5.9.5.2. Viewing Snapshots

Viewing snapshots for arbitrary entities is possible using the com/haulmont/cuba/gui/app/core/entitydiff/diff-view.xml frame. For example:

<frame id="diffFrame"
      src="/com/haulmont/cuba/gui/app/core/entitydiff/diff-view.xml"
      width="100%"
      height="100%"/>

The snapshots should be loaded into the frame from the edit screen controller:

public class CustomerEditor extends AbstractEditor<Customer> {

  @Inject
  protected EntityDiffViewer diffFrame;

...
  @Override
  protected void postInit() {
      if (!PersistenceHelper.isNew(getItem())) {
          diffFrame.loadVersions(getItem());
      }
  }
}

The diff-view.xml frame shows the list of snapshots for the given entity, with an ability to compare them. The view for each snapshot includes the user, date and time. When a snapshot is selected from the list, the changes will be displayed compared to the previous snapshot. All attributes are marked as changed for the first snapshot. Selecting two snapshots shows the results of the comparison in a table.

The comparison table shows attribute names and their new values. When a row is selected, the detailed information on attribute changes across two snapshots is shown. Reference fields are displayed according to their instance name. When comparing collections, the new and removed elements are highlighted with green and red color respectively. Collection elements with changed attributes are displayed without highlighting. Changes to element positions are not recorded.