Note that in data centric systems, that is, systems that depend heavily on data, the data can come from disparate systems. Now, your application would need to have the business logic objects and other server objects reside on the client side so that you can access the data.
The major problem with this type of approach is the duplication of code, and also the high consumption of memory resources at the client side. This is where WCF 4.5 RIA Services comes to the rescue. Incidentally, WCF 4.5 RIA Services was introduced in .NET Framework 4 and Silverlight 4. It allows developers to design and implement applications sans the need of a service plumbing code.
The following diagram illustrates the architectural components of a typical WCF 4.5 RIA Services application:
WCF 4.5 RIA Services (built on top of the WCF 4.5 services) simplifies n-tier application development (especially applications that use Silverlight) without you having to write a service plumbing code. In essence, if you use WCF 4.5 RIA Services, your application logic can reside on the server. This can be made available to the client without the need of duplication of the application's logic components on the client side, that is, at the service consumer's end. RIA services are built on top of WCF 4.5, and simplify the client-side programming model. However, there are a few potential drawbacks of RIA services too. Most importantly, working with metadata is a pain, especially when you need to update your model often. If you have a database that contains many entities, you would end up spending more time updating your model when you are using RIA services.
Here is a quick look at the features provided by WCF 4.5 RIA Services:
- When you use WCF 4.5 RIA Services, the client-side instances are created through a reflection depending on the server-side objects, in lieu of service contracts, that are exposed by the services that execute on the server.
- WCF 4.5 RIA Services provide support for serializing LINQ queries; so, you can write your LINQ queries at the client side and execute it at the server end.