问题
Given:
require 'rubygems'
require 'nokogiri'
value = Nokogiri::HTML.parse(<<-HTML_END)
"<html>
<body>
<p id='para-1'>A</p>
<div class='block' id='X1'>
<h1>Foo</h1>
<p id='para-2'>B</p>
</div>
<p id='para-3'>C</p>
<h2>Bar</h2>
<p id='para-4'>D</p>
<p id='para-5'>E</p>
<div class='block' id='X2'>
<p id='para-6'>F</p>
</div>
</body>
</html>"
HTML_END
I want to do something like what I can do in Hpricot:
divs = value.search('//div[@id^="para-"]')
- How do I do a pattern search for elements in XPath style?
- Where would I find the documentation to help me? I didn't see this in the rdocs.
回答1:
Use the xpath function starts-with:
value.xpath('//p[starts-with(@id, "para-")]').each { |x| puts x['id'] }
回答2:
divs = value.css('div[id^="para-"]')
回答3:
And some docs you're seeking:
- Nokogiri: http://nokogiri.org/
- XPath: http://www.w3.org/TR/xpath20/
- CSS3 Selectors: http://www.w3.org/TR/selectors/
回答4:
Nokogiri::XML::Node.send(:define_method, 'xpath_regex') { |*args|
xpath = args[0]
rgxp = /\/([a-z]+)\[@([a-z\-]+)~=\/(.*?)\/\]/
xpath.gsub!(rgxp) { |s| m = s.match(rgxp); "/#{m[1]}[regex(.,'#{m[2]}','#{m[3]}')]" }
self.xpath(xpath, Class.new {
def regex node_set, attr, regex
node_set.find_all { |node| node[attr] =~ /#{regex}/ }
end
}.new)
}
Usage:
divs = Nokogiri::HTML(page.root.to_html).
xpath_regex("//div[@class~=/axtarget$/]//div[@class~=/^carbo/]")
来源：https://stackoverflow.com/questions/1556028/how-do-i-do-a-regex-search-in-nokogiri-for-text-that-matches-a-certain-beginning