From: "Andrew S. Townley" <ast@...>
Date: 2009-03-27T20:16:16+09:00
Subject: Re: [ANN] tagz-5.0.0

On Fri, 2009-03-27 at 02:28 +0900, ara.t.howard wrote:
> On Mar 26, 2009, at 5:43 AM, Andrew S. Townley wrote:
> if that's the case i might roll something like that into tagz.

That would be fantastic.

> i'll post any other ideas i have here - really appreciate the feedback!

I'm looking at trying to figure out how to do the emit stuff, and I
think that the Namespace class should certainly be part of Tagz. 

New would do something similar to your example, but with also adding the
Namespace URI, e.g. (example from
http://www.w3schools.com/Xforms/xforms_namespace.asp)

include Tagz.globally

xhtml = Tagz::Namespace.new(:xhtml => "http://www.w3.org/1999/xhtml")
xf = Tagz::Namespace.new(:xf => "http://www.w3.org/2002/xforms")

etc.

I tried to do this based on the example you provided, but I'm getting an
error I don't understand.  I'm sure it's due to scoping issues, but I've
no idea how to fix it.

I also discovered that output of empty elements doesn't behave as I'd
expect.  If you do

empty_element_

you get "<empty_element>"

rather than "<empty_element/>"

I think this can be fixed easily with a check to see if the value of
tagz is empty on line 62.

Any ideas as to what's going on?

excalibur$ cat /tmp/a.rb
require 'rubygems'
require 'tagz'

class Namespace
  def initialize hash, &block
     @prefix, @uri = hash.inject([]) { |a, (k, v)| a << k << v }
     @context = block
     @self = eval 'self', block
  end

  instance_methods.each{|m| undef_method if m[%r/__/]}

  def emit_ns
    { "xmlns:#{ @prefix }".to_sym => "#{@uri}" }
  end

  def method_missing m, *a, &b
    if m.to_s[%r/^_|_$/]
      @self.send("#{ @prefix }:#{ m }", *a, &b)
    else
      "#{ @prefix }:#{ m }"
    end
  end
end

include Tagz.globally

xhtml = Namespace.new(:xhtml => "http://www.w3.org/1999/xhtml")
xf = Namespace.new(:xf => "http://www.w3.org/2002/xforms")

puts xhtml.emit_ns.inspect
puts xf.emit_ns.inspect

# BUG!!
puts empty_element_

doc = 
  xhtml.html_(xhmtl.emit_ns, xf.emit_ns) {
    xhtml.head_{
       xhtml.title_ "Important Document"
       xf.model_{
         xf.instance_{
           person_{
             fname_
             lname_
           }
         }
       }
       xf.submission(:id => "form1", :method => "get", :action => "doit.jsp")
    }
    xhtml.body_{
      "..."
    }
  }
excalibur$ ruby /tmp/a.rb
{:"xmlns:xhtml"=>"http://www.w3.org/1999/xhtml"}
{:"xmlns:xf"=>"http://www.w3.org/2002/xforms"}
<empty_element>
/tmp/a.rb:38: undefined local variable or method `xhmtl' for #<Object:0x7f1e7ce77358 @tagz=nil> (NameError)

-- 
Andrew S. Townley <ast@atownley.org>
http://atownley.org