From: TAKAHASHI Masayoshi <maki@...>
Date: 2001-02-26T21:05:59+09:00
Subject: [ruby-talk:11582] Re: A design/implementation question

Hi,

I tried ri. My impression: Cool!

Dave Thomas <Dave@PragmaticProgrammer.com> wrote:
> To do that with the current scheme would require that every client
> have the Ruby xmlparser module installed, which in turn requires Jim
> Clark's expat library. This seems onerous!
> 
> So, I initially started hacking together yet another flat file
> representation of the data. I'd ship it with ri, and when you type
> 'ruby install.rb', the installer would read it and generate the
> marshaled classes. Then that little alarm bell started ringing that
> said "there has to be a better way". Unfortunately, the battery ran
> down before it got around to telling me what that better way is.
> 
> So, any ideas?

We have already used a very useful flat file representation
of the data: Ruby script :-)

If your problem is installing xmlparser.so, not using xmltree.rb,
how about a plan as follows?
  1. convert XML file into Ruby script that builds DOM tree.
  2. distribute the script, xmltree.rb and some scripts using
     DOM to generate the marshaled data.

I attach simple script coverting XML file to Ruby script.

# I refered to MoonWolf's rd2xml.rb. Thanks! > MoonWolf

TAKAHASHI Masayoshi (maki@inac.co.jp)



#!/usr/bin/env ruby -Ku
require 'uconv'
require 'xmlparser'
require 'xmltree'
require 'xmltreebuilder'
require 'xmltreevisitor'

class XML2DOMVisitor<XML::SimpleTree::Visitor

  def initialize
  end
  
  def visit_Document(grove, *rest)
    super
  end
  
  def visit_Element(element, *rest)
    ret = "Element.new("
    ret += "'"+element.nodeName+"',"
    ret += "{"
    attrs = []
    nn = element.attributes
    nn.each{|node|
      attrs << '"' + node.name + '" => "' + node.value + '"'
    }
    ret += attrs.join(",")
    ret += "},["
    ret += element.children_accept(self, *rest).join(',').to_s
    ret += "])"
    ret
  end
  
  def visit_Text(text, *rest)
    ret = "Text.new('"
    ret += text.data.gsub("'","\\\\'")
    ret += "')"
    ret
  end
  
  def visit_CDATASection(text, *rest)
    # ignore.
  end
  
  def visit_Comment(comment, *rest)
    # ignore.
  end
  
  def visit_ProcessingInstruction(pi, *rest)
    # ignore.
  end
end

doc = XML::SimpleTreeBuilder.new.parse($<.read)

print "#!/usr/bin/env ruby -Ku\n"
print "require 'xmltree'\n"
print "include XML\n"
print "include XML::DOM\n"
print "$domtree = Document.new("
print  doc.accept(XML2DOMVisitor.new, []).to_s
print ")\n"