Activity logs through Telerik Data Access

Some time back I had written a blog on managing history for required models (http://vikutech.blogspot.in/2015/08/implementing-automating-audit-logs-in-telerik-data-access.html). In this particular example, we would be looking for managing small summary of information based on tables affected in the particular request of context. Like what kind of operation were done on models and by whom.

The approach for implementation is to create required model to store summary information and attach DB context events based on required format.

The Basic data model for collecting information, just having user identifier and message.

   /// <summary>  
   /// User activity log domain model  
   /// </summary>  
   public class UserActivityLog  
   : IPrimaryKey<int>  
   {  
     /// <summary>  
     /// Gets or sets the identifier.  
     /// </summary>  
     /// <value>The identifier.</value>  
     public int Id { get; set; }  
     /// <summary>  
     /// Gets or sets FkUserId  
     /// </summary>  
     public int FkUserId { get; set; }  
     /// <summary>  
     /// LogTime property's baking field.  
     /// </summary>  
     private DateTime logTime;  
     /// <summary>  
     /// Gets or sets LogMessage  
     /// </summary>  
     public string LogMessage { get; set; }  
     /// <summary>  
     /// Gets or sets LogTime  
     /// </summary>  
     public DateTime LogTime { get; set; }  
     /// <summary>  
     /// Gets or sets Security User  
     /// </summary>  
     public SecurityUser SecurityUser { get; set; } //Associated model  
   }  

The DTO to handle the little logic for combining and composing a full message. I have used Humanizer https://www.nuget.org/packages/Humanizer for formatting texts.

