Removing, replacing ItemUpdate positions

Killmister

Hello LightStreamer team. In the android app i am developing, there is an option to replace and delete stocks from the UI. When those values are changed after the first subscription, I have to update the adapter to send me correct ItemUpdate positions. The problem am facing is with the graphs update. For setting the new itemUpdate positions first I have to unsubscribe and register the observer again, which is causing redrawing of the graphs once again when ls.Client.subscribe() is called. I tried the setItems method, but it also requires unsubscription, so the result is the same. Is there some way to update the correct positions without unsubscribing? The adapter is set in DISTINCT mode

Despite of my problem everything is working amazing, great job and sorry if the question is already asked, I couldn’t find similar issue in the forum

Giuseppe Corti

Hi Killmister,

Unfortunately I have to confirm that it is not possible to change the position in ItemUpdate without perform an unsubscribe (followed by a new subscribe).
Indeed, although I didn't know so much about your application, I am not sure if the chosen subscription mode is the better one to feet the UI requirements.
Generally, in cases where the items requested by the client may vary continuously over time, there are two favored subscription strategies:

- A single Item in COMMAND mode, where the list of subscribed stocks is updated directly with special updates from the server;
- multiple Items in DISTINCT or MERGE mode subscribed to with different subscribe calls. This allows you to add and remove stocks separately without affecting the other subscriptions.

I am inclined to the second option for your case, you can also refer to this demo that does something similar: https://demos.lightstreamer.com/GridDemo/

Please let us know if you have already considered these subscription options and if you need any further clarifications.

Regards,
Giuseppe