has_value and has_collection now accept option :extend

lib/valuable.rb

@@ -157,10 +157,13 @@ def defaults
     def has_value(name, options={})
       Valuable::Utils.check_options_validity(self.class.name, name, options)
 
+      options[:extend] = [options[:extend]].flatten.compact
+
       name = name.to_sym
       _attributes[name] = options 
-
-      create_accessor_for(name)
+
+      create_accessor_for(name, options[:extend])
+
       create_question_for(name) if options[:klass] == :boolean
       create_negative_question_for(name, options[:negative]) if options[:klass] == :boolean && options[:negative]
 
@@ -200,12 +203,23 @@ def sudo_alias( alias_name, method_name )
       end
     end
 
-    # creates a simple accessor method named after the attribute
-    def create_accessor_for(name)
+    # creates an accessor method named after the 
+    # attribute... can be used as a chained setter, 
+    # as in:
+    #
+    #     whitehouse.windows(5).doors(4).oval_rooms(1)
+    #
+    # If NOT used as a setter, returns the value,
+    # extended by the modules listed in the second 
+    # parameter.
+    def create_accessor_for(name, extensions)
       define_method name do |*args|
-
-        if args.length == 0 
-          attributes[name]
+        if args.length == 0
+          attributes[name].tap do |out|
+            extensions.each do |extension|
+              out.extend( extension )
+            end
+          end
         else
           send("#{name}=", *args)
           self
@@ -270,10 +284,11 @@ def has_collection(name, options = {})
       options[:item_klass] = options[:klass] if options[:klass]
       options[:klass] = :collection
       options[:default] = []
+      options[:extend] = [options[:extend]].flatten.compact
 
       _attributes[name] = options 
 
-      create_accessor_for(name)
+      create_accessor_for(name, options[:extend])
       create_setter_for(name)
 
       sudo_alias options[:alias], name if options[:alias]

lib/valuable/utils.rb

@@ -116,7 +116,7 @@ def klass_options
     end
 
     def known_options
-      [:klass, :default, :negative, :alias, :parse_with]
+      [:klass, :default, :negative, :alias, :parse_with, :extend]
     end
 
     # this helper raises an exception if the options passed to has_value

test/extending_test.rb

@@ -0,0 +1,30 @@
+$: << File.expand_path(File.dirname(__FILE__) + '/../lib')
+
+require 'test/unit'
+require 'valuable.rb'
+
+module BookCollection
+end
+
+module PirateFormatter
+  def to_pirate
+    "#{self}, ARRRGGGhhhhh!"
+  end
+end
+
+class Series < Valuable
+  has_collection :books, :extend => BookCollection
+  has_value :name, :extend => PirateFormatter
+end
+
+class ExtendingTest < Test::Unit::TestCase
+  def test_that_collections_are_extended
+    assert Series.new.books.is_a?(BookCollection)
+  end
+
+  def test_that_values_are_extended
+    assert_equal 'Walk The Plank, ARRRGGGhhhhh!', Series.new(:name => 'Walk The Plank').name.to_pirate
+  end
+
+end
+