What is the best model for using services in a silverlight application?
I usually add a wcf service to my ASP.net app and add a service reference to my silverlight application, but anytime I change my service I should update the service reference in silverlight app.
Is there any better and more professional way?
If you use WCF RIA Service instead of a plain WCF service, it will automatically be updated whenever something on the service end changes.
If you continue to use plain WCF, you will need to update the service anything you change something.
You can also write your own model and expose them to the silverlight client, just like WCF. Everything is almost the same, except ria services was built for this purpose and more.
Related
I have a WCF service (using HTTP binding) that our WinForm and WFP apps can use with no problem. We have a Silverlight 4 developer who is saying he's not able to use the WCF service because it needs to be "reconfigured" for Silverlight use. I don't know if this is true or not, because I don't know anything about Silverlight.
So, my question is this. Should a WCF service, that uses HTTP binding, that is successfully being used by our WinForms and WPF applications, also be able to be consumed by Silverlight apps, without modifying or reconfiguring the WCF service?
Silverlight 4 supports the following bindings:
BasicHttpBinding
PollingDuplexHttpBinding
CustomBinding (with a subset of binding elements)
Silverlight and WCF Feature Comparison:
There are several ways to use the WCF
client stack to access a service.
It is used when invoking services
through automatically generated
proxies, as described in How to:
Access a Service from Silverlight. The
proxy must be generated in this
procedure by using the Add Service
Reference tool in Visual Studio 2010
for the Silverlight project.
Caution:
Proxies generated by using the WCF
Svcutil.exe tool will not work in
Silverlight 4. Use the SLsvcutil.exe
tool instead. For more information
about using this Silverlight tool, see
Using SLsvcUtil.exe to Access a
Service.
If you already have a Windows
Communication Foundation (WCF) service
contract definition, you can use the
generic ChannelFactory class without
having to generate a proxy. This might
be the case, for example, if your
client is sharing service definition
code with the project on the server.
In this case you could, for example,
define a service contract interface
IStockQuoteService and then use the
same IStockQuoteService code in both
the server and Silverlight projects.
This would involve using a
ChannelFactory.
This advanced technique is
demonstrated in How to: Call
Operations Asynchronously Using a
Channel Factory and in the Silverlight
4 context with Building and Accessing
Duplex Services. For more information
about defining and using service
contracts, see Designing Service
Contracts.
I'd like my WP7 to be able to talk to a service on my local computer. For various reasons it would be more convenient if this service was hosted in a custom host, i.e. an app running locally. However, if I understand correctly "Silverlight-enabled WCF service" need asp.net compatibility, therefore must be hosted in IIS, is this correct?
If so, is there anyway to work round this and get a "Silverlight-enabled WCF service" running in a custom host?
The Silverlight-enabled WCF Service is just a simplified item template from a regular WCF service. It was originally added because the default binding for WCF services wasn't supported in Silverlight, and caused a lot of angst for new Silverlight developers. You should be able to use the regular WCF item in a regular project (e.g. console app) and you'll just have to adjust the bindings.
(Also of note is that the Silverlight-enabled WCF template uses a single code file instead of separating out the service interface from the class implementation.)
I have my silverlight calling my WCF service and its working great. This is a WCF (not ria) service that basically returns enitites or collection of entities.
I really don't have control over it to add additional items just for silverlight for example.
So i was thinking but maybe its bad performance or desgin..
But to have a local WCF Service hosted with the Asp.net website that hosts silverlight.. ANd i can use this wcf service for business logic that doesn't need to return entities. For example so silverlight can call to the server and then the server can do something with PURE .net.
Of course i still will need my silverlight to talk to my External WCF service that returns entities etc..
What would be the best way to implement this, if at all..
Silverlight calls local WCF service and "IF REQUIRED" local wcf service calls external WCF Service (which returns entities etc) and everything is returned back down the chain.
or Silverlight calls to local WCF service or to external WCF service depending on what is required.
There is a 3rd option but i am thinking aloud and maybe it wouldn't fit... But to have RIA services so silverlight could call this .... but again I CANNOT get rid of or have control over my other wcf service... So silverlight would need to call both OR ria services could call the wcf service ... But this is where i have a doubt... because RIA services normally return IQUERYABLE for example... My wcf service returns ILIST for example so if ria services called to my wcf service it would receive back an ILIST .. hence the [QUERY] attribute in ria services require me to return IQUERYABLE but it isn't possible because i am already in an ILIST.
I would really appreciate some feedback to weather i am completely missing the point or infact its a good idea.
The fact remains that silverlight sometimes needs to do standard stuff on the server but has nothing to do with dataaccess or entities... i have no control over the external wcf service so i can't just insert a new method specifically for silverlight when its needed..
Anybody use a similar system, PROS / CONS??
Thanks in advance
I think your application should use only Ria Services and then Ria service should connect to the external service. Then all logic is on the server and your SL app has simple model of using services. You can think about is as all business logic is on the server.
What about returning IQueryable you always can "convert" list to IQueryable using linq, but I think you can return list from RIA Service - it shoudn't be a problem.
Im porting an "old" silverlight 3 app that used WS* webservices to connect. These services have been changed and are now replaced by an WCF "equivalent". I cant seem to get my silverlight app to work with the WCF service, I add a reference to the: http.....svc and create my client, but the clientConfiguration is empty. The silverlight app doesnt know the datatypes given in the WCF service... all this is working well in the WPF client also using them...
All i seem to get on one of my types from the WCF service is a public variable called "data"... anyone know what this is?
Sincerely,
WCF for silverlight support a subset of bindings for normal WCF. As the time of siverlight4, we support basic http binding, nettcp binding and pollingduplex binding. For nettcp binding, it has some port restriction and requires you setup some policy server. You can find more details on http://msdn.microsoft.com/en-us/library/cc896571(VS.95).aspx
HTH
At the moment it seems that a RIA Domain Services class can not return a sinlge custom type.
There are parts of my app that needs just that, so think the only way to get that is to call back to a simple silverlight-enabled WCF Service, which i beleive will not have a problem returning a custom type. I don't see where the Silverlight client app has any sort of reference to the Ria Services. How do I set up both a Ria services and WCF service on the silverlight client. Will the WCF service be "aware" of the authenication already in place with the RIA services?
This is one of my biggest bugbears of RIA Services :). The good thing is that they are in the process of enabling complex types to be returned from invoke methods (according to the user voice site for RIA Services). However, that won't help you now :).
The best way to implement your requirement to return complex objects is indeed to set up a standard WCF Service to return complex types when required. You do so in the normal way that you would expose a WCF in any web project. You then consume it in your Silverlight application in much the same way you would a WCF Service in any other type of project (by adding it as a service reference). The main difference when consuming it (compared to other types of projects) is that Silverlight only supports asynchronous calls. One difference to be aware of from RIA Services is that whereas RIA Services automatically determines the URI of the domain services (based upon where the XAP file originated from), you will need to handle that aspect yourself (very important when you try to deploy your application :). Do this either by setting the URI in the app.config file, or use the method I use in the code accompanying this article here: http://www.silverlightshow.net/items/Building-a-Framework-for-Silverlight-Line-Of-Business-Applications.aspx.
In regards to your final question, yes, RIA Services uses standard ASP.NET authentication, so the cookie that it uses to maintain your authentication status is also used by any WCF Services in the same project. I talk a bit about security with WCF Services in this article if you want more information: http://www.silverlightshow.net/items/Building-a-Silverlight-Line-Of-Business-Application-Part-3.aspx.
Hope this helps...
Chris