From: Paul Lutus <nospam@...>
Date: 2006-11-17T08:20:09+09:00
Subject: Re: Ruby newbie & XML - What's the simplest way to get XML data into a hash?

darenbell@gmail.com wrote:

> Sorry for having such a specific question, but is there a simple way to
> take the XML document below and put it into some sort of organized hash
> value without first knowing anything about it?
> 
> This is an easy job using something like XML::Simple in Perl, but for
> the life of me, I can't figure out an easy way to do this in Ruby.

Try this:

---------------------------------

#!/usr/bin/ruby -w

data = File.read("data.xml")

root = {}
hash = root

stack = []

data.each do |line|
   line.strip!
   if line =~ %r{^<\w+>$}
      tag = line.sub(%r{<(.*?)>},"\\1")
      stack.push(hash)
      hash[tag] ||= {}
      hash = hash[tag]
   elsif line =~ %r{^</\w+>$}
      hash = stack.pop
   elsif line =~ %r{<(\w+)>.*?</\1>}
      key,value = line.scan(%r{<(\w+)>(.*?)<}).flatten
      hash[key] = value
   else
      puts "Error: undefined case: #{line}"
   end
end

def traverse_hash(hash,tab = 0)
   hash.keys.sort.each do |key|
      print "#{"   " * tab}"
      if(hash[key].class == Hash)
         puts  "#{key}"
         traverse_hash(hash[key],tab+1)
      else
         puts "#{key} = #{hash[key]}"
      end
   end
end

traverse_hash(root)

---------------------------------

Output:

environment
   authentication
      adminGroup
         dataType = NULL
         description = NULL
         value = NULL
      bindUserID
         dataType = NULL
         description = NULL
         value = NULL
      bindUserPassword
         dataType = NULL
         description = NULL
         value = NULL
      ldapServer
         dataType = NULL
         description = NULL
         value = NULL
   database
      databaseHost
         dataType = NULL
         description = NULL
         value = NULL
      databasePassword
         dataType = NULL
         description = NULL
         value = NULL
      databasePort
         dataType = NULL
         description = NULL
         value = NULL
      databaseSchema
         dataType = NULL
         description = NULL
         value = NULL
      databaseUser
         dataType = NULL
         description = NULL
         value = NULL


-- 
Paul Lutus
http://www.arachnoid.com