Commit 1d1d3b2

@@ -0,0 +1,26 @@
+module Scale
+  module Node
+    def children
+      @children ||= []
+    end
+
+    def add(node)
+      children.push(node)
+    end
+
+    def to_xml
+      builder = Nokogiri::XML::Builder.new do |xml|
+        append_to(xml)
+      end
+      builder.to_xml
+    end
+
+    def append_to(xml)
+      xml.send(xml_tag.to_sym, attributes) do
+        children.each do |node|
+          node.append_to(xml)
+        end
+      end
+    end
+  end
+end

@@ -1,13 +1,19 @@
 module Scale
   class Rectangle
+    include Node
+
     def initialize(width: nil, height: nil, fill: nil)
       @width = width
       @height = height
       @fill = fill
     end
 
-    def append_to(builder)
-      builder.rect(width: @width, height: @height, fill: @fill)
+    def xml_tag
+      :rect
+    end
+
+    def attributes
+      { width: @width, height: @height, fill: @fill }
     end
   end
 end

@@ -2,34 +2,19 @@ require 'nokogiri'
 
 module Scale
   class SVG
+    include Node
     attr_accessor :width, :height
 
     def initialize(width: nil, height: nil)
       @width, @height = width, height
-      @children = []
     end
 
-    def add(node)
-      @children.push(node)
-    end
-
-    def to_xml
-      builder = Nokogiri::XML::Builder.new do |xml|
-        append_to(xml)
-      end
-      builder.to_xml
-    end
+    private
 
-    def append_to(xml)
-      xml.svg(attributes) do
-        @children.each do |node|
-          node.append_to(xml)
-        end
-      end
+    def xml_tag
+      :svg
     end
 
-    private
-
     def attributes
       attributes = {
         version: "1.1", 

@@ -1,4 +1,5 @@
 require "scale/version"
+require "scale/node"
 require "scale/svg"
 require "scale/rectangle"