Note: This blog post relates to a library undergoing development and as such the information is likely to become outdated.

Even with Database First through the EDMX gone in Entity Framework 7 it's still possible to work with existing databases.

While trying this out with one of my databases I ran into the following Exception:

<Message>An error has occurred.</Message>

<ExceptionMessage>Invalid object name 'SomeClass'.</ExceptionMessage>

<ExceptionType>System.Data.SqlClient.SqlException</ExceptionType>

<StackTrace>
at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)[...]
</StackTrace>

The Entity Framework "Invalid object name [class name]" exception means that the matching table for one of your classes hasn't been found.

In this case I'm trying to map the SomeClass to the underlying SQL table Map.Test:

[Table("Test", Schema="Map")]
public class SomeClass
{
    public int Id { get; set; }
}

The current version of EF7 (7.0.0-rc1-11953) does not have support for mapping using attributes in this way. Instead one must use Fluent configuration in the DbContext as follows:

public class MyContext : DbContext
{
    public DbSet<SomeClass> SomeClasses { get; set; }

    protected override void OnConfiguring(DbContextOptions options)
    {
        options.UseSqlServer(ConnectionString);
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        base.OnModelCreating(modelBuilder);

        modelBuilder.Entity<SomeClass>().ForRelational().Table(tableName: "Test", schemaName: "Map");
    }
}

The mapping is configured fluently in the OnModelCreating method. For slightly more useful information about setting EF7 up see this link.

I hope this helps!

Fun fact for you dear reader, I've not been programming for long, my degree was in Chemistry and though I taught myself a little programming during my degree I was mainly focused on Chemistry. This means I've been programming professionally for less time than C# 5 has been released.

This is why I've found tutorials so far for the Async/Await features in C# 5 (Net 4.5) to be a little lacking, they generally assume the reader has been writing async programs prior to the release of the features.

As a solution to this I've endeavoured to write a guide to async for miserable slugs like myself who have not had exposure to async prior to these keywords.

Demo Scenario

We're going to stick with a very simple console app available on GitHub to make sure all the concepts can be understood by a slug.

Our Program.cs main method is shown below:

public static void Main(string[] args)
{   
    SlugService slugService = new SlugService();
    slugService.GetSlugs(generation: 1);
}

The GitHub version contains a lot more lines which allow the method calls to be timed with the built in stopwatch.

The Slug Service is tasked with retrieving the records of some slugs we've stored somewhere. Let's see what it does:

This post runs through how to create a form for creating a model with a list of child models using MVC 5 and Razor.

I've been rather quiet on the blogging front lately, I've been working on getting my MVC 5 quiz application up and running on Azure, it's here if anyone wants to give it a go.

One thing I wanted to do while working on the site was allow for a model to be created along with a list of "sub" models; for example when creating a question it would be nice for a user to also create the answers on the same page.

Setup

To demo this we need a model which could "own" some collection of other items. I happened on the perfect example today in the Json.NET source:

Given how much you all enjoyed the previous tutorial, i.e. not at all, I thought I'd write a follow up post. As promised this blog post extends the basic system we created in the main tutorial to add roles and a password reset function.

I won't show how to setup the emails for password reset because I'm too lazy to fill in the form for a free SendGrid account, however plugging emails in should be the easy bit.

Password Reset

The default template provides the controller actions and views for a full password reset function. The user can enter an email address at /Account/ForgotPassword. When posted the action below is called:

public async Task<ActionResult> ForgotPassword(ForgotPasswordViewModel model)
{
    if (ModelState.IsValid)
    {
        var user = await UserManager.FindByNameAsync(model.Email);
        if (user == null || !(await UserManager.IsEmailConfirmedAsync(user.Id.ToString())))
        {
            // Don't reveal that the user does not exist or is not confirmed
            return View("ForgotPasswordConfirmation");
        }
        string code = await UserManager.GeneratePasswordResetTokenAsync(user.Id.ToString());
        var callbackUrl = Url.Action("ResetPassword", "Account", new { userId = user.Id, code = code }, protocol: Request.Url.Scheme);      
        // await UserManager.SendEmailAsync(user.Id, "Reset Password", "Please reset your password by clicking <a href=\"" + callbackUrl + "\">here</a>");
        return RedirectToAction("ForgotPasswordConfirmation", "Account");
    }
    return View(model);
}

I have commented out the email sending part for the reasons mentioned above.

