Parsing an XML document with Nokogiri when the node names are/contain integers-CodePudding

When I run:

#!/usr/bin/env ruby
require 'nokogiri'

xml = <<-EOXML
<pajamas>
  <bananas>
    <foo>bar</foo>
    <bar>bar</bar>
    <1>bar</1>
  </bananas>
</pajamas>
EOXML

doc = Nokogiri::XML(xml)
puts doc.at('/pajamas/bananas/foo')
puts doc.at('/pajamas/bananas/bar')
puts doc.at('/pajamas/bananas/1')

I get an ERROR: Invalid expression: /pajamas/bananas/1 (Nokogiri::XML::XPath::SyntaxError)

Is this a case of Nokogiri not liking ints as node names and/or is there a work around?

Looking at the documentation, I did not see a workaround to this. Removing the last line eliminates the error and prints the first two nodes as expected.

CodePudding user response：

An XML element with a name that starts with a number is invalid XML.

XML elements must follow these naming rules:

Names can contain letters, numbers, and other characters
Names cannot start with a number or punctuation character
Names cannot start with the letters xml (or XML, or Xml, etc)
Names cannot contain spaces Any name can be used, no words are reserved.

You're trying to parse invalid XML with a XML parser, it's just not going to work. If you're really getting <1> as a tag and can't control that somehow, I'd suggest replacing the tags using a regex before getting to nokogiri.