deliver data to cometd server using a channel

Question

How can I deliver some data to server side while subscribing to server?

As an example,

When I subscribing /alert/12345, I want to send some other information such as alert_type, date_time etc to CometD server.

Answer 1

You can pass a data map in subscribe:

cometd.subscribe(channelId, undefined, callback, { data: data })

But as far as I could see, you can only get a reference to the data map in org.cometd.bayeux.server.Authorizer. I couldn't get it via org.cometd.bayeux.server.BayeuxServer.SubscriptionListener because there is no reference to the ServerMessage.

You can see my use of it here:

• https://github.com/uklance/tapestry-cometd/blob/master/src/main/resources/org/lazan/t5/cometd/PushTarget.js#L37
• https://github.com/uklance/tapestry-cometd/blob/master/src/main/java/org/lazan/t5/cometd/services/internal/AuthorizersImpl.java#L67