Nokogiri：如何找到<select>的选中选项？

Question

我需要获取所选 HTML 选项的值：

<select  name="DisplayCurrency" id="DisplayCurrency" >
<option  value="GBP" >Pounds Sterling</option>
<option  value="EUR"  selected="selected" >Euros</option>
<option  value="CHF" >Swiss Francs</option>
<option  value="DKK" >Danish Krona</option>
<option  value="CSK" >Czech Krowns</option>
<option  value="HUF" >Hungarian Forints</option>
<option  value="PLN" >Polish Zloty</option>
</option>
</select>

我用 Nokogiri 试过这个，但它不起作用：

page.search('//select[@id="DisplayCurrency"]/option[@selected=selected]').attr('value')

Answer 1

这对我有用，即使标记无效：

require 'nokogiri'
doc = Nokogiri::XML <<ENDXML
  <select name="DisplayCurrency" id="DisplayCurrency" >
  <option value="GBP" >Pounds Sterling</option>
  <option value="EUR" selected="selected" >Euros</option>
  <option value="CHF" >Swiss Francs</option>
  <option value="DKK" >Danish Krona</option>
  <option value="CSK" >Czech Krowns</option>
  <option value="HUF" >Hungarian Forints</option>
  <option value="PLN" >Polish Zloty</option>
  </option>
  </select>
ENDXML

puts doc.css('#DisplayCurrency option[@selected="selected"]').attr('value')
#=> EUR

puts doc.at_xpath('//select[@id="DisplayCurrency"]/option[@selected="selected"]').attr('value')
#=> EUR

puts doc.at_xpath('//*[@id="DisplayCurrency"]/option[@selected="selected"]/@value').value
#=> EUR

p RUBY_VERSION, Nokogiri::VERSION
#=> "1.9.2"
#=> "1.4.4"