Investigate subscribe() and init() in a single message

[uklance]

Currently push.js first sends config on the '/service/pushInit' channel before subscribing to the actual channel.

Looking at cometd-javascript\common\src\main\js\org\cometd\Cometd.js it might be possible to pass properties in the subscribe() function. If this is possible, we could remove the '/service'pushInit' and avoid possible race conditions with disconnect()

I think this cannot be done with a SubscriptionListener (since the actual message is not passed to the listener).

It might be possible to hack it with an Authorizer. http://docs.cometd.org/apidocs/org/cometd/bayeux/server/Authorizer.html

Another option is to subscribe to the '/meta/subscribe' channel.

    /**
     * Subscribes to the given channel, performing the given callback in the given scope
     * when a message for the channel arrives.
     * @param channel the channel to subscribe to
     * @param scope the scope of the callback, may be omitted
     * @param callback the callback to call when a message is sent to the channel
     * @param subscribeProps an object to be merged with the subscribe message
     * @return the subscription handle to be passed to {@link #unsubscribe(object)}
     */
    this.subscribe = function(channel, scope, callback, subscribeProps)
    {
        ...
    };

[uklance]

Done with an authorizer