examples/state_machine.rb in volute-0.1.0 vs examples/state_machine.rb in volute-0.1.1

@@ -7,53 +7,55 @@
 $:.unshift(File.join(File.dirname(__FILE__), '..', 'lib'))
 
 require 'volute'
 
 #
-# our class
+# our classes
 
-class Book
-  include Volute
+module Bookshop
 
-  attr_accessor :stock
-  attr_accessor :discontinued
+  class Book
+    include Volute
 
-  attr_reader :state
+    attr_accessor :stock
+    attr_accessor :discontinued
+    attr_accessor :state
 
-  def initialize (stock)
-    @stock = stock
-    @discontinued = false
-    @state = :in_stock
+    def initialize (stock)
+      @stock = stock
+      @discontinued = false
+      @state = :in_stock
+    end
   end
 end
 
 #
-# a volute triggered for any 'set' operation on an attribute of book
+# volutes
 
-volute Book do
+volute Bookshop do
 
-  # object.volute_do_set(:state, x)
-  #   is equivalent to
-  # object.instance_variable_set(:@state, x)
+  volute :stock, :discontinued do
 
-  if object.stock <= 0
-    object.volute_do_set(
-      :state, object.discontinued ? :discontinued : :out_of_stock)
-  else
-    object.volute_do_set(
-      :state, :in_stock)
+    # anything in the module Bookshop that has an attribute :stock
+    # or :discontinued
+
+    if object.stock <= 0
+      object.state = object.discontinued ? :discontinued : :out_of_stock
+    else
+      object.state = :in_stock
+    end
   end
 end
 
 #
 # trying
 
-emma = Book.new(10)
+emma = Bookshop::Book.new(10)
 
-emma.stock = 2
+emma.stock -= 8
 p emma.state # => :in_stock
 
-emma.stock = 0
+emma.stock -= 2
 p emma.state # => :out_of_stock
 
 emma.discontinued = true
 p emma.state # => :discontinued