All we need to do is supply our UserManager with a token provider. From the code for the default UserManager:

/// <summary>
/// Used for generating reset password and confirmation tokens
/// </summary>
public IUserTokenProvider<TUser, TKey> UserTokenProvider { get; set; }

As usual Microsoft have made everything easy by giving us a nice interface to implement. This also means you can adapt your password reset to function however you like. For instance you could add an expiry date to the reset token or have a token which is a combination of a Guid and number or two Guids.

For my token provider I'm simply going to generate a new Guid to act as the reset token. This maps onto the nullable reset token field on my user table, I've hidden some stuff here because I don't want you stealing the super secure password hashes ("password" and "password1"):

Note: This is the second post in a 2 post tutorial on implementing Identity 2.0 without using EF, for post 1 go here.

Now we have our User and UserStore classes we can change the UserManager and SignInManager our application uses. These classes are in the App_Start/IdentityConfig.cs file.

I split the classes out to their own files, ApplicationUserManager.cs and ApplicationSignInManager.cs respectively. In their unmodified state these classes inherit from the classes provided by the Identity library.

ApplicationUserManager

The manager provides many methods to use in our controllers, a few examples are:

public virtual Task<IdentityResult> ResetAccessFailedCountAsync(TKey userId);
public virtual Task<IdentityResult> ResetPasswordAsync(TKey userId, string token, string newPassword);
public virtual Task SendEmailAsync(TKey userId, string subject, string body);

The manager mainly delegates to classes it owns such as the user store to run these methods. The default template UserManager is shown below:

public class ApplicationUserManager : UserManager<ApplicationUser>
{
    public ApplicationUserManager(IUserStore<ApplicationUser> store)
        : base(store) { }

    public static ApplicationUserManager Create(IdentityFactoryOptions<ApplicationUserManager> options, 
        IOwinContext context) 
    {
        var manager = new ApplicationUserManager(
            new UserStore<ApplicationUser>(context.Get<ApplicationDbContext>()));

        // Configure validation logic for usernames
        manager.UserValidator = new UserValidator<ApplicationUser>(manager)
        {
            AllowOnlyAlphanumericUserNames = false,
            RequireUniqueEmail = true
        };

        // Configure validation logic for passwords
        manager.PasswordValidator = new PasswordValidator
        {
            RequiredLength = 6,
            RequireNonLetterOrDigit = true,
            RequireDigit = true,
            RequireLowercase = true,
            RequireUppercase = true,
        };

        [CONTENT REMOVED TO SAVE SPACE...]
        return manager;
    }
}

Because everything takes arguments based on interfaces we've already created our classes for, the rewrite is very simple. Firstly we replace all instances of ApplicationUser with our class which implements IUser, in our case MyUser:

public class ApplicationUserManager : UserManager<MyUser>
{
    public ApplicationUserManager(IUserStore<MyUser> store)
        : base(store)
    {
        this.UserValidator = new MyUserValidator<MyUser, string>();
    }

    public static ApplicationUserManager Create(IdentityFactoryOptions<ApplicationUserManager> options, 
        IOwinContext context)
    {
        var manager = new ApplicationUserManager(new MyUserStore<MyUser>());
        // Configure validation logic for usernames
        manager.UserValidator = new UserValidator<MyUser>(manager)
        {
            AllowOnlyAlphanumericUserNames = false,
            RequireUniqueEmail = true
        };

        // Configure validation logic for passwords
        manager.PasswordValidator = new PasswordValidator
        {
            RequiredLength = 3,
            RequireNonLetterOrDigit = false,
            RequireDigit = false,
            RequireLowercase = true,
            RequireUppercase = false
        };

        // Configure user lockout defaults
        manager.UserLockoutEnabledByDefault = false;

        manager.EmailService = new EmailService();
        manager.SmsService = new SmsService();

        return manager;
    }
}

I set the password requirements to be super weak for manual testing because typing secure passwords repeatedly was too much like hard work!

We also remove the default UserStore which depends on Entity Framework and insert our own MyUserStore (which in this tutorial also depends on EF but with no requirement to pass a DbContext to the constructor). Additionally all parts setting up 2 Factor Auth are removed.