How to check if a particular node is present in XML in Ruby -

i want check if node present under specific node, can present in level. (it can deeper).

for xml:

<main>   <sub>     <inner>       <first></first>       <second></second>     </inner>   </sub> </main> 

how check see whether sub node has inner node first or not, using nokogiri without using xpath '/sub/inner' directly?

your xpath isn't correct unless know sub node @ top level. think of xpath selectors paths in os. /sub @ root of drive.

i'd recommend using css selectors clarity:

require 'nokogiri'  doc = nokogiri::html(<<eot) <main>   <sub>     <inner>       <first>first_text</first>       <second></second>     </inner>   </sub> </main> eot  doc.at('sub first').text # => "first_text" 

'sub first' means first has exist somewhere under 'sub'.

this might help:

require 'nokogiri'  doc = nokogiri::html(<<eot) <main>   <sub>     <inner>       <first>first_text</first>       <second></second>     </inner>   </sub> </main> eot  doc.at('/sub/first') # => nil doc.at('sub first') # => #<nokogiri::xml::element:0x3fd580c9e54c name="first" children=[#<nokogiri::xml::text:0x3fd580c9e2f4 "first_text">]> doc.at('//sub/*/first') # => #<nokogiri::xml::element:0x3fd580c9e54c name="first" children=[#<nokogiri::xml::text:0x3fd580c9e2f4 "first_text">]> doc.at('//sub//first') # => #<nokogiri::xml::element:0x3fd580c9e54c name="first" children=[#<nokogiri::xml::text:0x3fd580c9e2f4 "first_text">]>  doc.at('sub first').text # => "first_text" doc.at('//sub/*/first').text # => "first_text" doc.at('//sub//first').text # => "first_text"