validate domain ownership

app/models/domain.rb

@@ -34,6 +34,15 @@ class Domain < ActiveRecord::Base
     :minimum => 2, :maximum => 10, :message => "must have be at least 2, at most 10"}
   validates_associated :records
   validates :user_id, :presence => true
+  validate do # domain ownership
+    segments = name.split('.')
+    if segments.size > 2
+      parent = segments[1..-1].join('.')
+      unless Domain.exists?(:name => parent, :user_id => user_id)
+        errors.add :name, "issue, must create the domain named `#{parent}` first"
+      end
+    end
+  end
   
   def slave?; self.type == 'SLAVE' end
 

db/migrate/20111014194447_index_domains_user_id.rb

@@ -0,0 +1,5 @@
+class IndexDomainsUserId < ActiveRecord::Migration
+  def change
+    add_index :domains, :user_id
+  end
+end