"C#" Posts

Two Level Multi-Tenancy Part 2

This is part two of my series on Two Level Multi-Tenancy. You’ll probably want to read part one first.

Last time, we looked at how to use the subdomain as part of our multi-tenant MVC application and how to bring that together. Now, we’re going to look at adding the secondary layer.

For this project, we ended up with three base model classes. A base model that adds Id and DateAdded, a First Level base model that has the Level1Id, and now our Second Level base model that add an Id field for Level2 models.

Each of our EF models then inherit from the Level2 base model with the exception of that model class that inherits from the Level1 model. And so all models inherit from the Level1 base model, which will cause all of them to have our Level1 Id field.

Our routes at this point look like subdomain.domain.com/Level2/Thing/Create. The project has a helper method that pulls the Level2 value from the route.

I also added another base controller, which again inherits from our Level1 base controller we set up in part 1.

public class Level2BaseController : Level1BaseController
    protected string Level2Name => GetFromRoute();

    protected override void OnActionExecuting(ActionExecutingContext filterContext)
        if (string.IsNullOrEmpty(Level2Name))
            filterContext.Result = RedirectToAction("Index", "Home");

        var identity = Thread.CurrentPrincipal.Identity as ClaimsIdentity;
        if (!identity.IsAuthenticated) return;
        var claim = identity.Claims.FirstOrDefault(c => c.Type == CustomClaims.Level2Id);
        if (claim == null || (claim.Value != Sessions.Level2Id.ToString())) Users.AddL2Claim(Level2Name);

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Two Level Multi-Tenancy Part 1

Recently, I’ve been working on a multi-tenancy project. Like most projects I tend to gravitate towards, it wasn’t that simple.

For those of you who know don’t know what that means, multi-tenancy is when an application is designed to be used by multiple companies/users at the same time, keeping all data separated from each other.

Typically if you want something like this done, you add a ClientId or some other restriction to your Models to help identify which tenant that Thing belongs to.

In the world of Entity Framework, you’d probably do Thing.Where(x => x.ClientId == clientId). You’d do this for each select statement, each update, and each delete to verify that the client that was logged in had the correct permissions to that resource. That’s boring, annoying, tedious and prone to errors.

Enter stage left comes Entity Framework interceptors. EF interceptors do what you’d expect them to do and intercept your EF queries before they hit the SQL server. Because they do this, it is possible to manipulate or log those queries.

Following some code by Charalampos Karypidis, I was able to get the basics setup. Because the rest of this article is an expansion of Charalampos’ code, I’ll not be reposting parts of his code that I didn’t change. You’ll want to go read and understand his article (or get the code on GitHub) before continuing. 

Where I part from Charalampos’ code is where I think things get interesting. Charalampos’ setup involves using the interceptor to assign TenantId to the UserId. That’s all fine and well, but what if there is actually a group of individuals all utilizing the same Tenant?

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ActionMailer for MVC 5.3

I've used ActionMailer.Net by Scott Anderson for a long time. That is, until he stopped supporting it. Fortunately, Crossvertise decided to pick up the torch and carry it a while longer. Crossvertise’s repo of ActionMailerNext has made some improvements over the years and has provided Mandrill and Sendgrid api support.

For those unfamiliar with it, ActionMailer is a .Net mailer library that allows the use of Razor views to send templated emails. You can pass models and view data into a View to fully script your transactional emails. Crossvertise’s supports both HTML and plain text variants and will automatically send one or both.

Unfortunately, the latest version ActionMailerNext.Mvc5-2 NuGet package includes dependencies on a Mandrill package and a Sendgrid package. It also is targeted at MVC 5.2 instead of 5.3.

I was recently challenged that if you don’t like something in Open Source…. FIX IT! 

So I did. 

As of this writing, my PR is still pending but as I wanted to use it in a timelier fashion, I’ve published the NuGet package myself. If Crossvertise elects to merge my PR, they are welcome to ownership of the package, however until such time: enjoy.


PM> Install-Package ActionMailerNext.Mvc5-3

Magical one page telerik reporting viewer

In an effort to simplify a project that used Telerik’s Reporting Engine, I wanted to create a single View that listed the available reports and a single View to hold the HTML Report Viewer. In the middle of the project a new requirement was added; you know how that goes. Some reports needed to be able to have querystring parameters come from a related View. This is how I did it. Behold the magic.


First I built my View to list the reports. Each report had a link like this:


@Html.ActionLink("Click Me", "Report", 
    new { title = "Report Title", path = "Namespace.Path.To.Report" }, 
    new { target = "_blank", @class = "btn btn-primary" })


You can get the Namespace path from the code behind file of the report.


Set up an ActionResult like this:


public ActionResult Report(string path, string title)


    ViewBag.ReportPath = path + ", ProjectNS";

    ViewBag.Title = title;

    return View();



ProjectNS should be your root Namespace. 


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About Me

Hello, I’m Jonathan Peterson (aka Eonasdan)! I’m a web developer and CEO of Paladin Cloudware.

I have over 11 years of experience developing a wide array of web applications and websites. In my free time, I contribute to several open source projects.

As a die-hard developer, you’ll find me programming in my head on the rare occasions when I'm without an Internet connection.

Find me on:


telerik, MVC, Entity Framework, ReSharper, Tips And Tricks, less, grunt, C#, visual studio, code quality, NuGet, visual studio 2015