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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
259
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
A simpler approach based on the answer above:
regex = /subject|header/
headers = doc.css("table td:nth-child(1) div").find_all do
|h| h['class'] =~ regex
end
Thank you for posting this question.
32
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