public class BaseEntity : IBaseEntity { [JsonIgnore] int Id { get; set; } [JsonIgnore] string? Audit { get; set; } }
public class AuditSourceValues { [JsonProperty("hn")] public string? HostName { get; set; } [JsonProperty("mn")] public string? MachineName { get; set; } [JsonProperty("rip")] public string? RemoteIpAddress { get; set; } [JsonProperty("lip")] public string? LocalIpAddress { get; set; } [JsonProperty("ua")] public string? UserAgent { get; set; } [JsonProperty("an")] public string? ApplicationName { get; set; } [JsonProperty("av")] public string? ApplicationVersion { get; set; } [JsonProperty("cn")] public string? ClientName { get; set; } [JsonProperty("cv")] public string? ClientVersion { get; set; } [JsonProperty("o")] public string? Other { get; set; } }
public class EntityAudit<TEntity> { [JsonProperty("type")] [JsonConverter(typeof(StringEnumConverter))] public EntityEventType EventType { get; set; } [JsonProperty("user", NullValueHandling = NullValueHandling.Include)] public int? ActorUserId { get; set; } [JsonProperty("at")] public DateTime ActDateTime { get; set; } [JsonProperty("sources")] public AuditSourceValues? AuditSourceValues { get; set; } [JsonProperty("newValues", NullValueHandling = NullValueHandling.Include)] public TEntity NewEntity { get; set; } = default!; public string? SerializeJson() { return JsonSerializer.Serialize(this, options: new JsonSerializerOptions { WriteIndented = false, IgnoreNullValues = true }); } }
دقت کنید که این کلاس به صورت جنریک تعریف شده است تا اگر بعدا بخواهیم آن را Deserialize کنیم و مثلا از آن API بسازیم، یا استفادهی خاصی را از آن داشته باشیم، بهراحتی به Entity مد نظر تبدیل شود. در این مقاله فقط به ذخیرهی آن پرداخته میشود و استفاده از این فیلد که به راحتی و با کمک DbFunctionها در Entity Framework قابل انجام است به خواننده واگذار میشود.
public enum EntityEventType { Create = 0, Update = 1, Delete = 2 }
public interface IAuditSourcesProvider { AuditSourceValues GetAuditSourceValues(); }
public class AuditSourcesProvider : IAuditSourcesProvider { protected readonly IHttpContextAccessor HttpContextAccessor; public AuditSourcesProvider(IHttpContextAccessor httpContextAccessor) { HttpContextAccessor = httpContextAccessor; } public virtual AuditSourceValues GetAuditSourceValues() { var httpContext = HttpContextAccessor.HttpContext; return new AuditSourceValues { HostName = GetHostName(httpContext), MachineName = GetComputerName(httpContext), LocalIpAddress = GetLocalIpAddress(httpContext), RemoteIpAddress = GetRemoteIpAddress(httpContext), UserAgent = GetUserAgent(httpContext), ApplicationName = GetApplicationName(httpContext), ClientName = GetClientName(httpContext), ClientVersion = GetClientVersion(httpContext), ApplicationVersion = GetApplicationVersion(httpContext), Other = GetOther(httpContext) }; } protected virtual string? GetUserAgent(HttpContext httpContext) { return httpContext.Request?.Headers["User-Agent"].ToString(); } protected virtual string? GetRemoteIpAddress(HttpContext httpContext) { return httpContext.Connection?.RemoteIpAddress?.ToString(); } protected virtual string? GetLocalIpAddress(HttpContext httpContext) { return httpContext.Connection?.LocalIpAddress?.ToString(); } protected virtual string GetHostName(HttpContext httpContext) { return httpContext.Request.Host.ToString(); } protected virtual string GetComputerName(HttpContext httpContext) { return Environment.MachineName; } protected virtual string? GetApplicationName(HttpContext httpContext) { return Assembly.GetEntryAssembly()?.GetName().Name; } protected virtual string? GetApplicationVersion(HttpContext httpContext) { return Assembly.GetEntryAssembly()?.GetName().Version.ToString(); } protected virtual string? GetClientVersion(HttpContext httpContext) { return httpContext.Request?.Headers["client-version"]; } protected virtual string? GetClientName(HttpContext httpContext) { return httpContext.Request?.Headers["client-name"]; } protected virtual string? GetOther(HttpContext httpContext) { return null; } }
حالا برای تامین اطلاعات کلاس EntityAudit کار مشابهی میکنیم. ابتدا اینترفیس IEntityAuditProvider را به صورت زیر تعریف میکنیم:
public interface IEntityAuditProvider { string? GetAuditValues(EntityEventType eventType, object? entity, string? previousJsonAudit = null); }
و سپس کلاس EntityAuditProvider را ایجاد میکنیم:
