re = /<(.+?)>[^<]+<\/\1>/m
str = '<EightSquaredSchema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xdt="http://www.w3.org/2005/xpath-datatypes" xmlns:fn="http://www.w3.org/2005/xpath-functions">
<A>
<nested-A>valid text</nested-A>
Remove text not inside valid xml braces
<nested-B>more valid text here</nested-B>
</A>
</EightSquaredSchema>
'
# Print the match result
str.scan(re) do |match|
puts match.to_s
end
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Ruby, please visit: http://ruby-doc.org/core-2.2.0/Regexp.html