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DF Silverlight - "Subscribe to server events"

Printed From: IdeaBlade
Category: DevForce
Forum Name: DevForce 2009
Forum Discription: For .NET 3.5
URL: http://www.ideablade.com/forum/forum_posts.asp?TID=1406
Printed Date: 05-Apr-2025 at 8:51am


Topic: DF Silverlight - "Subscribe to server events"
Posted By: philcockfield
Subject: DF Silverlight - "Subscribe to server events"
Date Posted: 01-Aug-2009 at 4:04pm
On page 21 of the developer manual (v5.2) it says (in relation to DF for Silverlight):

"The client can request non-data services to be executed on the server and subscribe to server events."

Where do I look for this feature? The closest thing I can find is "Push Notification", on page 440, however here it says that this feature is not available for SL.

Any help or pointers or general patterns on how to handle events emanating from the server and flowing back to the client would be really helpful. Thanks!


Replies:
Posted By: kimj
Date Posted: 04-Aug-2009 at 10:08am

I think that chapter may need a little re-work.  Push, which does allow the client to receive notifications (events, data, whatever) from the server, is not currently available in DevForce Silverlight.  We do support various server-side features and "event handlers" - eg, IEntityLoginManager, IEntityServerFetch*, IEntityServerSav*, POCO providers, and a few more.  There's also the InvokeServerMethodAsync call from the client which can be used as a kind of back door to server methods.

What kind of server events are you interested in? 
 

Posted By: philcockfield
Date Posted: 04-Aug-2009 at 10:18am
>> What kind of server events are you interested in?

I'm interested in being able to update UI when changes occur to entities on the server.

I'm scouting around for best approaches to doing this, from gross "Polling" of the server through to some kind of clean duplex network protocol.

There's some promise in the WCF Duplex Service, but I haven't dug into that yet. I saw the reference and wondered if you guys had crossed that bridge already with DevForce 4 SL.

Posted By: kimj
Date Posted: 04-Aug-2009 at 10:50am
When we implement Push in DevForce Silverlight, it will be as a WCF duplex service (that's how it's implemented in both DevForce Classic and Universal), but unfortunately we haven't yet taken the plunge.  It is on the horizon, but the feature request hasn't bubbled to the top of our queue yet. 
 
(If I were in your position I'd probably look at writing a duplex service, and either sending the changed data to the client as an EntityCacheState or else as a message telling the client to re-execute a query.) 

Posted By: philcockfield
Date Posted: 04-Aug-2009 at 11:01am
Awesome ... thanks for the guidance.

Posted By: skingaby
Date Posted: 08-Oct-2009 at 12:46pm
Any further news on this? We have a multiuser Silverlight app where it is very likely that simultaneous changes will be made to entities and those changes need to be pushed out to the other clients in real time. Thanks.

Posted By: kimj
Date Posted: 08-Oct-2009 at 12:55pm
Unfortunately, we still haven't implemented Push in DevForce Silverlight.  It's a possibility for our December release, but not definite.

Posted By: foxy1982
Date Posted: 09-Feb-2010 at 1:11pm
Hi,

did this make it into the Silverlight release in December?

Thanks

Posted By: skingaby
Date Posted: 11-Feb-2010 at 10:23am
No. I for one am still hoping it makes it into the March release.


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