WCF server and client communication
Posted on 2009-07-15
I've run into a bit of a complication with my WCF server app. I'm trying to add an event handler to a custom object so that when the data changes the server calls all the clients that are subscribed to that particular object and notifies them of the update. My problem is, how in the world do I call specific clients from the server?
I know a bit about the CallBack feature but I'm unsure how I would only issue this to certain clients, and to my knowledge this only calls back one client, the one who initiated the call to begin with. I hope this all makes sense. It is crucial I figure this out to get my record locking mechanism to work. I've attempted to search for this answer however I'm not too sure what to even search for so if someone could point me in the right direction I would sure appreciate it. I am using VB so any examples in that format would be most helpful though I'd settle for C#.
P.S. To elaborate on my intentions: A client requests edit privileges from the server and the server grants them. The server then issues a lock command to the other client viewing the exact same record. Those clients will see a padlock appear showing the record is locked and cannot be edited until released by the editor. When the editor saves the record, the server should call all other subscribed clients and tell them to update and unlock. Hope this makes it a bit clearer.