From: "Andrew S. Townley" <ast@...>
Date: 2009-03-28T03:05:55+09:00
Subject: [PATCH] tagz-5.0.0 -- processing instruction support

Hi Ara,

I'm sure you're sick of me by now, but I've added processing instruction
support to tagz.  It may not suit your style, but I've tried to keep it
in the spirit of the library.

excalibur$ diff
-u /var/lib/gems/1.8/gems/tagz-5.0.0/lib/tagz.rb /tmp/tagz.rb
--- /var/lib/gems/1.8/gems/tagz-5.0.0/lib/tagz.rb	2009-03-24
11:58:05.000000000 +0000
+++ /tmp/tagz.rb	2009-03-27 18:01:11.000000000 +0000
@@ -15,27 +15,7 @@
   # open_tag
   #
     def tagz__ name, *argv, &block
-      options = argv.last.is_a?(Hash) ? argv.pop : {}
-      content = argv
-
-      unless options.empty?
-        attributes = ' ' << 
-          options.map do |key, value|
-            key = XChar.escape key.to_s
-            value = XChar.escape value.to_s
-            if value =~ %r/"/
-              raise ArgumentError, value if value =~ %r/'/
-              value = "'#{ value }'"
-            else
-              raise ArgumentError, value if value =~ %r/"/
-              value = "\"#{ value }\""
-            end
-            [key, value].join('=')
-          end.join(' ')
-      else
-        attributes = ''
-      end
-
+      attributes, content = process_attributes *argv, &block
       tagz.concat "<#{ name }#{ attributes }>"
 
       if content.empty?
@@ -68,6 +48,13 @@
       tagz.concat "</#{ tag }>"
     end
 
+  # processing instruction
+  #
+    def tagz_? name, *argv, &block
+      attributes, content = process_attributes *argv, &block
+      tagz.concat "<?#{ name }#{ attributes }?>"
+    end
+
   # access tagz doc and enclose tagz operations
   #
     def tagz document = nil, &block
@@ -94,6 +81,8 @@
     def method_missing m, *a, &b
       strategy =
         case m.to_s
+          when %r/^(.*[^?])_\?$/o
+            :processing_instruction
           when %r/^(.*[^_])_(!)?$/o
             :open_tag
           when %r/^_([^_].*)$/o
@@ -119,6 +108,9 @@
           m, bang = $1, $2
           b ||= lambda{} if bang
           tagz{ tagz__(m, *a, &b) }
+        when :processing_instruction
+          m = $1
+          tagz{ tagz_?(m, *a, &b) }
         when :close_tag
           m = $1
           tagz{ __tagz(m, *a, &b) }
@@ -135,6 +127,33 @@
       end
     end
 
+    def process_attributes *argv, &block
+      options = argv.last.is_a?(Hash) ? argv.pop : {}
+      content = argv
+      
+      attributes = nil
+
+      unless options.empty?
+        attributes = ' ' << 
+          options.map do |key, value|
+            key = XChar.escape key.to_s
+            value = XChar.escape value.to_s
+            if value =~ %r/"/
+              raise ArgumentError, value if value =~ %r/'/
+              value = "'#{ value }'"
+            else
+              raise ArgumentError, value if value =~ %r/"/
+              value = "\"#{ value }\""
+            end
+            [key, value].join('=')
+          end.join(' ')
+      else
+        attributes = ''
+      end
+
+      [ attributes, content ]
+    end
+
     class Document < ::String
       def Document.for other
         Document === other ? other : Document.new(other.to_s)

excalibur$ cat c.rb
require 'tagz'
include Tagz.globally

doc = 
  Tagz {
    xml_?(:version => "1.0")
    mypi_?(:arg1 => "foo")
    tagz_?("xml-stylesheet", :href => "classic.xsl", :type =>
"text/xml")
    test_!
  }

puts doc

excalibur$ ruby c.rb
<?xml version="1.0"?><?mypi arg1="foo"?><?xml-stylesheet type="text/xml"
href="classic.xsl"?><test/>
-- 
Andrew S. Townley <ast@atownley.org>
http://atownley.org