Hi,
Respectfully, I believe that for WCF Data Services it should be 'Server side sorting, filtering, paging and projections support' as a pro. Not just 'paging'.

Shawn,
Thanks for this, it's very useful.

-Damien

So Shawn, given those 3, what are you using on your line of business Silverlight 4 apps ?

WCF RIA Services supports eager loading. You have to use [Include] attributes on metadata + Include methods in domain service methods .

Any thoughts on which one works best in partnership with MVVM ?

What about REST services with JSON/POX?

Przemek Soszynski,

Do you mean WCF Web Services?

Steve,

It depends...

Its a bad answer but that's the fact. I tend to lean towards WCF Data Services because I like the caller being able to control the query, but that doesn't work in harded security situations.

Anon,

That's support for eager loading in the model, not in the query. I can't do eager loading on a query by query or operation by operation basis.

Jim,

Because you typically hide the data access in the Model, you can do all three equally well in MVVM.

Eric,

I don't see that as a common scenario as you are doing weakly typed results. You can do it and its similar to the Web Services story, but there are no benefits beyond what you see in Web Services for REST POX/JSON except perhaps message size, but binary encoding message bodies in Web Services + GZip means size is really similar.

I would have split up the WCF services into SOAP/ASMX and REST based implementations. Consuming them is different between the pattern you select. In fact, REST based services don't even need to be WCF.

BTW...do you know if batching is supported in WCF RIA Services? I know in WCF Data Services...batching can be turned on.

@Shawn. I mean WCF Data Services with OData. I have been using it for some time now. I am able to do paging, sorting and filtering on server. The linq queries are translated into url and executed on the server. Sorted, paged data comes back to the client.

Przemek Soszynski,

That's exactly what I mean by client-side paging, filtering, sorting and projections. They are defined on the client, performed by the server.

Bart,

WCF RIA Services can batch changes to the server. They just can't batch SELECTs.

I understand why you'd want to separate them, but I don't think the use-case for REST being large enough for Silverlight specifically to divide it up, but its a good comment.

I agree with everything you've said here.

I've been going the web services (WCF) route with my Silverlight 4 projects. Fortunately, most of my projects thus far haven't had to deal with any data versioning or change tracking.

Also, using some open source projects like AutoMapper and FluentValidation relieves some of the efforts related to code bloat and manual validation.

Are you only reviewing solutions provided by Microsoft? Would it be worth mentioning 3rd party open source and/or commercial options? Have you looked into IdeaBlade's DevForce for Silverlight?

Bobby,

I am open to open source/commercial options I just haven't had time to look at them. I've talked to Ward Bell (of Idea Blade) about it at length and I think it might be a viable solution but as I haven't dedicated time to review it I can't speak to it.

Shawn,
RIA Services already support server-driven paging; e.g. adding the following attrib to a query method in a DomainService causes results to be capped at 100 objects - all enforced on server.
[Query(ResultLimit=100)]

The end-to-end manifestation is more suitable for RIA scenarios rather than a wide open service but the goal is the same. Server decided how many results to send. The client can choose fewer but will not get more. This can be added to the OData endpoint of DomainService as well in future.

Thanks Dinesh, I didn't know. Are there any solutions like Continuations with the result limits?

I would like to say that I have been using DevForce 2010 / by IdeaBlade and it is by far the best current solution for Silverlight Data access. Their approach is light years ahead of everything else at the moment; of course this can change when “Monkey Coder “is released. The Silverlight piece is under a grand and they have a free D/L for developers to learn the tool. Check it out.

Hi..
and how do you comapare thouse technologies with Ideablade Devforce 2010??

Thanks

Hi Shawn,

I've tested both, and was disappointed by both. I don't think it is possible to built a professionnal product with those (without writing your own heavy business wrapper).

Finally I tested and adopted CSLA for silverlight. Hard to learn but really powerfull. My project is still under development, but I believe that I won't come back from it...

Did someone test it? Any experiences? Why doesn't it have a larger audience?

Christophe