 /// <summary>  
   /// Database operation keys  
   /// </summary>  
   public enum DbOperation  
   {  
     /// <summary>  
     /// Insert operation  
     /// </summary>  
     Insert,  
     /// <summary>  
     /// Delete operation  
     /// </summary>  
     Delete,  
     /// <summary>  
     /// Update operation  
     /// </summary>  
     Update  
   }  
 /// <summary>  
   /// User activity logs  
   /// </summary>  
   public class ActivityLogs  
   {  
     /// <summary>  
     /// Initializes a new instance of the <see cref="ActivityLogs"/> class.  
     /// </summary>  
     /// <param name="userId">The user identifier.</param>  
     public ActivityLogs(int userId)  
     {  
       ActivityItems = new List<ActivityLog>();  
       UserId = userId;  
     }  
     /// <summary>  
     /// Gets the user identifier.  
     /// </summary>  
     /// <value>  
     /// The user identifier.  
     /// </value>  
     public int UserId { get; private set; }  
     /// <summary>  
     /// Gets or sets the activity items.  
     /// </summary>  
     /// <value>  
     /// The activity items.  
     /// </value>  
     private IList<ActivityLog> ActivityItems { get; set; }  
     /// <summary>  
     /// Gets a value indicating whether this instance has records.  
     /// </summary>  
     /// <value>  
     /// <c>true</c> if this instance has records; otherwise, <c>false</c>.  
     /// </value>  
     public bool HasRecords  
     {  
       get  
       {  
         return ActivityItems.Any();  
       }  
     }  
     /// <summary>  
     /// Adds the new activity log.  
     /// </summary>  
     /// <param name="model">The type model.</param>  
     /// <param name="operation">The DB operation done.</param>  
     public void Add(Type model, DbOperation operation)  
     {  
       var friendlyName = model.Name.Humanize(LetterCasing.Title);  
       var activityLog = ActivityItems.FirstOrDefault(log => log.ModelName == friendlyName);  
       if (activityLog == null)  
       {  
         activityLog = new ActivityLog(friendlyName);  
         ActivityItems.Add(activityLog);  
       }  
       SetCount(activityLog, operation);  
     }  
     /// <summary>  
     /// Clears the instance for saving new records.  
     /// </summary>  
     public void Clear()  
     {  
       ActivityItems = new List<ActivityLog>();  
     }  
     /// <summary>  
     /// String representation of instance.  
     /// </summary>  
     /// <returns>  
     /// A <see cref="System.String" /> that represents this instance.  
     /// </returns>  
     public override string ToString()  
     {  
       var msg = new StringBuilder();  
       Action<DbOperation, string, string> createMessage = (operation, startString, endString) =>  
       {  
         var items = GetItems(operation).ToList();  
         if (items.Any())  
         {  
           const string APPEND_FORMAT = "{0} {1}{2}";  
           msg.AppendFormat(APPEND_FORMAT, startString, items.Humanize(), endString);  
         }  
       };  
       createMessage(DbOperation.Insert, "Insert new records of", ".");  
       createMessage(DbOperation.Delete, "Delete", ".");  
       createMessage(DbOperation.Update, "Save details of", ".");  
       return msg.ToString();  
     }  
     /// <summary>  
     /// Gets the items based on DB Operation.  
     /// </summary>  
     /// <param name="operation">The operation.</param>  
     /// <returns>Activity logs based on DB operation.</returns>  
     private IEnumerable<ActivityLog> GetItems(DbOperation operation)  
     {  
       switch (operation)  
       {  
         case DbOperation.Insert:  
           return ActivityItems.Where(log => log.InsertCount > 0);  
         case DbOperation.Delete:  
           return ActivityItems.Where(log => log.DeleteCount > 0);  
         case DbOperation.Update:  
           return ActivityItems.Where(log => log.UpdateCount > 0);  
       }  
       return Enumerable.Empty<ActivityLog>();  
     }  
     /// <summary>  
     /// Sets the count as per DB operation of log instance.  
     /// </summary>  
     /// <param name="log">The log.</param>  
     /// <param name="operation">The DB operation.</param>  
     private void SetCount(ActivityLog log, DbOperation operation)  
     {  
       switch (operation)  
       {  
         case DbOperation.Insert:  
           log.InsertCount++;  
           break;  
         case DbOperation.Delete:  
           log.DeleteCount++;  
           break;  
         case DbOperation.Update:  
           log.UpdateCount++;  
           break;  
       }  
     }  
     /// <summary>  
     /// Activity log item  
     /// </summary>  
     private class ActivityLog  
     {  
       /// <summary>  
       /// Initializes a new instance of the <see cref="ActivityLog"/> class.  
       /// </summary>  
       /// <param name="modelName">Name of the model.</param>  
       public ActivityLog(string modelName)  
       {  
         ModelName = modelName;  
       }  
       /// <summary>  
       /// Gets or sets the name of the model.  
       /// </summary>  
       /// <value>  
       /// The name of the model.  
       /// </value>  
       public string ModelName { get; set; }  
       /// <summary>  
       /// Gets or sets the delete count.  
       /// </summary>  
       /// <value>  
       /// The delete count.  
       /// </value>  
       public int DeleteCount { get; set; }  
       /// <summary>  
       /// Gets or sets the insert count.  
       /// </summary>  
       /// <value>  
       /// The insert count.  
       /// </value>  
       public int InsertCount { get; set; }  
       /// <summary>  
       /// Gets or sets the update count.  
       /// </summary>  
       /// <value>  
       /// The update count.  
       /// </value>  
       public int UpdateCount { get; set; }  
       /// <summary>  
       /// Returns a <see cref="System.String" /> that represents this instance.  
       /// </summary>  
       /// <returns>  
       /// A <see cref="System.String" /> that represents this instance.  
       /// </returns>  
       public override string ToString()  
       {  
         return ModelName;  
       }  
     }  
   }  

To get user identity System.Security.Principal.IPrincipal can be passed to DB/Business layer to avoid any Web references.

