如何在Powershell REPL控制台中打印xml元素及其属性的列表？

Question

参考资料：

https://www.red-gate.com/simple-talk/sysadmin/powershell/powershell-data-basics-xml/

以及：

https://stackoverflow.com/a/65264118/4531180

如何打印元素及其属性的列表？

PS /home/nicholas/powershell> 
PS /home/nicholas/powershell> $doc = new-object System.Xml.XmlDocument
PS /home/nicholas/powershell> $file = resolve-path('./bookstore.xml') 
PS /home/nicholas/powershell> $doc.load($file)                                           
PS /home/nicholas/powershell> 
PS /home/nicholas/powershell> $doc.bookstore.book[1].author.first-name
ParserError: 
Line |
   1 |  $doc.bookstore.book[1].author.first-name
     |                                     ~~~~~
     | Unexpected token '-name' in expression or statement.

PS /home/nicholas/powershell> 
PS /home/nicholas/powershell> $doc.bookstore.book[1].author           

first-name last-name
---------- ---------
Margaret   Atwood

PS /home/nicholas/powershell> 
PS /home/nicholas/powershell> $doc.bookstore

bk          book
--          ----
urn:samples {book, book, book, book}

PS /home/nicholas/powershell> 

Answer 1

来解决 for-display格式设置问题：

如果仔细查看示例输出从你自己的回答，您会发现尽管显示非常有用，但author属性的值是author，而不是显示(假定的) first-name和last-name子元素值。

问题是，PowerShell的默认输出格式表示具有的子元素

• 至少有一个属性
• 和/或至少有一个子元素本身()

由元素的名称命名，仅.

尤其是具有深嵌套元素的output.，这会导致无帮助的

Workarounds，可能结合在一起：

• .InnerXml访问这些元素的 .OuterXml 或.OuterXml属性，该属性包含元素本身带有/不带标记的完整XML文本。

- This will likely only be helpful with perhaps at most another level of nesting will be visually helpful, given that the XML text is a _single-line_ representation that is _not_ pretty-printed.

- You can **pipe** **`.OuterXml`** **/** **`InnerXml`** **values to a** _**pretty-printing**_ **function**, which **requires some extra work**, however, because no such functionality is directly exposed by PowerShell.

• 使用选择对象 (或仅用于显示目的) Format-* cmdlet (如Format-Table)和计算性质。

- While this allows you full control over what is displayed, it is more work.

见下面的例子。

# Sample XML document
$xmlDoc = [xml] @"
<?xml version="1.0"?>
<bookstore>
   <book id="bk101">
      <author>
        <first-name>Matthew</first-name>
        <last-name>Gambardella</last-name>
      </author>
      <title>XML Developer's Guide</title>
      <genre>Computer</genre>
      <price>44.95</price>
      <publish_date>2000-10-01</publish_date>
      <description>An in-depth look at creating applications with XML.</description>
   </book>
   <book id="bk102">
      <author>
        <first-name>Kim</first-name>
        <last-name>Rall</last-name>
      </author>
      <title>Midnight Rain</title>
      <genre>Fantasy</genre>
      <price>5.95</price>
      <publish_date>2000-12-16</publish_date>
      <description>A former architect battles corporate zombies, an evil sorceress, and her own childhood to become queen of the world.</description>
   </book>
</bookstore>
"@

要获得所有<book>元素的有用表示，包括<author>子元素的<first-name>和<last-name__>子元素，通过__>和计算的属性获取

$xmldoc.bookstore.book | Select-Object id, 
   @{ n='author'; e={ $_.author.'first-name' + ' ' + $_.author.'last-name'} }, 
   title, genre, price, publish_date, description

这将产生(注意author属性现在是如何列出名字和姓氏的)：

id           : bk101
author       : Matthew Gambardella
title        : XML Developer's Guide
genre        : Computer
price        : 44.95
publish_date : 2000-10-01
description  : An in-depth look at creating applications with XML.

id           : bk102
author       : Kim Rall
title        : Midnight Rain
genre        : Fantasy
price        : 5.95
publish_date : 2000-12-16
description  : A former architect battles corporate zombies, an evil sorceress, and her own childhood to become queen of the world.

要通过一个辅助<book>实例通过漂亮打印的XML获得所有System.Xml.Linq.XDocument元素的有用表示：

# Load the assembly that contains XDocument.
# Note: Required in Windows PowerShell only, and only once per session.
Add-Type -AssemblyName System.Xml.Linq

$xmldoc.bookstore.book | ForEach-Object {
  ([System.Xml.Linq.XDocument] $_.OuterXml).ToString()
}

这产生了(一种打印得很好的XML表示)：

<book id="bk101">
  <author>
    <first-name>Matthew</first-name>
    <last-name>Gambardella</last-name>
  </author>
  <title>XML Developer's Guide</title>
  <genre>Computer</genre>
  <price>44.95</price>
  <publish_date>2000-10-01</publish_date>
  <description>An in-depth look at creating applications with XML.</description>
</book>
<book id="bk102">
  <author>
    <first-name>Kim</first-name>
    <last-name>Rall</last-name>
  </author>
  <title>Midnight Rain</title>
  <genre>Fantasy</genre>
  <price>5.95</price>
  <publish_date>2000-12-16</publish_date>
  <description>A former architect battles corporate zombies, an evil sorceress, and her own childhood to become queen of the world.</description>
</book>

请注意，您可以将格式化代码包装在一个名为Format-Xml的简单(过滤器)函数中，您可以将该函数放在$PROFILE文件中(在Windows中，也可以将Add-Type -AssemblyName System.Xml.Linq放在该文件的上方)：

filter Format-Xml { ([System.Xml.Linq.XDocument] $_.OuterXml).ToString() }

现在，格式设置非常简单，如：

$xmldoc.bookstore.book | Format-Xml

Answer 2

只是不使用books

PS /home/nicholas/powershell> 
PS /home/nicholas/powershell> $doc.bookstore.book

genre           : novel
publicationdate : 1997
ISBN            : 1-861001-57-8
title           : Pride And Prejudice
author          : author
price           : 24.95

genre           : novel
publicationdate : 1992
ISBN            : 1-861002-30-1
title           : The Handmaid's Tale
author          : author
price           : 29.95

genre           : novel
publicationdate : 1991
ISBN            : 1-861001-57-6
title           : Emma
author          : author
price           : 19.95

genre           : novel
publicationdate : 1982
ISBN            : 1-861001-45-3
title           : Sense and Sensibility
author          : author
price           : 19.95


PS /home/nicholas/powershell> 

哇哦。