Hi!

I have a website with a number of nodes that have child nodes. The main node has a property called "version" and depending on which of the child nodes are published this version number needs to be updated. 
This version is then included in some xml that is created via xslt.

I am using events to do this as follows..

Document.BeforePublish += new Document.PublishEventHandler(Document_BeforePublish);
  void Document_BeforePublish(Document sender, PublishEventArgs e)
        {
            switch (sender.ContentType.Alias)
            {
       case "NodeImLookingFor":
       //load the document with version property
                Document doc= new Document(sender.parentId); //the document needed is usually the parent, this has just been condensed down for demonstration purposes
               //grab the current version number            
        int newVersionNumber = Convert.ToInt32(trail.getProperty("version").Value) + 1;
              //update the version nyumber
             doc.getProperty("version").Value = newVersionNumber;
         
                doc.Publish(User.GetUser(0));           
                library.UpdateDocumentCache(sender.parentId);
                library.RefreshContent();
                
            }
break:
}