gistfile1.cs

public static Boolean IsDirtyEntity(this ISession session, Object entity)
{
    return (DirtyPropertiesOf(session, entity).Any());
}

public static IEnumerable<string> DirtyPropertiesOf(this ISession session, Object entity)
{
    String className = NHibernateProxyHelper.GuessClass(entity).FullName;

    ISessionImplementor sessionImpl = session.GetSessionImplementation();

    IPersistenceContext persistenceContext = sessionImpl.PersistenceContext;

    IEntityPersister persister = sessionImpl.Factory.GetEntityPersister(className);

    EntityEntry oldEntry = sessionImpl.PersistenceContext.GetEntry(entity);


    if ((oldEntry == null) && (entity is INHibernateProxy))
    {
        INHibernateProxy proxy = entity as INHibernateProxy;

        Object obj = sessionImpl.PersistenceContext.Unproxy(proxy);

        oldEntry = sessionImpl.PersistenceContext.GetEntry(obj);
    }


    if (oldEntry != null)
    {
        Object[] oldState = oldEntry.LoadedState;

        Object[] currentState = persister.GetPropertyValues(entity, sessionImpl.EntityMode);

        Int32[] dirtyProps = persister.FindDirty(currentState, oldState, entity, sessionImpl);
        
        return dirtyProps != null ? persister.PropertyNames.Where((value, index) => dirtyProps.Contains(index)) : new List<string>();
    }

    return new List<string>();
    
}

public static Boolean IsDirtyProperty(this ISession session, Object entity, String propertyName)
{
    String className = NHibernateProxyHelper.GuessClass(entity).FullName;

    ISessionImplementor sessionImpl = session.GetSessionImplementation();

    IPersistenceContext persistenceContext = sessionImpl.PersistenceContext;

    IEntityPersister persister = sessionImpl.Factory.GetEntityPersister(className);

    EntityEntry oldEntry = sessionImpl.PersistenceContext.GetEntry(entity);


    if ((oldEntry == null) && (entity is INHibernateProxy))
    {
        INHibernateProxy proxy = entity as INHibernateProxy;

        Object obj = sessionImpl.PersistenceContext.Unproxy(proxy);

        oldEntry = sessionImpl.PersistenceContext.GetEntry(obj);
    }


    Object[] oldState = oldEntry.LoadedState;

    Object[] currentState = persister.GetPropertyValues(entity, sessionImpl.EntityMode);

    Int32[] dirtyProps = persister.FindDirty(currentState, oldState, entity, sessionImpl);

    Int32 index = Array.IndexOf(persister.PropertyNames, propertyName);


    Boolean isDirty = (dirtyProps != null) ? (Array.IndexOf(dirtyProps, index) != -1) : false;


    return (isDirty);
}


public static Object GetOriginalEntityProperty(this ISession session, Object entity, String propertyName)
{
    String className = NHibernateProxyHelper.GuessClass(entity).FullName;

    ISessionImplementor sessionImpl = session.GetSessionImplementation();

    IPersistenceContext persistenceContext = sessionImpl.PersistenceContext;

    IEntityPersister persister = sessionImpl.Factory.GetEntityPersister(className);

    EntityEntry oldEntry = sessionImpl.PersistenceContext.GetEntry(entity);


    if ((oldEntry == null) && (entity is INHibernateProxy))
    {
        INHibernateProxy proxy = entity as INHibernateProxy;

        Object obj = sessionImpl.PersistenceContext.Unproxy(proxy);

        oldEntry = sessionImpl.PersistenceContext.GetEntry(obj);
    }


    Object[] oldState = oldEntry.LoadedState;

    Object[] currentState = persister.GetPropertyValues(entity, sessionImpl.EntityMode);

    Int32[] dirtyProps = persister.FindDirty(currentState, oldState, entity, sessionImpl);

    Int32 index = Array.IndexOf(persister.PropertyNames, propertyName);


    Boolean isDirty = (dirtyProps != null) ? (Array.IndexOf(dirtyProps, index) != -1) : false;


    return ((isDirty == true) ? oldState[index] : currentState[index]);
}