traited.rb in manveru-innate-2009.02.25

- old
+ new

@@ -1,6 +1,31 @@
 module Innate
+  # Traited helps you doing configuration similar to class variables.
+  #
+  # It's built on a simple Hash, where keys are objects and the values the
+  # configuration.
+  # By using {Traited#ancestral_trait} you will get nicely inherited
+  # configuration, where keys later in the ancestors will take precedence.
+  #
+  # @usage
+  #   class Foo
+  #     include Innate::Traited
+  #     trait :hello => 'Hello'
+  #
+  #     def initialize
+  #       trait :hello => 'World!'
+  #     end
+  #
+  #     def show
+  #       [class_trait[:hello], trait[:hello], ancestral_trait[:hello]]
+  #     end
+  #   end
+  #
+  #   Foo.trait[:hello] # => "Hello"
+  #   foo = Foo.new
+  #   foo.trait[:hello] # => "World!"
+  #   foo.show          # => ["Hello", "World!", "World!"]
   module Traited
     TRAITS = {}
 
     def self.included(into)
       into.extend(self)
@@ -13,13 +38,40 @@
       else
         TRAITS[self] || {}
       end
     end
 
+    # Builds a trait from all the ancestors, closer ancestors overwrite distant
+    # ancestors
+    #
+    # class Foo
+    #   include Innate::Traited
+    #   trait :one => :eins, :first => :erstes
+    # end
+    #
+    # class Bar < Foo
+    #   trait :two => :zwei
+    # end
+    #
+    # class Foobar < Bar
+    #   trait :three => :drei, :first => :overwritten
+    # end
+    #
+    # Foobar.ancestral_trait
+    # # => {:three => :drei, :two => :zwei, :one => :eins, :first => :overwritten}
     def ancestral_trait
+      result = {}
+
       ancs = respond_to?(:ancestors) ? ancestors : self.class.ancestors
-      ancs.reverse.inject({}){|s,v|
-        v.respond_to?(:trait) ? s.update(v.trait) : s
-      }.merge(trait)
+      ancs.reverse_each do |anc|
+        result.update(anc.trait) if anc.respond_to?(:trait)
+      end
+
+      result.merge!(trait)
+    end
+
+    # trait for self.class if we are an instance
+    def class_trait
+      respond_to?(:ancestors) ? trait : self.class.trait
     end
   end
 end