move self.type to convertible

lib/jekyll/convertible.rb

@@ -106,6 +106,16 @@ module Jekyll
       defaults.merge(data).deep_merge(further_data)
     end
 
+    def type
+      if is_a?(Post)
+        :post
+      elsif is_a?(Page)
+        :page
+      elsif is_a?(Draft)
+        :draft
+      end
+    end
+
     # Recursively render layouts
     #
     # layouts - a list of the layouts

lib/jekyll/draft.rb

@@ -13,10 +13,6 @@ module Jekyll
       name =~ MATCHER
     end
 
-    def type
-      :draft
-    end
-
     # Get the full path to the directory containing the draft files
     def containing_dir(source, dir)
       File.join(source, dir, '_drafts')

lib/jekyll/page.rb

@@ -34,10 +34,6 @@ module Jekyll
       end
     end
 
-    def type
-      :page
-    end
-
     # The generated directory into which the page will be placed
     # upon generation. This is derived from the permalink or, if
     # permalink is absent, we be '/'

lib/jekyll/post.rb

@@ -69,10 +69,6 @@ module Jekyll
       self.populate_tags
     end
 
-    def type
-      :post
-    end
-
     def published?
       if self.data.has_key?('published') && self.data['published'] == false
         false