如何使用Nokogiri解析XML文件？

Question

如何使用Nokogiri解析XML文件？

我和Nokogiri有一些问题.

我试图解析这个XML文件:

<Collection version="2.0" id="74j5hc4je3b9">
  <Name>A Funfair in Bangkok</Name>
  <PermaLink>Funfair in Bangkok</PermaLink>
  <PermaLinkIsName>True</PermaLinkIsName>
  <Description>A small funfair near On Nut in Bangkok.</Description>
  <Date>2009-08-03T00:00:00</Date>
  <IsHidden>False</IsHidden>
  <Items>
    <Item filename="AGC_1998.jpg">
      <Title>Funfair in Bangkok</Title>
      <Caption>A small funfair near On Nut in Bangkok.</Caption>
      <Authors>Anthony Bouch</Authors>
      <Copyright>Copyright © Anthony Bouch</Copyright>
      <CreatedDate>2009-08-07T19:22:08</CreatedDate>
      <Keywords>
        <Keyword>Funfair</Keyword>
        <Keyword>Bangkok</Keyword>
        <Keyword>Thailand</Keyword>
      </Keywords>
      <ThumbnailSize width="133" height="200" />
      <PreviewSize width="532" height="800" />
      <OriginalSize width="2279" height="3425" />
    </Item>
    <Item filename="AGC_1164.jpg" iscover="True">
      <Title>Bumper Cars at a Funfair in Bangkok</Title>
      <Caption>Bumper cars at a small funfair near On Nut in Bangkok.</Caption>
      <Authors>Anthony Bouch</Authors>
      <Copyright>Copyright © Anthony Bouch</Copyright>
      <CreatedDate>2009-08-03T22:08:24</CreatedDate>
      <Keywords>
        <Keyword>Bumper Cars</Keyword>
        <Keyword>Funfair</Keyword>
        <Keyword>Bangkok</Keyword>
        <Keyword>Thailand</Keyword>
      </Keywords>
      <ThumbnailSize width="200" height="133" />
      <PreviewSize width="800" height="532" />
      <OriginalSize width="3725" height="2479" />
    </Item>
  </Items>
</Collection>

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我希望所有这些信息都显示在屏幕上,就是这样.应该简单吧？我这样做:

require 'nokogiri'

doc = Nokogiri::XML(File.open("sample.xml"))
@block = doc.css("items item").map {|node| node.children.text}
puts @block

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每个Items都是一个节点,在那之下有子节点Item？

我创建了一个这样的地图,它返回一个哈希值,代码{}遍历每个节点并将子文本放入@block.然后我可以将所有子节点的文本显示在屏幕上.

我不知道我有多远或多近,因为我读了这么多文章,并且我仍然对基础知识有点困惑,特别是因为通常使用新语言,我从文件中读取并输出到屏幕上以获得基本知识程序.

Answer 1

Aru*_*hit 28

在这里,我将尝试向您解释您遇到的所有问题/困惑:

require 'nokogiri'

doc = Nokogiri::XML.parse <<-XML
<Collection version="2.0" id="74j5hc4je3b9">
  <Name>A Funfair in Bangkok</Name>
  <PermaLink>Funfair in Bangkok</PermaLink>
  <PermaLinkIsName>True</PermaLinkIsName>
  <Description>A small funfair near On Nut in Bangkok.</Description>
  <Date>2009-08-03T00:00:00</Date>
  <IsHidden>False</IsHidden>
  <Items>
    <Item filename="AGC_1998.jpg">
      <Title>Funfair in Bangkok</Title>
      <Caption>A small funfair near On Nut in Bangkok.</Caption>
      <Authors>Anthony Bouch</Authors>
      <Copyright>Copyright © Anthony Bouch</Copyright>
      <CreatedDate>2009-08-07T19:22:08</CreatedDate>
      <Keywords>
        <Keyword>Funfair</Keyword>
        <Keyword>Bangkok</Keyword>
        <Keyword>Thailand</Keyword>
      </Keywords>
      <ThumbnailSize width="133" height="200" />
      <PreviewSize width="532" height="800" />
      <OriginalSize width="2279" height="3425" />
    </Item>
    <Item filename="AGC_1164.jpg" iscover="True">
      <Title>Bumper Cars at a Funfair in Bangkok</Title>
      <Caption>Bumper cars at a small funfair near On Nut in Bangkok.</Caption>
      <Authors>Anthony Bouch</Authors>
      <Copyright>Copyright © Anthony Bouch</Copyright>
      <CreatedDate>2009-08-03T22:08:24</CreatedDate>
      <Keywords>
        <Keyword>Bumper Cars</Keyword>
        <Keyword>Funfair</Keyword>
        <Keyword>Bangkok</Keyword>
        <Keyword>Thailand</Keyword>
      </Keywords>
      <ThumbnailSize width="200" height="133" />
      <PreviewSize width="800" height="532" />
      <OriginalSize width="3725" height="2479" />
    </Item>
  </Items>
</Collection>
XML