public class EntityAuditProvider : IEntityAuditProvider { private readonly IHttpContextAccessor _httpContextAccessor; private readonly IAuditSourcesProvider _auditSourcesProvider; #region Constructor Injections public EntityAuditProvider(IHttpContextAccessor httpContextAccessor, IAuditSourcesProvider auditSourcesProvider) { _httpContextAccessor = httpContextAccessor; _auditSourcesProvider = auditSourcesProvider; } #endregion public virtual string? GetAuditValues(EntityEventType eventType, object? newEntity, string? previousJsonAudit = null) { var httpContext = _httpContextAccessor.HttpContext; int? userId; var user = httpContext.User; if (!user.Identity.IsAuthenticated) userId = null; else userId = user.Claims.Where(x => x.Type == "UserID").Select(x => x.Value).First().ToInt(); var auditSourceValues = _auditSourcesProvider.GetAuditSourceValues(); var auditJArray = new JArray(); // Update & Delete if (eventType == EntityEventType.Update || eventType == EntityEventType.Delete) { auditJArray = JArray.Parse(previousJsonAudit!); } // Delete => No NewValues if (eventType == EntityEventType.Delete) { newEntity = null; } JObject newAuditJObject = JObject.FromObject(new EntityAudit<object?> { EventType = eventType, ActorUserId = userId, ActDateTime = DateTime.Now, AuditSourceValues = auditSourceValues, NewEntity = newEntity }, new JsonSerializer { NullValueHandling = NullValueHandling.Ignore, Formatting = Formatting.None }); auditJArray.Add(newAuditJObject); return auditJArray.SerializeToJson(true); } }
public class AuditSaveChangesInterceptor : SaveChangesInterceptor { private readonly IEntityAuditProvider _entityAuditProvider; #region Constructor Injections public AuditSaveChangesInterceptor(IEntityAuditProvider entityAuditProvider) { _entityAuditProvider = entityAuditProvider; } #endregion public override InterceptionResult<int> SavingChanges(DbContextEventData eventData, InterceptionResult<int> result) { ApplyAudits(eventData.Context.ChangeTracker); return base.SavingChanges(eventData, result); } public override ValueTask<InterceptionResult<int>> SavingChangesAsync(DbContextEventData eventData, InterceptionResult<int> result, CancellationToken cancellationToken = new CancellationToken()) { ApplyAudits(eventData.Context.ChangeTracker); return base.SavingChangesAsync(eventData, result, cancellationToken); } private void ApplyAudits(ChangeTracker changeTracker) { ApplyCreateAudits(changeTracker); ApplyUpdateAudits(changeTracker); ApplyDeleteAudits(changeTracker); } private void ApplyCreateAudits(ChangeTracker changeTracker) { var addedEntries = changeTracker.Entries() .Where(x => x.State == EntityState.Added); foreach (var addedEntry in addedEntries) { if (addedEntry.Entity is IBaseEntity entity) { entity.Audit = _entityAuditProvider.GetAuditValues(EntityEventType.Create, entity); } } } private void ApplyUpdateAudits(ChangeTracker changeTracker) { var modifiedEntries = changeTracker.Entries() .Where(x => x.State == EntityState.Modified); foreach (var modifiedEntry in modifiedEntries) { if (modifiedEntry.Entity is IBaseEntity entity) { var eventType = entity.IsArchived ? EntityEventType.Delete : EntityEventType.Update; // Maybe Soft Delete entity.Audit = _entityAuditProvider.GetAuditValues(eventType, entity, entity.Audit); } } } private void ApplyDeleteAudits(ChangeTracker changeTracker) { var deletedEntries = changeTracker.Entries() .Where(x => x.State == EntityState.Deleted); foreach (var modifiedEntry in deletedEntries) { if (modifiedEntry.Entity is IBaseEntity entity) { entity.Audit = _entityAuditProvider.GetAuditValues(EntityEventType.Delete, entity, entity.Audit); } } } }
و سپس آن را به سیستم معرفی میکنیم:
services.AddDbContext<ATADbContext>((serviceProvider, options) => { options .UseSqlServer(...) // Interceptors var entityAuditProvider = serviceProvider.GetRequiredService<IEntityAuditProvider>(); options.AddInterceptors(new AuditSaveChangesInterceptor(entityAuditProvider)); });
نمونهی کامل فیلد Audit که در JsonFormatter قرار داده شده است، بعد از ایجاد شدن و یکبار آپدیت و سپس حذف نرم رکورد:
[ { "type":"Create", "user":1, "at":"2020-11-24T23:05:54.2692711+03:30", "sources":{ "hn":"localhost:44398", "mn":"DESKTOP-N1GAV2U", "rip":"::1", "lip":"::1", "ua":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.198 Safari/537.36", "an":"Server.Api", "av":"1.0.0.0" }, "newValues":{ "Name":"Farshad" } }, { "type":"Update", "user":1, "at":"2020-11-24T23:06:20.0838188+03:30", "sources":{ "hn":"localhost:44398", "mn":"DESKTOP-N1GAV2U", "rip":"::1", "lip":"::1", "ua":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.198 Safari/537.36", "an":"Server.Api", "av":"1.0.0.0" }, "newValues":{ "Name":"Edited Farshad" } }, { "type":"Delete", "user":null, "at":"2020-11-24T23:06:28.601837+03:30", "sources":{ "hn":"localhost:44398", "mn":"DESKTOP-N1GAV2U", "rip":"::1", "lip":"::1", "ua":"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/86.0.4240.198 Safari/537.36", "an":"Server.Api", "av":"1.0.0.0" }, "newValues":null } ]
ولی روش گفته شده در این مقاله، همین عملیات را به صورت کاملتری و فقط بر روی یک ستون همان جدول انجام میدهد که باعث ذخیرهی دیتای کمتر، یکپارچگی بهتر و دسترسیپذیری و راحتی استفاده از آن میشود.