Update existing checklists

gistfile1.txt

function updateExistingChecklists(notification)
{
  //WAS A NEW ITEM ADDED?
  var new_item = new Notification(notification).addedChecklistItem();
  //IF IT WAS ADDED TO A CARD NAMED "Checklist Templates"
  if(new_item.checklist().card().name() == "Checklist Templates")
  {
    //LOOP THROUGH ALL CARDS ON THE BOARD
    new_item.checklist().card().board().cards().each(function(card)
    {
        //COPY THE NEW CHECKLIST TO THE CARD BUT WITH THE WORD " NEW" ON THE END
        new_item.checklist().card().copyChecklist(new_item.checklist().name()+" NEW",card);
        //GET A LIST OF OLD ITEMS FROM THE PREVIOUS CHECKLIST
        var old_items = card.checklist(new_item.checklist().name());
        //GRAB THE NEWLY ADDED CHECKLIST
        var new_checklist = card.checklist(new_item.checklist().name()+" NEW");
        //FOR EACH ITEM THAT WAS PREVIOUSLY PART OF THIS CHECKLIST ... 
        old_items.each(function(item)
        {
          //IF IT HAD ALREADY BEEN COMPLETED ... 
          if(item.isComplete())
            //MARK THE CORRESPONDING ITEM ON THE NEWLY ADDED CHECKLIST COMPLETE
            new_checklist.item(item.name()).markComplete())
        });
        //REMOVE THE OLD CHECKLIST
        card.removeChecklist(new_item.checklist().name());
        //RENAME THE NEW CHECKLIST TO THE ORIGINAL CHECKLIST NAME
        card.checklist(new_item.checklist().name()+" NEW").setName(new_item.checklist().name());
    });
  }
}