Xtensive.Orm.Tracking 7.1.4

Xtensive.Orm.Tracking

Summary

Provides tracking/auditing funtionality on Session/Domain level.

Prerequisites

DataObjects.Net 7.1.x or later (http://dataobjects.net)

Implementation

1. Include types from Xtensive.Orm.Tracking assembly into the domain:

  <Xtensive.Orm>
    <domains>
      <domain ... >
        <types>
          <add assembly="your assembly"/>
          <add assembly="Xtensive.Orm.Tracking"/>
        </types>
      </domain>
    </domains>
  </Xtensive.Orm>

2. To track changes on Session level obtain an instance of ISessionTrackingMonitor through Session.Services.Get<ISessionTrackingMonitor>() method; to track changes on Domain level (from all sessions) obtain an instance of IDomainTrackingMonitor through Domain.Services.Get<IDomainTrackingMonitor>() method
3. Subscribe to TrackingCompleted event. After each tracked transaction is committed you receive the TrackingCompletedEventArgs object.
4. TrackingCompletedEventArgs.Changes contains a collection of ITrackingItem objects, each of them represents a set of changes that occured to an Entity within the transaction committed.

Demo

First, subscribe to the TrackingCompleted event of ISessionTrackingMonitor / IDomainTrackingMonitor

var monitor = Domain.Services.Get<IDomainTrackingMonitor>();
monitor.TrackingCompleted += TrackingCompletedListener;

Then, do some changes to persistent entities

using (var session = Domain.OpenSession()) {
  using (var t = session.OpenTransaction()) {
    var e = new MyEntity(session);
    e.Text = "some text";
    t.Complete();
  }
}

And handle TrackingCompleted event call and do whatever you want with tracked changes.

private void TrackingCompletedListener(object sender, TrackingCompletedEventArgs e)
{
  foreach (var change in e.Changes) {
    Console.WriteLine(change.Key);
    Console.WriteLine(change.State);

    foreach (var value in change.ChangedValues) {
      Console.WriteLine(value.Field.Name);
      Console.WriteLine(value.OriginalValue);
      Console.WriteLine(value.NewValue);
    }
  }
}