Save pages to generate page_parts when a layout is updated

app/models/design/layout.rb

@@ -10,6 +10,7 @@ class Layout < DesignFile
   embeds_many :layout_parts
   
   before_save :parse_layout
+  after_save :save_pages
 
   def content
     self.file.read.force_encoding("UTF-8") rescue ''
@@ -25,4 +26,8 @@ class Layout < DesignFile
     parse_body(self)
   end
 
+  def save_pages
+    self.design.pages.each(&:save)
+  end
+  
 end