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Customize the Data Storing Mechanism

  • 3 minutes to read

The Audit Trail Module stores audit records (AuditDataItem objects) in an application database. The SaveAuditTrailData event allows you to configure how this Module saves information. This event is raised when the Module commits an AuditDataItem object to the database. In this event handler, you can modify the SaveAuditTrailDataContext.AuditTrailDataItems (in .NET applications) or SaveAuditTrailDataEventArgs.AuditTrailDataItems (in .NET Framework applications) collection, and add new or remove unnecessary items. The following code demonstrates how to remove ObjectCreated records.

In .NET Applications

File: MySolution.Blazor.Server\Startup.cs, MySolution.Win\Startup.cs, MySolution.WebApi\Startup.cs

using DevExpress.Persistent.AuditTrail;
// ...
builder.Modules
    .AddAuditTrailXpo(o => {
        o.Events.OnCustomizeAuditOperationTypeFilter = context => {
            if (context.AuditOperationType == AuditOperationType.ObjectChanged ||
                context.AuditOperationType == AuditOperationType.ObjectCreated) {
                context.SaveAuditOperation = false;
            }
        };
    })

In .NET Framework Applications

File: MySolution.Win\Program.cs, MySolution.Web\Global.asax.cs

using DevExpress.Persistent.AuditTrail;
// ...
static class Program {
    // ...
    static void Main() {
        MySolutionWindowsFormsApplication application = new MySolutionWindowsFormsApplication();
        // ...
        AuditTrailService.Instance.SaveAuditTrailData += 
            new SaveAuditTrailDataEventHandler(Instance_SaveAuditTrailData);
        application.Setup();
        application.Start();
        // ...
    }
    static void Instance_SaveAuditTrailData(object sender, SaveAuditTrailDataEventArgs e) {
        for(int i = e.AuditTrailDataItems.Count - 1; i >= 0; i--) {
            var item = e.AuditTrailDataItems[i];
            if(item.OperationType == AuditOperationType.ObjectCreated) {
                e.AuditTrailDataItems.RemoveAt(i);
            }
        }
    }
}

Replace the Default Data Storing Mechanism with a Custom Mechanism

To do this, set the event’s SaveAuditTrailDataContext.Handled (in .NET applications) or SaveAuditTrailDataEventArgs.Handled (in .NET Framework applications) argument to true in the SaveAuditTrailData event handler.

In .NET Applications

File: MySolution.Blazor.Server\Startup.cs, MySolution.Win\Startup.cs, MySolution.WebApi\Startup.cs

using DevExpress.Persistent.AuditTrail;
// ...
builder.Modules
    .AddAuditTrailXpo(o => {
        o.Events.OnCustomizeAuditOperationTypeFilter = context => {
            // Save the data passed as the `context.AuditTrailDataItems` parameter
            context.Handled = true; // Disable the default data storing mechanism
        };
    })

In .NET Framework Applications

File: MySolution.Win\Program.cs, MySolution.Web\Global.asax.cs

using DevExpress.Persistent.AuditTrail;
// ...
static class Program {
    // ...
    static void Main() {
        MySolutionWindowsFormsApplication application = new MySolutionWindowsFormsApplication();
        // ...
        AuditTrailService.Instance.SaveAuditTrailData += 
            new SaveAuditTrailDataEventHandler(Instance_SaveAuditTrailData);
        application.Setup();
        application.Start();
        // ...
    }
    static void Instance_SaveAuditTrailData(object sender, SaveAuditTrailDataEventArgs e) {
        // Save the data passed as the `e.AuditTrailDataItems` parameter
        e.Handled = true; // Disable the default data storing mechanism
    }
}

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