Decoupling Asp.Net Identity 2.0 from Entity Framework in MVC5: Part 1


Usually the Asp.Net Identity 2.0 framework is aptly suited for most simple applications. However in complex line of business applications there is often a need to extend this base framework to map to growing application needs and architecture.
Today we are going to take a spin around the Asp.Net Identity 2.0 and see how we can de-couple it from the Entity framework and extend it further.

The implementation of the ApplicationDbContext that comes as a part of the standard template when we add Asp.Net Identity 2.0 to a MVC5 application is something like:

public class ApplicationUser : IdentityUser
{
    public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<ApplicationUser> manager) {
        var userIdentity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);
        return userIdentity;
    }
}

public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
    public ApplicationDbContext()
        : base("DefaultConnection", throwIfV1Schema: false) {
    }

    static ApplicationDbContext() {
        Database.SetInitializer<ApplicationDbContext>(new ApplicationDbInitializer());
    }

    public static ApplicationDbContext Create() {
        return new ApplicationDbContext();
    }
}

The IdentityDbContext does inherit from DbContext and in additions takes care of the Asp.Net Identity entities and related entities.

We will cover the entire post in 3 parts

Part 1

  • Implement the IdentityUser, IdentityRole and IdentityUserRole classes to support role based configuration for Asp.Net Identity framework
  • Make the ApplicationDbContext work with DbContext instead of IdentityDbContext<TUser> class
Part 2
  • Implement the UserStore without Claims and External Logins support to work with the new IdentityUser class
  • Implement RoleStore to work with the new IdentityRole class

Part 3

  • Implement Custom UserManager class to work with our new UserStore and IdentityUser entity
  • Implement Custom RoleManager class to work with our new RoleStore and IdentiyRole entity
  • A sample MVC5¬†application working with our custom system implementing basic user authentication and registration process using Asp.Net Identity

IdentityUser and Configuration class

public class IdentityUser: IUser
{
    #region Constructors

    public IdentityUser()
    {
        this.Id = Guid.NewGuid().ToString();
        this.Roles = (ICollection<IdentityUserRole>)new List<IdentityUserRole>();
    }

    public IdentityUser(string username): this()
    {
        this.UserName = username;
    }

    #endregion

    #region IUser<string> Members

    public string Id { get; set; }

    [Index("UserNameIndex", IsUnique=true)]
    public virtual string UserName { get; set; }

    public virtual string PasswordHash { get; set; }

    public virtual string SecurityStamp { get; set; }

    public virtual string Email { get; set; }

    public virtual int AccessFailedCount { get; set; }

    public virtual bool EmailConfirmed { get; set; }

    public virtual ICollection<IdentityUserRole> Roles { get; set; }

    #endregion

    #region Methods

    public async Task<ClaimsIdentity> GenerateUserIdentityAsync(UserManager<IdentityUser> manager)
    {
        var identity = await manager.CreateIdentityAsync(this, DefaultAuthenticationTypes.ApplicationCookie);
        return identity;
    }

    #endregion
}

public class IdentityUserConfiguration: EntityTypeConfiguration<IdentityUser>
{
    public IdentityUserConfiguration()
    {
        HasKey(t => t.Id);
        Property(t => t.Id).HasMaxLength(128);
        Property(t => t.UserName).IsRequired().HasMaxLength(256);
        Property(t => t.PasswordHash).IsRequired();
        Property(t => t.SecurityStamp).IsRequired();
        Property(t => t.Email).IsRequired().HasMaxLength(256);
        Property(t => t.EmailConfirmed).IsRequired();

        HasMany(t => t.Roles)
            .WithRequired(t => t.User)
            .HasForeignKey(t => t.UserId);

        ToTable("AspNetUsers");
    }
}

IdentityRole and configuration class

public class IdentityRole: IRole
{
    #region Constructors

    public IdentityRole()
    {
        this.Id = Guid.NewGuid().ToString();
    }

    public IdentityRole(string roleName): this()
    {
        this.Name = roleName;
    }

    public IdentityRole(string roleName, string id)
    {
        this.Name = roleName;
        this.Id = id;
    }

    #endregion

    #region IRole<string> Members

    public string Id { get; set; }

    [Index("RoleNameIndex", IsUnique=true)]
    public virtual string Name { get; set; }

    #endregion
}

public class IdentityRoleConfiguration: EntityTypeConfiguration<IdentityRole>
{
    public IdentityRoleConfiguration()
    {
        HasKey(t => t.Id);
        Property(t => t.Id).HasMaxLength(128);
        Property(t => t.Name).IsRequired().HasMaxLength(256);

