/// <summary>
/// Normally we automatically generate this log in DbContext.SaveChanges function.
/// However, Identity Framework delete functions does not invoke our custom SaveChanges
/// method.
/// </summary>
/// <param name="operation">Name of operation DELETE/UPDATE ..etc</param>
/// <param name="entity">Entity to be logged</param>
/// <returns>RecordAuditLog object to be inserted.</returns>
private RecordAuditLog GenerateAuditLog(string operation, object entity)
{
RecordAuditLog log = new RecordAuditLog();
log.EntityName = entity.GetType().Name;
log.Operation = operation;
log.Content = this._xmlSerializer.SerializeToXML(entity);
log.CreatedBy = this._contextProvider.UserName;
log.CreatedOn = DateTime.UtcNow;
return(log);
}
public override int SaveChanges()
{
List <RecordAuditLog> auditLogs = new List <RecordAuditLog>();
foreach (DbEntityEntry entry in this.ChangeTracker.Entries())
{
ITrackableEntity trackableEntity = entry.Entity as ITrackableEntity;
IEntity entity = entry.Entity as IEntity;
if (entry.State == EntityState.Deleted && !(entry.Entity is ISafeToDeleteEntity))
{
RecordAuditLog log = new RecordAuditLog();
log.EntityName = entry.Entity.GetType().Name;
log.Operation = entry.State.ToString();
log.Content = this._xmlSerializer.SerializeToXML(entry.Entity);
log.CreatedBy = this._contextProvider.UserName;
log.CreatedOn = DateTime.UtcNow;
auditLogs.Add(log);
}
else if (entry.State == EntityState.Modified && trackableEntity != null)
{
trackableEntity.ModifiedOn = DateTime.UtcNow;
trackableEntity.ModifiedBy = this._contextProvider.UserName;
}
else if (entry.State == EntityState.Added && entity != null)
{
if (string.IsNullOrEmpty(entity.CreatedBy))
{
entity.CreatedBy = this._contextProvider.UserName;
}
if (entity.CreatedOn == default(DateTime))
{
entity.CreatedOn = DateTime.UtcNow;
}
}
}
if (auditLogs.Count > 0 && AuditLoggingEnabled)
{
this.Set <RecordAuditLog>().AddRange(auditLogs);
}
try
{
return(base.SaveChanges());
}
catch (DbEntityValidationException ex)
{
// Retrieve the error messages as a list of strings.
var errorMessages = ex.EntityValidationErrors
.SelectMany(x => x.ValidationErrors)
.Select(x => x.ErrorMessage);
// Join the list to a single string.
var fullErrorMessage = string.Join("; ", errorMessages);
// Combine the original exception message with the new one.
var exceptionMessage = string.Concat(ex.Message, " The validation errors are: ", fullErrorMessage);
// Throw a new DbEntityValidationException with the improved exception message.
throw new DbEntityValidationException(exceptionMessage, ex.EntityValidationErrors);
}
}
