Added the #subscript helper

CHANGES

@@ -1,5 +1,8 @@
 == CHANGES
 
+0.3.1
+  * Added the #subscript helper to the CommandNode class
+
 0.3.0
   * Resolve problems on Ruby 1.9.1 with ImageNode#read_source. Peter uses IO#getc, which returns a String on Ruby 1.9.1, not a Integer, so I replaced with getbyte. [clbustos]
   * Deleted duplicated definition of ImageNode#style= with attr_writer and def. [clbustos]

lib/rtf/node.rb

@@ -394,6 +394,21 @@ def underline
          end
       end
 
+      # This method provides a short cut means of creating a subscript command
+      # node. The method accepts a block that will be passed a single parameter
+      # which will be a reference to the subscript node created. After the
+      # block is complete the subscript node is appended to the end of the
+      # child nodes on the object that the method is call against.
+      def subscript
+         style           = CharacterStyle.new
+         style.subscript = true
+         if block_given?
+            apply(style) {|node| yield node}
+         else
+            apply(style)
+         end
+      end
+
       # This method provides a short cut means of creating a superscript command
       # node. The method accepts a block that will be passed a single parameter
       # which will be a reference to the superscript node created. After the
@@ -1662,4 +1677,4 @@ def to_rtf
          text.string
       end
    end # End of the Document class.
-end # End of the RTF module.
+end # End of the RTF module.

test/command_node_test.rb

@@ -156,6 +156,11 @@ def test_style
       assert(node.prefix == '\super')
       assert(node.suffix == nil)
       assert(node == root[-1])
+
+      node = root.subscript
+      assert(node.prefix == '\sub')
+      assert(node.suffix == nil)
+      assert(node == root[-1])
    end
 
    # Test text node addition.