Shopping cart with SignalR, ASP.NET Web API and Knockout.js

net asp.net web api c-sharp knockout.js signalr
I have published an article at Tech.pro today, about building a real-time shopping cart with some of our favorite technologies - ASP.NET Web API, SignalR and Knockout.js (or, as Brad would say, with the “Webstack of Love”). Click here to head over there and read the article!

Leveraging Roslyn to author ASP.NET Web API without recompiling

net asp.net web api c-sharp roslyn

Some time ago I posted a mini-series of posts about using Roslyn to script Web API, and that has gotten some great response. In that original post, I mentioned & used, without going into too much details, a very useful “compiler as a service” feature Roslyn offers.

Recently, Glenn Block started a very exciting project called scriptcs (which now Justin Rusbtach and I happen to be a part of too) to provide a seamless/node.js-esque scripting experience for C# and in that project we indeed leverage on Roslyn heavily - to do some behind the scenes tricks to hide the compilation aspect from the user, so that it really resembles pure script execution.

Adding HTTP HEAD support to ASP.NET Web API

net asp.net web api c-sharp

HEAD HTTP verb is defined in RFC 2616 as “identical to GET except that the server MUST NOT return a message-body in the response.” As such you can think of it as a twin brother of GET.

There are a lot of use cases for HEAD: pinging without the overhead of transferring data, or simply requesting information about the size of a resource (which can be used to provide download progress bar), just to name a few.

Unfortunately, out of the box, ASP.NET Web API doesn’t provide a mechanism of supporting HEAD or coupling GET & HEAD.

We can work around that.

SignalR, Filters and ServiceStack

servicestack signalr
I recently blogged about a technique of integrating SignalR with ASP.NET Web API through the use of action filters. A few people have asked, whether this approach (and SignalR now being part of Microsoft’s ASP.NET product group after all) works with other frameworks. And the answer is absolutely yes. Let’s have a look at implementing this for ServiceStack. Adding ServiceStack 🔗You should probably have a look at the original article first, since the SignalR part of it will be identical.

ASP.NET Web API and Protocol Buffers

net asp.net web api c-sharp

Protocol Buffers are a super efficient and very flexible way of serializing structured data. Developed at Google, provide the developers lightspeed serialization and deserialization capabilities.

There a handful of .NET implementations, the most popular one, called protobuf-net, created by Marc Gravell from StackExchange. On top of that library, WebApiContrib project has a Web API Protocol Buffers formatter ready for you to plug in.

More after the jump.

SignalR, ActionFilters and ASP.NET Web API

net asp.net web api c-sharp signalr

There have been quite a few examples circulating on the web on how one would use SignalR together with Web API. It all started after Brad Wilson had a great example on calling SignalR from API controllers at NDC Oslo 2012.

Even on this blog we looked at calling SignalR from Web API ITraceWriter to provide realtime tracing capabilities.

How about, to avoid any controller-level noise, messaging the connected SignalR subscribers from ActionFilters? While this approach might not be applicable in all scenarios, when it is, I think it could provide a nice layer of separation.

More after the jump.

But I don’t want to call Web Api controllers “Controller”!

net asp.net web api c-sharp

A friend of mine was recently complaining about how Web API controller centric approach doesn’t really make sense, and that he prefers feature-oriented endpoints. While - in all honesty - I am not sure what he means by that, it got me thinking. Maybe, if we didn’t have to suffix Web API controllers “Controller”, that would make him happy?

More after the jump.

Building Web API Visual Studio support tools with Roslyn

net asp.net web api c-sharp roslyn

In my humble opinion, Microsoft Roslyn is one of the most exciting things on the .NET stack. One of the many (MANY) things you can do easily with Roslyn, is write your own development-time code analysis tools.

We have talked about Roslyn scripting capabilities on this blog before (twice actually). Let’s look at code analysis today and see how we could built tools that could help Web API developers build nice clean HTTP services.

More after the jump.

Building real time applications for any client with Azure Mobile Services & Pusher

azure javascript last.fm api

Azure Mobile Services is definitely one of the coolest technologies in the Azure family. One of the issues however, has been that it only has client libraries for Windows 8, iOS and Android, making it a bit more difficult for developers targeting other platforms (also web browsers!) to take advantage of its capabilities.

A while ago, I blogged about how to work around that - by using ZUMO REST API. However, you still didn’t have access to one of the nicest features of ZUMO for mobile devices - and that is push notifications. That changed recently, when ZUMO announced a partnership with Pusher, to provide push notifications for virtually any client.

Additionally, the team recently released another cool feature - scheduled tasks (cron jobs). Let’s see how you can use it all together to quickly build a realtime service.

More after the jump.

Adding Request.IsLocal to ASP.NET Web API

net asp.net web api c-sharp

I was recently asked how to filter out local requests in Web API. Indeed, one of the more useful things that developers got used to work with in traditional ASP.NET (and the System.Web.dll) was the ability to quickly check if a given request is a local one or not - by simply calling the IsLocal boolean property on HttpRequest.

This has been omitted from HttpRequestMessage in the new HTTP object model, around which Web API is built, but Web API still keeps track of that information under the hood, so you can easily write a simple extension method to bring back the old familiar syntax.

More after the jump.

About

Hi! I'm Filip W., a software architect from Zürich 🇨🇭. I like Toronto Maple Leafs 🇨🇦, Rancid and quantum computing. Oh, and I love the Lowlands 🏴󠁧󠁢󠁳󠁣󠁴󠁿.

You can find me on Github, on Mastodon and on Bluesky.

My Introduction to Quantum Computing with Q# and QDK book
Microsoft MVP

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