我有一个简单的任务,需要访问一些属性的值。这是一个使用 Nokogiri::XML::Builder
创建简单 XML 文档的脚本。
require 'nokogiri'
builder = Nokogiri::XML::Builder.new(:encoding => 'UTF-8') do |xml|
xml.Placement(:messageId => "392847-039820-938777", :system => "MOD", :version => "2.0") {
xml.objects {
xml.object(:myattribute => "99", :anotherattrib => "333")
xml.nextobject_ '9387toot'
xml.Entertainment "Last Man Standing"
}
}
end
puts builder.to_xml
puts builder.root.attributes["messageId"]
结果如下:
<?xml version="1.0" encoding="UTF-8"?>
<Placement messageId="392847-039820-938777" version="2.0" system="MOD">
<objects>
<object anotherattrib="333" myattribute="99"/>
<nextobject>9387toot</nextobject>
<Entertainment>Last Man Standing</Entertainment>
</objects>
</Placement>
C:/Ruby/lib/ruby/gems/1.8/gems/nokogiri-1.4.2-x86-mingw32/lib/nokogiri/xml/document.rb:178:in `add_child': Document already has a root node (RuntimeError)
from C:/Ruby/lib/ruby/gems/1.8/gems/nokogiri-1.4.2-x86-mingw32/lib/nokogiri/xml/node.rb:455:in `parent='
from C:/Ruby/lib/ruby/gems/1.8/gems/nokogiri-1.4.2-x86-mingw32/lib/nokogiri/xml/builder.rb:358:in `insert'
from C:/Ruby/lib/ruby/gems/1.8/gems/nokogiri-1.4.2-x86-mingw32/lib/nokogiri/xml/builder.rb:350:in `method_missing'
from C:/Documents and Settings/etrojan/workspace/Lads/tryXPATH2.rb:15
生成的XML文件看起来很好。然而,我的尝试访问属性导致了一个错误:
生成的XML文件看起来很好。然而,我的尝试访问属性导致了一个错误:
Document already has a root node
我不理解为什么puts
会导致这个错误。
nokogiri_element.xpath("@id").text()
。 - stopankodoc.at_xpath
可以实现与elems[0]
相同的效果。doc.at_xpath("//*[@messageId]")['messageId']
会更简单。 - the Tin Man