modify attachments

app/models/attachment.rb

@@ -12,12 +12,12 @@
 
 class Attachment < ActiveRecord::Base
   has_paper_trail
-  attr_accessible :name, :datei, :datei_cache
+  attr_accessible :name, :datei, :datei_cache,:flag_titlepic
   belongs_to :thema
   mount_uploader :datei, AttachmentUploader
   validates :thema, :presence => true
   validates :name, :presence => true
-
+  belongs_to :parent, :polymorphic=>true
   def image?
     
  #   data_ext = datei.file.extension.downcase 

app/models/thema.rb

@@ -22,6 +22,7 @@ include Rails.application.routes.url_helpers
   validates :themengruppe, :presence => true
   validates :title, :presence => true
   validates :text, :presence => true
+  has_many :titlepics, :as=>:parent, :class_name=>'Attachment', :conditions=>{:flag_titlepic=>true}
   has_many :meetings, :as=>:parent
   has_many :documents, :as=>:parent
   scope :public, where(:isdraft=>false).includes(:themengruppe).where("themengruppen.public"=>true)