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因此,根据我对Nokogiri的理解,每个'Items'都是一个节点,在那之下有'Item'的子节点？

不,每个项目都是Nokogiri::XML::NodeSet.在那之下,有2个子节点的Items,它们是Nokogiri::XML::Element类对象.你也可以这么说Nokogiri::XML::Node

doc.class # => Nokogiri::XML::Document
@block = doc.xpath("//Items/Item")
@block.class # => Nokogiri::XML::NodeSet
@block.count # => 2
@block.map { |node| node.name }
# => ["Item", "Item"]
@block.map { |node| node.class }
# => [Nokogiri::XML::Element, Nokogiri::XML::Element]
@block.map { |node| node.children.count }
# => [19, 19]
@block.map { |node| node.class.superclass }
# => [Nokogiri::XML::Node, Nokogiri::XML::Node]

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我们创建了一个这样的地图,它返回一个我认为的哈希,{}中的代码遍历每个节点并将子文本放入@block.然后我可以将所有这个子节点的文本显示在屏幕上.

我不明白这一点.虽然我试图下面解释显示什么是节点,什么是节点组中引入nokogiri.记住Nodeset是节点的集合.

@chld_class = @block.map do |node|
  node.children.class
end
@chld_class
# => [Nokogiri::XML::NodeSet, Nokogiri::XML::NodeSet]
@chld_name = @block.map do |node|
  node.children.map { |n| [n.name,n.class] }
end
@chld_name
# => [[["text", Nokogiri::XML::Text],
#      ["Title", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text],
#      ["Caption", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text],
#      ["Authors", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text],
#      ["Copyright", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text],
#      ["CreatedDate", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text],
#      ["Keywords", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text],
#      ["ThumbnailSize", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text],
#      ["PreviewSize", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text],
#      ["OriginalSize", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text]],
#     [["text", Nokogiri::XML::Text],
#      ["Title", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text],
#      ["Caption", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text],
#      ["Authors", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text],
#      ["Copyright", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text],
#      ["CreatedDate", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text],
#      ["Keywords", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text],
#      ["ThumbnailSize", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text],
#      ["PreviewSize", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text],
#      ["OriginalSize", Nokogiri::XML::Element],
#      ["text", Nokogiri::XML::Text]]]

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@chld_name = @block.map do |node|
  node.children.map{|n| [n.name,n.text.strip] if n.elem? }.compact
end.compact
@chld_name
# => [[["Title", "Funfair in Bangkok"],
#      ["Caption", "A small funfair near On Nut in Bangkok."],
#      ["Authors", "Anthony Bouch"],
#      ["Copyright", "Copyright © Anthony Bouch"],
#      ["CreatedDate", "2009-08-07T19:22:08"],
#      ["Keywords", "Funfair\n        Bangkok\n        Thailand"],
#      ["ThumbnailSize", ""],
#      ["PreviewSize", ""],
#      ["OriginalSize", ""]],
#     [["Title", "Bumper Cars at a Funfair in Bangkok"],
#      ["Caption", "Bumper cars at a small funfair near On Nut in Bangkok."],
#      ["Authors", "Anthony Bouch"],
#      ["Copyright", "Copyright © Anthony Bouch"],
#      ["CreatedDate", "2009-08-03T22:08:24"],
#      ["Keywords",
#       "Bumper Cars\n        Funfair\n        Bangkok\n        Thailand"],
#      ["ThumbnailSize", ""],
#      ["PreviewSize", ""],
#      ["OriginalSize", ""]]]

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Answer 2

ord*_*rde 5

示例XML中的节点大写，因此您的代码应反映出来。例如：

require 'nokogiri'

doc = Nokogiri::XML(File.open("sample.xml"))
@block = doc.css("Items Item").map { |node| node.children.text }
puts @block

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