save asset static file

app/models/asset.rb

@@ -9,6 +9,11 @@ class Asset
   has_grid_attachment :data, :required => true
   
   before_validation :setup_filename
+  after_save :save_static_file
+  
+  def url
+    "/assets/#{self.filename}"
+  end
   
   protected
   
@@ -18,4 +23,10 @@ class Asset
     end
   end
   
+  def save_static_file
+    f = File.new("#{RAILS_ROOT}/public/assets/#{self.filename}", "wb")
+    f.write(self.data.file.read)
+    f.close
+  end
+  
 end