Browsing posts in: 5

The Subtle Perils of Controller Dependency Injection in ASP.NET Core MVC

Some time ago I wrote a blog about how ASP.NET MVC 6 discovers controllers. While a lot has change since then, including the name – now the framework being called ASP.NET Core MVC, the post is still valid and the processes described there haven’t really changed.

That said, there is one extra thing that should be added to it, and that is how external dependency injection containers relate to the process of controller discovery and instantiation, as there is a subtle difference between ASP.NET Core MVC and the “classic” frameworks – MVC 5 or Web API 2. This post is really sparked by the conversation on Twitter with Jeremy and Kristian.

Continue Reading

Re-using external view components in ASP.NET 5 & ASP.NET MVC 6

The other day we explored using view components in ASP.NET 5 – as a very nifty replacement for the old MVC ChildActions. View components allow you to package a piece of functionality into a reusable class, along with an accompanying view, that can be invoke from any other view on demand.

Today let’s take this a step further – and let’s see how you can configure ASP.NET MVC 6, to be able to consume view components not just from the current web project but from external sources – external assemblies too. This way you will be able to share and distribute your view components across multiple projects. This is definitely useful for anyone who has – for example – ever worked on a portal-style applications, where building reusable components is one of the most important development activities.

Continue Reading

Running ASP.NET 5 website on IIS

As ASP.NET 5 hit RC1 about a month go, more and more folks are looking at production deployments and other real life use cases of it. Going beyond demoware and experiments, to real applications, inevitably leads to thinking about hosting it somewhere – which, if your environment is Windows, most likely means IIS.

I have recently gone through quite some trouble getting it all to work, so I thought it might be useful to document and highlight some of the steps, which hopefully will save a bit of your time.

Continue Reading

Localized routes with ASP.NET 5 and MVC 6

In my Web API book, in one of the chapters (source here), I’m discussing an in interesting approach towards route localization, using attribute routing.

The whole idea came from the fact that at some point in the past I used to work on a really large application – 70+ language versions, all of which required localizations on the route level.

That approach allowed you to define a single attribute route at action level (as opposed to, well, 70+ routes), and have it auto-translated by the plugged in infrastructure, as long as you provide the mapping to other languages at application startup.

Let’s have a look at how same type of functionality can be built in ASP.NET MVC 6.

Continue Reading

Running a C# REPL in a DNX application with scriptcs

One of the cool things that scriptcs allows you to do, is that you can embed it into your application and allow execution of C# scripts. There are even some great resources on that out there, like this awesome post by Mads.

The same applies to the REPL functionality – you don’t have to use scriptcs.exe to access the REPL – you can use the scriptcs Nuget packages to create a REPL inside your app.

And because there aren’t that many resources (if any) on how to host a scriptcs REPL, today I wanted to show you just that. But for a more interesting twist, we’ll do that inside a DNX application.

There are many reasons why DNX is awesome, and why you’d want to use it, but especially because, through the project.json project system, it has a much improved way of referencing and loading dependencies and Nuget packages – and we can leverage that mechanism to feed assemblies into our REPL.

Continue Reading

ViewComponents in ASP.NET 5 and ASP.NET MVC 6

Let’s have a quick look at another new feature in ASP.NET MVC 6, and that is the ViewComponent feature. View components are intended to be replacements to ChildActions and, to some extent, of partial views.

Traditionally in ASP.NET MVC (and in general in the textbook MVC pattern), you had to compose the entire model in the controller and pass it along to the view, which simply rendered the entire page based on the data from the model. The consequence of this is that the view does not need to explicitly ask for any data – as its sole purpose is to just act upon the model it received.

While this sounds very nice in theory, it has traditionally posed a number of practical difficulties. There are a number of reusable components on pretty much every website – think a menu, a shopping cart, lists of all kinds, breadcrumbs, metadata and so on – so things that appear on multiple pages.

Let’s have a look at how this is solved in MVC 6.

Continue Reading

Migrating from Web API 2 to MVC 6 at NDC Oslo

Screenshot 2015-07-09 11.59.00Last month I gave a talk about migrating from Web API to MVC 6 and ASP.NET 5 at NDC Oslo.

Below you can find the the video, code and slides from the session.

Thanks for all who attended, I had a great time in Oslo! Hopefully we get to revisit this session soon too, when ASP.NET 5 becomes a bit more mature.


You can watch the talk on Vimeo.
And if you are wondering, yes I’m wearing a Bayern Munich jersey on stage :)


All the code is hosted at Gtihub. It contains the Web API 2 project, the MVC 6 “before” and the MVC 6 “after” version. It’s built using beta6 nightlies so you’ll need to install those to run the code.


Just go to this URL. Slides are also contained in the Github repository – powered by the almighty FsReveal.
Mind you this talk is all about code so there aren’t many slides anyway.

Action filters, service filters and type filters in ASP.NET 5 and MVC 6

Today, let's have a look at he area of filters in ASP.NET MVC 6 – because it actually contains quite a few interesting changes compared to classic MVC and Web API filter pipelines.

Let's leave the specialized filters (error filters, authorization filters) on a side for now, and focus instead on the functional, aspect oriented, filters. Aside from the good old action filters, known from both MVC and from Web API, there are two new types of filters (or rather filter factories, but we’ll get there) that you can use – ServiceFilters and TypeFilters.

Continue Reading

Integration testing ASP.NET 5 and ASP.NET MVC 6 applications

The other day I ran into a post by Alex Zeitler, who blogged about integration testing of ASP.NET MVC 6 controllers. Alex has done some great work for the Web API community in the past and I always enjoy his posts.

In this case, Alex suggested using self hosting for that, so spinning up a server and hitting it over HTTP and then shutting down, as part of each test case. Some people have done that in the past with Web API too, but is not an approach I agree with when doing integration testing. If you follow this blog you might have seen my post about testing OWIN apps and Web API apps in memory already.

My main issue with the self-host approach, is that you and up testing the underlying operating system networking stack, the so-called “wire” which is not necessarily something you want to test – given that it will be different anyway in production (especially if you intend to run on IIS). On the other hand, you want to be able to run end-to-end tests quickly anywhere – developer’s machine, integration server or any other place that it might be necessary, and doing it entirely in memory is a great approach.

Continue Reading