Question

I have a file with the following structure

<admin>
 <sampleName>Willow oak leaf</sampleName>
 <sampleDescription comment="Total genes">
  <cvParam cvLabel="Bob" accession="123" name="Oak" />      
 </sampleDescription> 
</admin>

I’m trying to get out the text “Total genes” after the sampleDescription comment, and I have used the following code:

sampleDescription = doc.xpath( "/admin/Description/@comment" )
sampleDescription = doc.xpath( "/admin/Description" ).text

But neither work. What am I missing?

Answer 1

doc.xpath returns a NodeSet which acts a bit like an array. So you need to grab the first element

doc.xpath("//admin/sampleDescription").first['comment']

You could also use at_xpath which is equivalent to xpath(foo).first

doc.at_xpath("//admin/sampleDescription")['comment']

Another thing to note is that attributes on nodes are accessed like hash elements–with [<key>]