        ToTable("AspNetRoles");
    }
}

IdentityUserRole and Configuration class

public class IdentityUserRole
{
    #region Properties

    public string UserId { get; set; }
    public virtual IdentityUser User { get; set; }

    public string RoleId { get; set; }
    public virtual IdentityRole Role { get; set; }

    #endregion

    #region Constructors

    public IdentityUserRole()
    {
    }

    public IdentityUserRole(string userId, string roleId)
    {
        this.UserId = userId;
        this.RoleId = roleId;
    }

    #endregion
}

public class IdentityUserRoleConfiguration: EntityTypeConfiguration<IdentityUserRole>
{
    public IdentityUserRoleConfiguration()
    {
        HasKey(t => new
        {
            t.RoleId,
            t.UserId
        });

        Property(t => t.UserId).HasColumnName("UserId");
        Property(t => t.RoleId).HasColumnName("RoleId");

        ToTable("AspNetUserRoles");
    }
}

And our new ApplicationDbContext class now becomes

public class ApplicationDbContext: DbContext
{
    static ApplicationDbContext()
    {
        Database.SetInitializer<ApplicationDbContext>(null);
    }

    public ApplicationDbContext()
        : base("DefaultConnection")
    {
        this.Configuration.ValidateOnSaveEnabled = true;
        this.Configuration.AutoDetectChangesEnabled = true;
    }

    public new IDbSet<T> Set<T>() where T : class
    {
        return base.Set<T>();
    }

    protected override void OnModelCreating(DbModelBuilder modelBuilder)
    {
        modelBuilder.Configurations.AddFromAssembly(typeof(IdentityModel.Configurations.IdentityUserConfiguration).Assembly);
    }
}

In the next part we will look at the implementations of:

  • UserStore
  • RoleStore

Simple jquery function to set active navigation link with Twitter Bootstrap


Usually in a web application you would want the user to know which link is active by highlighting the active link. Twitter Bootstrap has a class

.active

that we can use to do this. This class needs to be applied to an

<li> <a href="#"></a> </li>

tag.

Html Structure

<ul class="nav">
    <li>
        <a href="/Home/Index">Index</a>
    </li>
    <li>
        <a href="/Home/About">About</a>
    </li>
</ul>

Jquery function

$(document).ready(function () {
    $('.nav a').each(function () {
        var url = $(this).attr('href');
        if (currentlocation == url) {
            $(this).closest('li').addClass(&quot;active&quot;);
        }
    });
});

And that’s it! Of course there are a lot many other approaches as well that we can use. This is just a most simplistic to get something up and running in a simple project.

C# dynamic and ExpandoObject to fetch data from Sql Server


A little while ago I was working on a simple application that would let the user define or upload an HTML template and then upload the data that would map to the template. The data could be csv or an excel file. The user could define multiple HTML templates and correspondingly upload data files for each template. The HTML templates and the data files were to be stored in the application for anytime use.

Obviously I had to figure out a mechanism to read the Excel sheet’s columns and corresponding data and get that into an SQL table. That was simple enough. Using the LinqToExcel library ¬†I could read the excel data as simply as:


var excelFactory = new ExcelQueryFactory(fileName);                
var worksheet = excelFactory.GetWorksheetNames();
var columnNames = excelFactory.GetColumnNames(worksheet.FirstOrDefault());
                
var data = (from row in excelFactory.Worksheet(0)
            select row).ToList();

And then just simply store that list into the database.
But the issue was when I was reading that data back from the SQL database, I didn’t have any POCO classes to map that data to for my application to understand. So, this is what ended up doing in the end:

A simple function to read data from the database provided the table name

public IEnumerable<dynamic> GetData(string tableName)
{
    using (var connection = new SqlConnection(this.GetConnectionString()))
    {
        var commandText = "select * from " + tableName;
        using (var command = new SqlCommand(commandText, connection))
        {
            connection.Open();
            using (var reader = command.ExecuteReader())
            {
                while (reader.Read())
                {
                    yield return GetDynamicData(reader);
                }
            }
            connection.Close();
        }
    }
}

private dynamic GetDynamicData(SqlDataReader reader)
{
    var expandoObject = new ExpandoObject() as IDictionary<string, object>;
    for (int i = 0; i < reader.FieldCount; i++)
    {
        expandoObject.Add(reader.GetName(i), reader[i]);
    }
    return expandoObject;
}

And then just cast each item in the returned

IEnumerable<dynamic>

to an

IDictionary<string, object>

and bind that to my view or do any processing with it.