c# - Moving ASP.NET Identity model to class library

Question

I am trying to move the Identity model to a class library using the methods in this link:

ASP.NET Identity in Services library

Problem 1: It seems to keep using the Website project's connection string. I overcame it by specifying the full connection string in the class library. Can I make the IdentityDbContext use the class library's connection string?

Problem 2: Due to the problem 1, if I remove the Entity Framework from the website project. It will give the following error that it is looking for EF's SqlClient in the Website project.

An exception of type 'System.InvalidOperationException' occurred in EntityFramework.dll but was not handled in user code

Additional information: No Entity Framework provider found for the ADO.NET provider with invariant name 'System.Data.SqlClient'. Make sure the provider is registered in the 'entityFramework' section of the application config file. See http://go.microsoft.com/fwlink/?LinkId=260882 for more information.

Other solutions are welcome as long as it omits all Data Access Layer references like EF in the Website project.

Answer 1

To move the IdentityModel into a class library (which is the right thing to do according to the SRP), follow these steps:

1. Create a class library. (ClassLibrary1)
2. Using NuGet, add a reference to Microsoft.AspNet.Identity.EntityFramework. This will also auto-add some other references.
3. Add a reference in your website to ClassLibrary1
4. Find WebSite/Models/IdentityModel.cs and move it to ClassLibrary1.

5. Make IdentityModel.cs look like this:

   public class ApplicationUser : IdentityUser
   {
   }
   
   public class ApplicationDbContext : IdentityDbContext<ApplicationUser>
   {
       public ApplicationDbContext()
           : base("YourContextName")
       {
       }
   }
   

6. Make sure your website's Web.config has YourContextName pointing to the right database in the section. (Note: this database can and should house your application data).

   <add name="YourContextName" connectionString="YourConnectionStringGoesHere"
     providerName="System.Data.SqlClient" />
   

7. Make your EF Context class inherit from your ApplicationDbContext:

   public class YourContextName : ApplicationDbContext
   {
       public DbSet<ABizClass1> BizClass1 { get; set; }
       public DbSet<ABizClass2> BizClass2 { get; set; }
       // And so forth ...
   }
   

When anyone in your site tries to log in or register, the Identity system will route them to your database with all your data which includes the Identity tables.

Good to go!