Esper: detect event start only

Question

I'm new to Esper (NEsper, actually) and I've been trying (unsuccesfully) to create an statement to detect when an event starts.

For example, suppose I have an event type called "Started betting" and I want to consider it is happening after 10 minutes of having "proof" of that. With what I've been using as the statement, after 10 minutes the update() method is triggered every time there is "proof".

I've tried something like

from (...), StartedBetting as st 
where st is null AND (...) 

but didn't work (event was never detected).

Hope I've made myself clear.

Any hints will be appreciated.

Answer 1

So if I understand you right, when receiving any start-betting event you simply want to delay for 10 minutes and then get called? The "proof" part is not clear. But this would do it:

select * from pattern [every StartBetting -> timer:interval(10 min)]