Audit.net data models example

Question

Does any one have a working example of how to added audit models to an existing project, for Audit.Net.

It is one fantastic component to use, and up until now, my team and I have gotten by with the standard JSON files, however, we'd like to migrate our current solution to our Xamarin application, and would like to store the auditing in the local SQLite database on the device.

However, the documentation for this project is somewhat lacking and there is no concise examples of how to get custom auditing working with Entity Framework.

We have worked through the MD files on the github repo, but we still cannot get auditing to work.

Another question, similar to this has been asked HERE, but there is no definitive example of what the Audit_{entity} table should look like, what fields it MUST contain, and how to set up relationships for it.

We tried to reverse engineer the JSON files into a relational structure, but at the time of asking this question, we have not gotten any auditing to write to the SQLite database.

Answer 1

Sorry about the documentation not helping too much, hope I (or anybody) can provide better documentation in the future.

I am assuming you are using EntityFramework to map your entities to a SQLite database, and you want to use the EF data provider to store the audits events in the same database, in Audit_{entity} tables.

There is no constraint on the schema you want to use for your Audit_{entity} tables, as long as you have a one-to-one relation between your {entity} table and its Audit_{entity} table. Then the mapping can be configured on several ways.

The recommendation for the Audit_{entity} tables is to have the same columns as the audited {entity} table, with any common additional column needed, like a User and a Date defined on an Interface.

So, if all your Audit_{entity} tables has the same columns/properties as its {entity}, and you added some common columns (defined on an interface), the configuration can be set like this:

public class User
{
    public int Id { get; set; }
    public string Name { get; set; }
}
public class Audit_User : IAudit
{
    public int Id { get; set; }
    public string Name { get; set; }
    // IAudit members:
    public string AuditUser { get; set; }
    public datetime AuditDate { get; set; }
    public string Action { get; set } // "Insert", "Update" or "Delete"
}

Audit.Core.Configuration.Setup()
    .UseEntityFramework(x => x
        .AuditTypeNameMapper(typeName => "Audit_" + typeName)
        .AuditEntityAction<IAudit>((ev, ent, auditEntity) =>
        {
            auditEntity.AuditDate = DateTime.UtcNow;
            auditEntity.AuditUser = evt.Environment.UserName;
            auditEntity.AuditAction = ent.Action;
        });

Note the interface is not mandatory, but using it makes the configuration cleaner. Also note you can make your Audit_{entity} inherit from your {entity} if you wanted to.

---

Update

Maybe my assumption at the beginning is incorrect and you are not auditing EF entities, but any other type of audit. If that's the case, what you are looking for is a Data Provider that stores the audit events into your SQLite database.

At the time being, there is no built-in data provider that stores to SQLite, and if there was one, it would store just the JSON representation of the event in one column (like the SQL/MySql providers). But it looks like you want to have a custom schema, so you will need to implement your own data provider.

Check the documentation here.

Here is a sample skeleton of a data provider:

public class SQLiteDataProvider : AuditDataProvider
{
    public override object InsertEvent(AuditEvent auditEvent)
    {
        // Insert the event into SQLite and return its ID
    }
    public override void ReplaceEvent(object eventId, AuditEvent auditEvent)
    {
        // Replace the event given its ID (only used for CreationPolicies InsertOnStartReplaceOnEnd and Manual)
    }
    // async implementation:
    public override async Task<object> InsertEventAsync(AuditEvent auditEvent)
    {
        // Asynchronously insert the event into SQLite and return its ID
    }
    public override async Task ReplaceEventAsync(object eventId, AuditEvent auditEvent)
    {
        // Asynchronously  replace the event given its ID 
    }
}

Then you just set it up with:

Audit.Core.Configuration.Setup()
    .UseCustomProvider(new SQLiteDataProvider());