Ruby使用rexml解析xml

在开发中常用到xml解析，在ruby中我们可以使用rexml来解析xml,rexml具有如下特点:

##下面我们来看看如何使用它,假设我们有如下xml文件：

<collection shelf="New Arrivals">
	<movie title="Enemy Behind">
		<type>War, Thriller</type>
		<format>DVD</format>
		<year>2003</year>
		<rating>PG</rating>
		<stars>10</stars>
		<description>Talk about a US-Japan war</description>
	</movie>
	<movie title="Transformers">
		<type>Anime, Science Fiction</type>
		<format>DVD</format>
		<year>1989</year>
		<rating>R</rating>
		<stars>8</stars>
		<description>A schientific fiction</description>
	</movie>
	<movie title="Trigun">
		<type>Anime, Action</type>
		<format>DVD</format>
		<episodes>4</episodes>
		<rating>PG</rating>
		<stars>10</stars>
		<description>Vash the Stampede!</description>
	</movie>
	<movie title="Ishtar">
		<type>Comedy</type>
		<format>VHS</format>
		<rating>PG</rating>
		<stars>2</stars>
		<description>Viewable boredom</description>
	</movie>
</collection>

##解析DOM：

require 'rexml/document'
include REXML
xmlfile = File.new("movies.xml")
xmldoc = Document.new(xmlfile)
root = xmldoc.root
puts "Root element : " + root.attributes["shelf"]
xmldoc.elements.each("collection/movie"){
	|e| puts "Movie Title : " + e.attributes["title"]
}
xmldoc.elements.each("collection/movie/type") {
	|e| puts "Movie Type : " + e.text
}
xmldoc.elements.each("collection/movie/description") {
	|e| puts "Movie Description : " + e.text
}

##使用XPATH：

require 'rexml/document'
include REXML
xmlfile = File.new("movies.xml")
xmldoc = Document.new(xmlfile)
movie = XPath.first(xmldoc, "//movie")
p movie
XPath.each(xmldoc, "//type") { |e| puts e.text }
names = XPath.match(xmldoc, "//format").map {|x| x.text }
p names

以备不时之需!

163 Words 12 December 2011 Suzhou, China