I have create an simple diagram and on every node create or link create am saving data into a model, which looks like below example JSON. now when an user is doing undo/Redo actions how do i Add or remove data from my model, is there any method that stores Undo/redo data.

{"nodes":[{"id":0,"shape":"Container","text":"Test App","color":"#FFF8DC","children":[1,2,3,4,5,6]},{"id":1,"shape":"Delay","text":"A","color":"#66CDAA"},{"id":2,"shape":"Rectang
le","text":"B","color":"#FFB6A5"},{"id":3,"shape":"Arrow7","text":"C","color":"#
C8A2C8"},{"id":4,"shape":"DataTransmition","text":"D","color":"#FF91A4"},{"id":5
,"shape":"Actor","text":"E","color":"#B0E2FF"},{"id":6,"shape":"ExternalOrganiza
tion","text":"F","color":"#BA55D3"}],"links":[{"origin":1,"target":2},{"origin":1,"target":3},{"origin":1,"target":4},{"origin":1,"target":5},{"origin":1,"target":6}]}

I have events to itemAdded and itemRemoved for both but on undo the events are triggring but not in redo?

When i add nodes or links itemAdded is triggering but not only in Redo.



   case 'itemAdded':
        console.log("Item Added:", args);
        console.log("sender", sender);
        if (args.node) {
          console.log("Added Node:", args.node);
        }
        if (args.link) {
          console.log("Added Link:", args.link);
        }
        break;
      case 'itemRemoved':
        console.log("Item Removed:", args);
        console.log("sender", sender);
        if (args.node) {
          console.log("Deleted Node:", args.node);
        }
        if (args.link) {
          console.log("Deleted Link:", args.link);
        }
        break;