml:&quot;meta&quot;`
  23. }
  25. var data = []byte(`&lt;?xml version=&quot;1.0&quot; encoding=&quot;UTF-8&quot;?&gt;
  26. &lt;office:document-meta&gt;
  27.     &lt;office:meta&gt;
  28.         &lt;meta:creation-date&gt;2016-10-18T15:05:19.137453293&lt;/meta:creation-date&gt;
  29.         &lt;dc:title&gt;Document&lt;/dc:title&gt;
  30.         &lt;dc:date&gt;2017-01-17T00:59:04.731054728&lt;/dc:date&gt;
  31.         &lt;meta:document-statistic meta:page-count=&quot;1&quot; meta:word-count=&quot;0&quot; meta:character-count=&quot;0&quot;/&gt;
  32.     &lt;/office:meta&gt;
  33. &lt;/office:document-meta&gt;`)
  35. func main() {
  36. 	var dm DocumentMeta
  37. 	xml.Unmarshal(data, &amp;dm)
  38. 	fmt.Println(dm)
  39. }

huangapple
  • 本文由 发表于 2017年2月14日 00:57:21
  • 转载请务必保留本文链接：https://go.coder-hub.com/42209427.html
  • go
  • unmarshalling
  • xml
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