Hi,

subscription and selector-filtering (the one applied by the isSelected) happen in two very different moment in the life of a Lightstreamer adapter.

The subscription on the DataProvider for an item X is performed when the first client subscribes to such item X: after that the DataProvider should start producing updates for that item.
If other clients subscribe to item X the subscribe call is not issued on the DataProvider.
The Unsubscribe call for item X will be called on the DataProvider only when there are no more clients subscribed to such item.
The Subscribe will be called again on the first client that subscribes again to item X.

The isSelected method is called whenever a new update is injected by the DataProvider into its ItemEventListener. As you can see that method is bound to an item, an user and a selector: the method is called once per each client connected and subscribed to that item; so the method choose whenever to let the server send the update to a client or to block it.


HTH.