I''m trying to get a better understanding of the difference between these two interfaces and when it is better to use which. My scenario is that I have a wildfire plugin that attaches some information to each user''s Presence on the server. What I want to do is have a spark client plugin that is able to handle the modified Presence object being sent to the spark clients and have my code update each of the contacts'' presence info displayed in the client.
Based on the API docs, both these interfaces seem to capture when a user''s presence changes. My question is "which should I use to be able to examine the custom presence object sent from the server?"