io.spine.server.entity

Interface EventFilter

All Known Implementing Classes:

CompositeEventFilter, EventBlackList, EventFieldFilter, EventWhiteList

@SPI
 @FunctionalInterface
public interface EventFilter

A filter accepting Events posted by a Repository.

A filter may allow any event, reject certain types of events, or change the event content.

API Note:

This type is a FunctionalInterface, so that an event filter may be defined with a lambda expression.

Method Summary

Modifier and Type	Method and Description
static EventFilter	allowAll() Obtains an EventFilter which always returns the input event without any change.
default com.google.common.collect.ImmutableCollection<io.spine.core.Event>	filter(java.util.Collection<io.spine.core.Event> events) Applies this filter to the given Events in bulk.
java.util.Optional<? extends io.spine.base.EventMessage>	filter(io.spine.base.EventMessage event) Applies this filter to the given event.

Method Detail

allowAll

static EventFilter allowAll()

Obtains an EventFilter which always returns the input event without any change.

The method acts as if

     
     static EventFilter allowAll() {
         return Optional::of;
     }
     
 

Returns:

a filter which allows any event to be published

filter

java.util.Optional<? extends io.spine.base.EventMessage> filter(io.spine.base.EventMessage event)

Applies this filter to the given event.

Parameters:

event - the event to apply the filter to

Returns:

processed event or Optional.empty() if the event should not be posted

API Note:

This method may never return a present value or return a value not derived from the input event. See the implementations for the details for each case.

filter

default com.google.common.collect.ImmutableCollection<io.spine.core.Event> filter(java.util.Collection<io.spine.core.Event> events)

Applies this filter to the given Events in bulk.

Parameters:

events - the events to apply the filter to

Returns:

non-empty filtering results for the given events

API Note:

This method should have the same behaviour in any descendant. Override this method only for performance improvement.