Technology

Like WCF: Only Cleaner

I’ve been working with the Service Stack framework recently. Service Stack is a great SOA framework for building REST (and RPC) based web services – lots of the great things about WCF are in there – but they fixed lots of the problems. The thing that initially attracted me to it, is that it does what WCF does without all the XML configuration. I know projects whose XML file count has gone way up when they start using WCF. In one extreme case, a project that wanted a sustainable development environment with different configs for development, staging, production, and qa but also wanted separate files for endpoints, behaviours and services ended up with over 500 XML files in trunk. It takes a zen like state to manage all of this, and unfortunately it takes hours to reach that zen!

Want more on ServiceStack? ServiceStack 4 Cookbook contains over 70 recipes on building quality services and applications with ServiceStack!

Service stack could have just been “WCF without the mess” and I would have loved it, but they didn’t stop there – they focused on doing it better and faster. The benchmarks tell the story. Their JSON and XML serializers are 3 to 4 times faster than the Microsoft components in WCF! Add to that Service Stack is much more testable.

So, you might ask, what does the code look like? You can implement a very testable service in very little code. We’ll start out with a request object and object model like this:

Event

public class Event
{
    public string Subject { get; set; }
    public DateTime EventDate { get; set; }
    public string Speaker { get; set; }
    public DateTime EventStart { get; set; }
}

EventRequest

public class EventRequest
{
    public int? Page { get; set; }
    public string SearchTerm { get; set; }
}

Then we’ll start a test:

[TestMethod]
public void CanIDownloadAListOfEvents()
{
  var request = new EventRequest();
  var target = new EventsService();
  var actual = target.OnGet(request);
  Assert.IsNotNull(actual);
}

EventsService is red because we haven’t made one yet, so let’s add one of those:

EventService

public class EventsService : RestServiceBase<EventRequest>
{
  public override object OnGet(EventRequest request)
  {
    return new EventResponse();
  }
}

Here’s where Service Stack does some magic… To wire up a service on that Events request object, we just need to annotate it properly:

EventRequest

[DataContract]
[RestService("/events", "GET")]
[RestService("/events/page/{Page}", "GET")]
[RestService("/events/search/{SearchTerm}", "GET")]
public class EventRequest
{
    [DataMember]
    public int? Page { get; set; }
    [DataMember]
    public string SearchTerm { get; set; }
}

The RestService annotation is telling ServiceStack “put it here, and make the URL’s like this”. Based on the above, calls to /events/page/2 will pass in the number 2 for Page, and calls to /events/search/foo will pass in the search term foo. Now we should create our response object:

EventResponse

[DataContract]
public class EventResponse
{
    [DataMember]
    public IList<Event> EventListings { get; set; }
    [DataMember]
    public int RecordsPerPage { get; set; }
    [DataMember]
    public int CurrentPage { get; set; }
    [DataMember]
    public int? NextPage { get; set; }
    [DataMember]
    public bool IsLastPage { get; set; }
}

And that’s it! At this point your test should pass1, and not only this but if you visit /metadata you’ll see that ServiceStack has nailed up REST, CSV, JSV, JSON and SOAP services for you.

1 there are hosting details to work out as well, but it’s minimal. Check out the examples at www.servicestack.net for more details or view the complete project

Note Service Stack Series

This article is one of a three part series on Service Stack.
View All Articles
View Complete Source Code

2 thoughts on “Like WCF: Only Cleaner

  1. Pingback: JQueryMobile and Service Stack: EventsManager tutorial post #2 « Payment Networks

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s