check uniqueness for item, layout and snippet

app/models/item.rb

@@ -15,6 +15,8 @@ class Item
   key :is_published, Boolean, :required => true, :default => true, :index => true
  
   validates_format_of :name, :with => /^[a-zA-Z-_]+$/
+  validates_uniqueness_of :name
+  
   belongs_to :parent, :class_name => "Item", :foreign_key => :parent_id
   many :children, :class_name => "Item", :foreign_key => :parent_id, :dependent => :destroy
   

app/models/layout.rb

@@ -9,5 +9,6 @@ class Layout
    many :children, :class_name => "Item", :foreign_key => "layout_id", :dependent => :nullify
    
    validates_format_of :name, :with => /^[a-zA-Z-_]+$/
+   validates_uniqueness_of :name
    
 end

app/models/snippet.rb

@@ -4,11 +4,12 @@ class Snippet
   
    key :name, String, :required => true, :index => true
    key :parent_name, String, :required => true, :index => true
-   key :parent_id, String, :required => true, :index => true
+   key :parent_id, ObjectId, :required => true, :index => true
    
    key_i18n :content, String
    
    before_validation :setup_default_value
+   validates_uniqueness_of :name, :scope => :parent_id
    
    protected