Build XML from template w/ Nokogiri

builder.rb

template = File.read('/path/to/template')

builder = Nokogiri::XML::Builder.new do |xml|
    eval File.read(template)
end 

builder.to_xml

categories.builder

xml.root {
  xml.categories {
    @categories.each do |cat|
      xml.category {
        xml.title cat.title
        xml.videos {
          cat.videos.each do |vid|
            xml.video {
              xml.title vid.title
              xml.description vid.description
              xml.live vid.live
              xml.format vid.format
              xml.medias {
                xml.media {
                  xml.url vid.url
                  xml.bitrate vid.bitrate
                  xml.quality vid.quality
                }
              }
              xml.sd_image ''
              xml.hd_image ''
            }
          end  
        }
      }
    end  
  }
}