From: Robert Klemme <shortcutter@...>
Date: 2013-03-27T17:25:00+09:00
Subject: Re: Nokogiri help parsing HTML

On Wed, Mar 27, 2013 at 12:05 AM, Jesús Gabriel y Galán
<jgabrielygalan@gmail.com> wrote:
> On Tue, Mar 26, 2013 at 11:40 PM, Paul Mena <lists@ruby-forum.com> wrote:

>> My goal is to strip out everything between the "address" and "pre" tags
>> and to output only:
>
> OK, so you want every tag that is a sibling of address and pre and is
> within those two. I have found this StackOverFlow answer:
>
> http://stackoverflow.com/a/6555376
>
> which applied to your problem:
>
> 1.9.2p290 :001 > require 'nokogiri'
>  => true
> 1.9.2p290 :002 > s = <<END
> 1.9.2p290 :003"> <!-- body="start" -->
> 1.9.2p290 :004"> <div class="mail">
> [...snip...]
> 1.9.2p290 :031 > doc = Nokogiri::HTML(s)
> 1.9.2p290 :039 >
> doc.xpath("//address/following-sibling::node()[count(.|
> //pre/preceding-sibling::node())=count(//pre/preceding-sibling::node())]")
>  => [#<Nokogiri::XML::Text:0xdb0114 "\n">,
> #<Nokogiri::XML::Element:0xdaff84 name="p"
> children=[#<Nokogiri::XML::Text:0xdafc28 "\nLine 1\n">,
> #<Nokogiri::XML::Element:0xdafa5c name="br">,
> #<Nokogiri::XML::Text:0xdaf728 "\nLine 2\n">,
> #<Nokogiri::XML::Element:0xdaf5ac name="br">,
> #<Nokogiri::XML::Text:0xdaf228 "\nLine 3\n">,
> #<Nokogiri::XML::Element:0xdaf0ac name="br">]>,
> #<Nokogiri::XML::Element:0xdaea80 name="p">]
>
> will return a node set that contains the required nodes.

Your version also outputs <p> tags, doesn't it?  A modified version of yours

irb(main):036:0>
dom.xpath('//address/following-sibling::*//text()').each {|n| p n}
#<Nokogiri::XML::Text:0x..fc01de63e "\nLine 1\n">
#<Nokogiri::XML::Text:0x..fc01de4d6 "\nLine 2\n">
#<Nokogiri::XML::Text:0x..fc01de36e "\nLine 3\n">
#<Nokogiri::XML::Text:0x..fc01de206 "\n">
#<Nokogiri::XML::Text:0x..fc01ddf04 "\n">
=> 0

irb(main):037:0>
dom.xpath('//address/following-sibling::p//text()').each {|n| p n}
#<Nokogiri::XML::Text:0x..fc01de63e "\nLine 1\n">
#<Nokogiri::XML::Text:0x..fc01de4d6 "\nLine 2\n">
#<Nokogiri::XML::Text:0x..fc01de36e "\nLine 3\n">
#<Nokogiri::XML::Text:0x..fc01de206 "\n">
=> 0

Here's another approach: find everything under <div class="mail"> but
not under <address>:

irb(main):032:0>
dom.xpath('//div[@class="mail"]//text()[not(ancestor::address)]').each
{|n| p n}
#<Nokogiri::XML::Text:0x..fc01c07c4 "\n">
#<Nokogiri::XML::Text:0x..fc01de7b0 "\n">
#<Nokogiri::XML::Text:0x..fc01de63e "\nLine 1\n">
#<Nokogiri::XML::Text:0x..fc01de4d6 "\nLine 2\n">
#<Nokogiri::XML::Text:0x..fc01de36e "\nLine 3\n">
#<Nokogiri::XML::Text:0x..fc01de206 "\n">
#<Nokogiri::XML::Text:0x..fc01ddf04 "\n">
=> 0

TIMTOWTDI  :-)

Kind regards

robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/