Nokogiri:搜索<div>使用 XPath [英] Nokogiri: Searching for <div> using XPath
问题描述
我使用 Nokogiri (Rubygem) css 搜索来寻找特定的 <div> 在我的 html 中.看起来 Nokogiri 的 css 搜索不喜欢正则表达式.我想切换到 Nokogiri 的 xpath 搜索，因为它似乎支持搜索字符串中的正则表达式.>
如何在 xpath 搜索中实现下面提到的(伪)css 搜索?
需要'rubygems'需要'nokogiri'value = Nokogiri::HTML.parse(<<-HTML_END)"<身体><p id='para-1'>A</p><p id='para-22'>B</p><h1>Bla</h1><p id='para-3'>C</p><p id='para-4'>D</p><div class="foo" id="eq-1_bl-1"><p id='para-5'>3</p></html>"HTML_END# my_block 已给出my_bl = "1"# my_eq 对应这个正则表达式my_eq = "\/[0-9]+\/"# FIXME 以下行应更改为 xpath 搜索.if my_div = value.css("div#eq-#{my_eq}_bl-#{my_bl}.foo").first# 用 <p> 做一些事情在div里面结尾
Mike Dalessio(一半的Nokogiri 核心开发人员)在 #nokogiri (irc.freenode.net) 上给了我一个答案.看起来 Nokogiri CSS 和 XPath 搜索都不支持正则表达式匹配.这是他关于如何使用 Nokogiri 搜索正则表达式的解决方案:
需要'rubygems'需要'nokogiri'value = Nokogiri::HTML.parse(<<-HTML_END)"<身体><p id='para-1'>A</p><p id='para-22'>B</p><h1>Bla</h1><p id='para-3'>C</p><p id='para-4'>D</p><div class="foo" id="eq-1_bl-1"><p id='para-5'>3</p><div class="bar" id="eq-1_bl-1"><p id='para-5'>3</p>
</html>"HTML_END# my_block 已给出my_bl = "1"# my_eq 对应这个正则表达式my_eq = "[0-9]+"# 在节点 id 中搜索的完整正则表达式full_regex = %r(eq-#{my_eq}_bl-#{my_bl})filter_by_id = Class.new 做attr_accessor :匹配定义初始化(正则表达式)@regex = 正则表达式@matches = []结尾def过滤器(节点集)@matches += node_set.find_all { |x|x['id'] =~ @regex }结尾end.new(full_regex)value.css("div.foo:filter()", filter_by_id)filter_by_id.matches.each 做 |node|放置节点结尾
I use Nokogiri (Rubygem) css search to look for certain <div> inside my html. It looks like Nokogiri's css search doesn't like regex. I would like to switch to Nokogiri's xpath search as this seems to support regex in search strings.
How do I implement the (pseudo) css search mentioned below in an xpath search?
require 'rubygems'
require 'nokogiri'
value = Nokogiri::HTML.parse(<<-HTML_END)
"<html>
<body>
<p id='para-1'>A</p>
<p id='para-22'>B</p>
<h1>Bla</h1>
<p id='para-3'>C</p>
<p id='para-4'>D</p>
<div class="foo" id="eq-1_bl-1">
<p id='para-5'>3</p>
</div>
</body>
</html>"
HTML_END
# my_block is given
my_bl = "1"
# my_eq corresponds to this regex
my_eq = "\/[0-9]+\/"
# FIXME The following line should be changed to an xpath search.
if my_div = value.css("div#eq-#{my_eq}_bl-#{my_bl}.foo").first
# doing some stuff with the <p> inside the div
end
Mike Dalessio (one half of the Nokogiri core developers) gave me an answer on #nokogiri (irc.freenode.net). Looks like neither Nokogiri CSS nor XPath search do support regex matching. This is his solution on how to search for regular expressions with Nokogiri:
require 'rubygems'
require 'nokogiri'
value = Nokogiri::HTML.parse(<<-HTML_END)
"<html>
<body>
<p id='para-1'>A</p>
<p id='para-22'>B</p>
<h1>Bla</h1>
<p id='para-3'>C</p>
<p id='para-4'>D</p>
<div class="foo" id="eq-1_bl-1">
<p id='para-5'>3</p>
</div>
<div class="bar" id="eq-1_bl-1">
<p id='para-5'>3</p>
</div>
</body>
</html>"
HTML_END
# my_block is given
my_bl = "1"
# my_eq corresponds to this regex
my_eq = "[0-9]+"
# full regex to search for in node ids
full_regex = %r(eq-#{my_eq}_bl-#{my_bl})
filter_by_id = Class.new do
attr_accessor :matches
def initialize(regex)
@regex = regex
@matches = []
end
def filter(node_set)
@matches += node_set.find_all { |x| x['id'] =~ @regex }
end
end.new(full_regex)
value.css("div.foo:filter()", filter_by_id)
filter_by_id.matches.each do |node|
puts node
end
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