3

We are in the start phase of defining a client-server architecture based on WWSAPI.

One of our services should allow the client to connect and subscribe to some data updates based on certain criteria. This data should then be delivered, when created or updated, through a callback from the server to the client.

In WCF, it is possible to use duplex channels that allows the client to provide a callback for the server, however I've read that duplex channels are not supported with WWSAPI.

Is this correct? We already have good experience with defining a duplex service in WCF and consume it with a WWSAPI client, but is it possible to also define a duplex service with WWSAPI?

Does anyone have any good examples on this? It's really hard to find good WWSAPI examples in the midst of all the WCF info out there...

Update: 3 views in a week! Re-tagged with C++

havardhu
  • 3,576
  • 2
  • 30
  • 42

2 Answers2

0

Look at the TCP Channel Layer Examples, the RequestReply Client/Server are your solution.

esskar
  • 10,638
  • 3
  • 36
  • 57
  • Can one request from the client generate multiple replies from the service? It seems unclear from the documentation (if you could even call it that) – havardhu Nov 24 '11 at 09:24
  • Very old comment, but I'm thinking the same thing. This is still 1 to 1 communication between server and client isn't it? Did you ever find a straightforward way of sending updates to your client? – lhbortho Jun 16 '17 at 15:51
0

Since you mentioned being able to consume a WCF duplex service with a WWSAPI client, I encountered the same restriction and worked around it by implementing a WCF service that sits between the client and server. Our's is a router but that isn't strictly necessary. It polls the WWSAPI server periodically and then does a callback to the client if the value has updated. While not ideal as there will be a balance between lag between update and callback versus load on the server with the polling, it does work.

In our case we were using WCF clients, but as mentioned above you appear to have gotten the WWSAPI --> WCF duplex service working already.

dlanod
  • 8,664
  • 8
  • 54
  • 96