Fixes #15: Unable to add parent-child links

app/models/post.rb

@@ -414,7 +414,7 @@ class Post < ActiveRecord::Base
     end
     
     def filter_metatags(tags)
-      metatags, tags = tags.partition {|x| x =~ /\A(?:pool|rating|fav):/}
+      metatags, tags = tags.partition {|x| x =~ /\A(?:pool|rating|fav|parent):/}
       apply_metatags(metatags)
       return tags
     end
@@ -422,6 +422,9 @@ class Post < ActiveRecord::Base
     def apply_metatags(tags)
       tags.each do |tag|
         case tag
+        when /^parent:(\d+)$/
+          self.parent_id = $1.to_i
+          
         when /^pool:(\d+)$/
           pool = Pool.find_by_id($1.to_i)
           add_pool!(pool) if pool

test/unit/post_test.rb

@@ -215,6 +215,20 @@ class PostTest < ActiveSupport::TestCase
       end
       
       context "tagged with a metatag" do
+        context "for a parent" do
+          setup do
+            @parent = Factory.create(:post)
+          end
+          
+          should "update the parent relationships for both posts" do
+            @post.update_attributes(:tag_string => "aaa parent:#{@parent.id}")
+            @post.reload
+            @parent.reload
+            assert_equal(@parent.id, @post.parent_id)
+            assert(@parent.has_children?)
+          end
+        end
+        
         context "for a pool" do
           context "id" do
             setup do