   /// <summary>  
   /// OpenContext wrapper class for MyProject   
   /// </summary>  
   public sealed class MyProjectContext  
   : OpenAccessContext  
   {  
     /// <summary>  
     /// The user identifier  
     /// </summary>  
     private int? userId;  
     /// <summary>  
     /// Gets or sets the activity log track.  
     /// </summary>  
     /// <value>  
     /// The activity log track.  
     /// </value>  
     internal ActivityLogs ActivityLogTrack { get; set; }  
     /// <summary>  
     /// Gets or sets the user principal.  
     /// </summary>  
     /// <value>  
     /// The user principal.  
     /// </value>  
     internal IPrincipal UserPrincipal { get; set; }  
     /// <summary>  
     /// Gets the user identifier.  
     /// </summary>  
     /// <value>  
     /// The user identifier.  
     /// </value>  
     private int? UserId  
     {  
       get  
       {  
         if (UserPrincipal != null && !userId.HasValue)  
         {  
           var id = GetAll<SecurityUser>()  
                           .Where(usr => usr.UserName == UserPrincipal.Identity.Name)  
                           .Select(user => user.Id)  
                           .FirstOrDefault();  
           userId = id != 0 ? (int?)id : null;  
         }  
         return userId;  
       }  
     }  
     /// <summary>  
     /// Initializes a new instance of the <see cref="MyProjectContext" /> class.  
     /// </summary>  
     /// <param name="connectionStringName">Name of the connection string.</param>  
     /// <param name="backendName">Name of the back-end.</param>  
     /// <param name="userPrincipal">Object for user information.</param>  
     public MyProjectContext(string connectionStringName, string backendName, MyFluentMetadataSource metaSource, IPrincipal userPrincipal)  
       : base(ConnectionString = connectionStringName,  
       BackEndConfig = GetBackendConfiguration(backendName),  
       MetaSource = new MetaSource())  
     {  
       UserPrincipal = userPrincipal;
        Events.Removing += (sender, e) => AddActivityLog(DbOperation.Delete, e.PersistentObject);  
       Events.Added += (sender, e) => AddActivityLog(DbOperation.Insert, e.PersistentObject);  
       Events.Changed += (sender, e) => AddActivityLog(DbOperation.Update, e.PersistentObject);  
     }  
     /// <summary>  
     /// Gets the back-end configuration.  
     /// </summary>  
     /// <param name="backendName">Name of the back-end.</param>  
     /// <returns><see cref="BackendConfiguration"/> for context configuration.</returns>  
     public static BackendConfiguration GetBackendConfiguration(string backendName)  
     {  
       var backendConfiguration = new BackendConfiguration();  
       backendConfiguration.Backend = backendName;  
       backendConfiguration.ProviderName = "System.Data.SqlClient";  
       return backendConfiguration;  
     }  
     /// <summary>  
     /// Adds the activity log.  
     /// </summary>  
     /// <param name="opType">Type of the operation.</param>  
     /// <param name="persistentObject">The persistent object.</param>  
     private void AddActivityLog(DbOperation opType, Object persistentObject)  
     {  
                // TODO: Avoid any models  
       if (persistentObject as UserActivityLog != null ||  
         persistentObject as LogError != null)  
       {  
         return;  
       }  
       if (UserId.HasValue)  
       {  
         if (ActivityLogTrack == null)  
         {  
           ActivityLogTrack = new ActivityLogs(UserId.Value);  
         }  
         ActivityLogTrack.Add(persistentObject.GetType(), opType);  
       }  
     }  
   }  

The save method can be written under UnitOfWork Save method or any of other abstraction consuming context.
The below code is based on UnitOfWork approach http://vikutech.blogspot.in/2015/01/architecture-solution-composting-repository-pattern-unit-of-work-dependency-injection-factory-pattern.html

     /// <summary>  
     /// Saves Context changes.  
     /// </summary>  
     public override void Save()  
     {  
       var ctx = Context as MyProjectContext;  
       // Save activity log of user.  
       if (ctx != null && ctx.ActivityLogTrack != null)  
       {  
         var activityLogSummary = ctx.ActivityLogTrack;  
         if (activityLogSummary.HasRecords)  
         {  
           ctx.Add(new UserActivityLog  
               {  
                 LogMessage = activityLogSummary.ToString(),  
                 LogTime = DateTime.UtcNow, // Save as local date time  
                 FkUserId = activityLogSummary.UserId  
               });  
         }  
         ctx.ActivityLogTrack.Clear();  
       }  
       base.Save();  
     }  

This makes single entry into data model along with the formatted message for all the names of model names which have been updated/deleted/added.