Note : .Net 6 / C# Adding timestamp and user created modified to when saving data

As a Laravel user for quite sometime, it's quite easy for me to add User creator, modifier and timestamp for each model.

In the case of .Net 6 (or even earlier) it can be handled at DbContext and creating your base class that has the generic properties for the timestamps (created at, modified at) and user details (created_by / modified_by) 

using System.ComponentModel.DataAnnotations;

namespace YourApp.Models{

    public class BaseEntity

    {

        public DateTime DateCreated { get; set; }

        [Required]

        //id of the user created

        public string UserCreated { get; set; }

        public DateTime? DateModified { get; set; }

        [Required]

        //id of the user edited

        public string UserModified { get; set; }

    }

}

Below is my subclass using the super class BaseEntity

using System.ComponentModel.DataAnnotations;

using System.ComponentModel.DataAnnotations.Schema;

namespace YourApp.Models;

/*

 * Patient Model 

 */

public class MyCustomModel : BaseEntity

{

    [StringLength(125)]

    public string FirstName { get; set; }

    [StringLength(125)]

    public string LastName { get; set; }

    [StringLength(125)]

    public string Middlename { get; set; } = string.Empty;

}

So how to automatically do the timestamps and user details? I implemented the tutorial from the blog that I followed here. According to the blog, you can implement it at the override of your DbContext'  SaveChangesAsync.

My DbContext below. I highlighted from the code below the important parts where the magic happens.

using Microsoft.EntityFrameworkCore;

using YourApp.Models;

using System.Security.Claims;

namespace YourApp.Contexts

{

    public class DataContext : DbContext

{

private readonly IHttpContextAccessor _httpContextAccessor;

public DataContext(DbContextOptions <DataContext> options, IHttpContextAccessor httpContextAccessor) : base(options) 

{

_httpContextAccessor = httpContextAccessor;

}

        public DbSet<MyCustomModel > CustomModels{ get; set; }

        protected override void OnModelCreating(ModelBuilder builder)

        {

          base.OnModelCreating(builder);

        }

public override Task<int> SaveChangesAsync(CancellationToken cancellationToken = default)

{

var insertedEntries = this.ChangeTracker.Entries()

.Where(x => x.State == EntityState.Added)

.Select(x => x.Entity);

var userId = _httpContextAccessor.HttpContext.User.FindFirst(ClaimTypes.NameIdentifier).Value;

var currentUsername = !string.IsNullOrEmpty(userId)

? userId

: "Anonymous";

foreach (var insertedEntry in insertedEntries)

{

var auditableEntity = insertedEntry as BaseEntity;

//If the inserted object is an Auditable. 

if (auditableEntity != null)

{

auditableEntity.DateCreated = DateTime.Now;

auditableEntity.UserCreated = currentUsername;

auditableEntity.UserModified = currentUsername;

}

}

var modifiedEntries = this.ChangeTracker.Entries()

.Where(x => x.State == EntityState.Modified)

.Select(x => x.Entity);

foreach (var modifiedEntry in modifiedEntries)

{

//If the inserted object is an Auditable. 

var auditableEntity = modifiedEntry as BaseEntity;

if (auditableEntity != null)

{

auditableEntity.DateModified = DateTime.Now;

auditableEntity.UserModified = currentUsername;

}

}

return base.SaveChangesAsync(cancellationToken);

}

}

}

Aside from that, ensure also from your login that ClaimTypes.NameIdentifier is not empty

var userId = _httpContextAccessor.HttpContext.User.FindFirst(ClaimTypes.NameIdentifier).Value;

I set my value during login. See login method below.

    [HttpPost]

    [Route("login")]

    public async Task<IActionResult> Login([FromBody] UserLogin model)

    {

      var user = await _userManager.FindByNameAsync(model.Username);

      if (user != null && await _userManager.CheckPasswordAsync(user, model.Password))

      {

        var userRoles = await _userManager.GetRolesAsync(user);

        var authClaims = new List<Claim>

                {

                    new Claim(ClaimTypes.Name, user.UserName),

                    new Claim(ClaimTypes.NameIdentifier, user.Id),

                    new Claim(JwtRegisteredClaimNames.Jti, Guid.NewGuid().ToString()),

                };

        foreach (var userRole in userRoles)

        {

          authClaims.Add(new Claim(ClaimTypes.Role, userRole));

        }

        var token = GetToken(authClaims);

        return Ok(new

        {

          token = new JwtSecurityTokenHandler().WriteToken(token),

          expiration = token.ValidTo

        });

      }

      return Unauthorized();

    }

That pretty much of it. Hope that helps you too.