From: Stephen Bannasch <stephen.bannasch@...>
Date: 2006-03-24T11:28:54+09:00
Subject: Re: using builder to make jnlp xml elements with "-" in name?

[partially answering my own question ...]

The reason that builder can't create xml elements with "-" chars in 
the element is because strings with "-" chars are not legal Ruby 
symbols. Builder uses method_missing to create the xml element markup 
and so it seems Ruby's parser chokes when it tries to convert the 
string into a symbol.

I've got a workaround below but it is more general than I want (it 
replaces all "_" chars with "-"). I left some code commented out that 
I was trying too get working but didn't. It's a bit confusing to 
debug because the inheritance chain (XmlMarkup < XmlBase < 
BlankSlate) end up hiding all the normal methods -- I'm a bit 
surprised that my code works at all.

Anyway, I'm just learning Ruby and figuring out just what is going on 
here is fun.  If anybody has suggestions I'd appreciate it.

Thanks

#!/usr/bin/env ruby
# file: jnlpmarkup.rb

# extends Builder::XmlMarkup for creating XML markup for jnlp documents.
# Some jnlp elements have a "-" char in the element name. Builder doesn't
# accept this character. So this class postprocesses the result and replaces
# proxy jnlp element names such as "<application_desc>" with 
"<application-desc>"
#
# because I can't get what I intended to work right now this just
# replaces all "_" chars with '-' chars

require 'builder/xmlmarkup'

module Builder

   class JnlpMarkup < XmlMarkup

     @@jnlp_in =  %w{application_desc applet_desc component_desc 
installer_desc offline_allowed related_content all_permissions 
j2ee_application_client_permissions ext_download}
     @@jnlp_out = %w{application-desc applet-desc component-desc 
installer-desc offline-allowed related-content all-permissions 
j2ee-application-client-permissions ext-download}

     def method_missing(sym, *args, &block)
       super.gsub(/_/, '-')

# various things that didn't work below:
#      x = super
#      x = x.gsub(/application_desc/, 'application-desc')
#      x = x.gsub(/applet_desc/, 'applet_desc')
#      x = x.gsub(/#{@@jnlp_in[i]}/, @@jnlp_out[i])
#      @@jnlp_in.each_index do |i| x = x.gsub(/#{@@jnlp_in[i]}/, 
@@jnlp_out[i]) end
     end
   end
end



-- 
- Stephen Bannasch
   Concord Consortium, http://www.concord.org