net.esper.pattern
Interface PatternStarter
- All Known Implementing Classes:
- EvalRootNode
public interface PatternStarter
Interface for observing when an event expression needs to start (by adding the first listener).
The publishing event expression supplies the callback used for indicating matches. The implementation supplies
as a return value the callback to use to stop the event expression.
start
PatternStopCallback start(PatternMatchCallback matchCallback,
PatternContext context)
- An event expression was started and supplies the callback to use when matching events appear.
Returns the callback to use to stop the event expression.
- Parameters:
matchCallback
- must be supplied to indicate what to call when the expression turns truecontext
- is the context for handles to services required for evaluation.
- Returns:
- a callback to stop the expression again