Pretty Print XML using Ruby

jrobertson (James Robertson) — Mon, 07 Jan 2008 01:41:26 GMT

This code makes the XML output look pretty. I tried using the documentation from the REXML website to apply the method example doc.write($stdout,0), but I gave up, and instead wrote my own XML pretty-print method.



require 'rexml/document'

include REXML



  def pretty_print(parent_node, itab)

    buffer = ''



    parent_node.elements.each do |node|



      buffer += ' ' * itab + "<#{node.name}#{get_att_list(node)}"

  

      if node.to_a.length > 0

        buffer += ">"

        if node.text.nil?

          buffer += "\n"

          buffer += pretty_print(node,itab+2) 

          buffer += ' ' * itab + "\n"

        else

          node_text = node.text.strip

          if node_text != ''

            buffer += node_text 

            buffer += "\n"        

          else

            buffer += "\n" + pretty_print(node,itab+2) 

            buffer += ' ' * itab + "\n"        

          end

        end

      else

        buffer += "/>\n"

      end

      

    end

    buffer

  end



  def get_att_list(node)

    att_list = ''

    node.attributes.each { |attribute, val| att_list += " #{attribute}='#{val}'" }

    att_list

  end

  

  def pretty_xml(doc)

    buffer = ''

    xml_declaration = doc.to_s.match('<\?.*\?>').to_s

    buffer += "#{xml_declaration}\n" if not xml_declaration.nil?

    xml_doctype = doc.to_s.match('<\!.*\">').to_s

    buffer += "#{xml_doctype}\n" if not xml_doctype.nil?

    buffer += "<#{doc.root.name}#{get_att_list(doc.root)}"

    if doc.root.to_a.length > 0

      buffer +=">\n#{pretty_print(doc.root,2)}"

    else

      buffer += "/>\n"

    end

  end



xml_data = "Ruby"

doc = Document.new(xml_data)

pretty_xml(doc)

output
Ruby

*Update 7-Jan-08 1:51AM *
Although I haven't tried running the following XSL code, this might actually have been a better solution to my problem. source: http://www.printk.net/~bds/indent.html

*Pretty Print XML using XSLT*

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