domain#name_reversed cache for indexing and searching and domain ownership validation accounting for permissions

app/models/domain.rb

@@ -50,7 +50,7 @@ class Domain < ActiveRecord::Base
     errors[:name] = "cannot be a TLD or a reserved domain" if Tld.include?(name)
 
     # if parent domain is on our system, the user must own it
-    if parent_domain.present? && parent_domain.user_id != user_id
+    if parent_domain.present? && user.cannot?(:manage, parent_domain)
       errors[:name] = "issue, the parent domain `#{parent_domain.name}` is registered to another user"
     end
   end
@@ -74,6 +74,10 @@ class Domain < ActiveRecord::Base
     a_records.build(:content => ip) if ip.present?
   end
   
+  before_save do
+    self.name_reversed = name.reverse if name_changed?
+  end
+  
   before_validation(:on => :update) do
     if name_changed?
       name_was_pattern = /#{Regexp.escape(name_was)}$/

app/models/user.rb

@@ -24,4 +24,10 @@ class User < ActiveRecord::Base
     "#{first_name} #{last_name}"
   end
   
+  delegate :can?, :cannot?, :to => :ability
+  
+  def ability
+    @ability ||= Ability.new(self)
+  end
+  
 end

db/migrate/20120112175527_add_name_reversed_to_domains.rb

@@ -0,0 +1,15 @@
+class AddNameReversedToDomains < ActiveRecord::Migration
+  def up
+    # used for "%" search indexing in an ancestry fashion (materialized path pattern)
+    # http://dev.mysql.com/doc/refman/5.0/en/mysql-indexes.html
+    add_column :domains, :name_reversed, :string, :limit => 255
+    execute "UPDATE domains SET name_reversed = REVERSE(name)"
+    change_column :domains, :name_reversed, :string, :limit => 255, :null => false
+    add_index :domains, :name_reversed
+  end
+  
+  def down
+    remove_index :domains, :column => :name_reversed
+    remove_column :domains, :name_reversed
+  end
+end

spec/models/domain_spec.rb

@@ -46,6 +46,11 @@ describe Domain do
     domain.should be_valid
   end
   
+  it "has parent_domain" do
+    subdomain = build(:domain, :user => other_user, :name => "x.#{domain.name}")
+    subdomain.parent_domain.should == domain
+  end
+  
   it "validates ownership" do
     domain.name = 'co.uk'
     domain.should have(1).errors_on(:name)
@@ -53,9 +58,13 @@ describe Domain do
     domain.name = 'clyfe.ro'
     domain.should be_valid
 
-    # stub a parent domain on another user account
-    mock_domain = mock(:user_id => domain.user_id + 1, :name => 'x')
-    Domain.stub_chain('find_by_name').and_return(mock_domain)
+    # stub a parent domain on another user account, with no permissions present
+    mock_domain = mock(
+      :user_id => third_user.id,
+      :user => third_user,
+      :name => 'x'
+    )
+    Domain.stub(:find_by_name).and_return(mock_domain)
     domain.should have(1).errors_on(:name)
   end
 
@@ -66,4 +75,9 @@ describe Domain do
     joins.should == [[:permissions, Arel::Nodes::OuterJoin]]
   end
   
+  it "has reversed name" do
+    domain.name_reversed.should be_present
+    domain.name_reversed.should == domain.name.reverse
+  end
+  
 end

spec/support/shared_context/data.rb

@@ -5,6 +5,9 @@ shared_context "data" do
 
   let(:other_user){create(:user)}
   let(:other_user_ability){Ability.new(:user => other_user)}
+
+  let(:third_user){create(:user)}
+  let(:third_user_ability){Ability.new(:user => third_user)}
   
   let(:domain){
     domain = build(:domain, :user => user)