[Question] Json data using ef core

First of all, I may be wrong, sorry in advance. I want to use web api audit and ef core audit. I’m using a customized “provider” as far as I can see from the examples. I learned that “web api audit” will not be used with “ef core audit” and I switched to “sql data provider”. I am currently using ef core by default in my project.

public class MyCustomDataProvider : AuditDataProvider
{
    private readonly SqlDataProvider _webApiEventsDataProvider;
    private readonly SqlDataProvider _efEventsDataProvider;

    public MyCustomDataProvider(Action<ISqlServerProviderConfigurator> webApiConfig,
        Action<ISqlServerProviderConfigurator> efConfig)
    {
        _webApiEventsDataProvider = new SqlDataProvider(webApiConfig);
        _efEventsDataProvider = new SqlDataProvider(efConfig);
    }

    public override object InsertEvent(AuditEvent auditEvent)
    {
        return GetDataProvider(auditEvent).InsertEvent(auditEvent);
    }

    public override async Task<object> InsertEventAsync(AuditEvent auditEvent)
    {
        return await GetDataProvider(auditEvent).InsertEventAsync(auditEvent);
    }

    private SqlDataProvider GetDataProvider(AuditEvent auditEvent)
    {
        return auditEvent switch
        {
            AuditEventWebApi _ => _webApiEventsDataProvider,
            AuditEventEntityFramework _ => _efEventsDataProvider,
            _ => throw new ArgumentException("Audit.Net provider is null")
        };
    }
}

The first question I want to ask now is;

Since I use ef core by default, does it make sense for me to use a different “provider” again? How to use web api audit with ef core audit?

 public static void UseSettingsAudit(this IApplicationBuilder app, IConfiguration configuration)
    {
        string connectionString = configuration.GetConnectionString("DefaultConnection");

        _ = Audit.Core.Configuration.Setup()
            .UseCustomProvider(new MyCustomDataProvider(api => api.ConnectionString(connectionString)
                    .Schema("dbo")
                    .TableName("MyAuditWebApi")
                    .IdColumnName("Id")
                    .JsonColumnName("AuditData")
                    .CustomColumn("AuditDate", _ => DateTime.Now),
                ef => ef.ConnectionString(connectionString)
                    .Schema("dbo")
                    .TableName("MyAuditEFCore")
                    .IdColumnName("Id")
                    .CustomColumn("TableName", auditEvent => auditEvent.GetEntityFrameworkEvent().Entries[0].Table)
                    .CustomColumn("TableId",
                        ev => Convert.ToInt32(ev.GetEntityFrameworkEvent().Entries[0].PrimaryKey.FirstOrDefault()
                            .Value))
                    .CustomColumn("UserName", auditEvent => "DOLDURULACAK")
                    .CustomColumn("AuditData", auditEvent =>
                    {
                        var entries = auditEvent.GetEntityFrameworkEvent().Entries[0];

                        object data = entries.Action is "Update" ? entries.Changes : entries.ColumnValues;

                        return JsonSerializer.Serialize(data, new JsonSerializerOptions
                        {
                            Encoder = JavaScriptEncoder.UnsafeRelaxedJsonEscaping
                        });
                    })
                    .CustomColumn("Action", ev => ev.GetEntityFrameworkEvent().Entries[0].Action)
                    .CustomColumn("AuditDate", e => DateTime.Now)));
    }

I’m getting “connectionstring” again, transferring it to the provider or something, it didn’t make sense to me. I already use ef core by default.

my second question;

you’ve probably seen it. With .net 7, the json column feature came. As far as I understand from the documents, a json column query is created over the classes. to do this i need to create classes for my model. Of course, how do I query the dynamically saved data with constants, there is a little problem there.

https://learn.microsoft.com/en-us/ef/core/what-is-new/ef-core-7.0/whatsnew

By the way your libraries are very good. thank you for everything. I guess there is no problem with saving, there is a problem with queries, at least for me.

[thepirat000]

@mansurdegirmenci Note that the overload with the guard condition for Custom Columns in SqlServer data provider was added in version 20.2.0

[thepirat000]

You can add a parameterless constructor to the entity classes (CustomJsonEntry, CustomJsonEntryChange) it shouldn’t be a problem. the custom constructors were only for making the configuration shorter.

For the DbContext constructor issue, I think you have some options:

1. If it’s OK for you, you can just remove the .UseDbContext() call, so the same DbContext instance will be used to store the audits.

or

1. You can use the overload .UseDbContext(Func<AuditEventEntityFramework, DbContext>) that let you create the DbContext instance for each event, for example using the HttpContextAccessor to get the DbContext from the service provider:

// in your startup.cs

public void ConfigureServices(IServiceCollection services)
{
    services.AddDbContext<DataListContext>(opt => opt...);
    services.AddHttpContextAccessor();
    // ...
}

public void Configure(IApplicationBuilder app, IHostingEnvironment env, IHttpContextAccessor httpContextAccessor)
{
    Audit.Core.Configuration.Setup()
        .UseCustomProvider(new MyCustomDataProvider(api => api
                ...,
            ef => ef
                .UseDbContext(_ => httpContextAccessor.HttpContext.RequestServices.GetService<DataListContext>())
                .DisposeDbContext()
                .AuditTypeExplicitMapper(...));
    // ...
}

or

1. Store the DbContextOptions you get in the constructor of your DbContext, and use it to generate a new DbContext for the audit reusing the DbContextOptions.

public partial class DataListContext : AuditIdentityDbContext<AspNetUser, AspNetRole, int>
{ 
    private readonly DbContextOptions<MyContext> _options;

    public MyContext CreateAuditDbContext() => new MyContext(_options);

    public DataListContext(DbContextOptions<DataListContext> options) : base(options)
    {
        _options = options;
    }
}

// On your startup.cs, configure how to obtain the audit DbContext instance:
        .UseDbContext(ev => ((DataListContext)ev.GetEntityFrameworkEvent().GetDbContext()).CreateAuditDbContext())
        .DisposeDbContext()
        ...