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Use `@Component` annotation instead of XML in Event Bus example code (#2217) 

Using these DS Component annotations is more convenient and is used everywhere else in the code nowadays.

Signed-off-by: Wouter Born <github@maindrain.net>
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Wouter Born 2024-01-26 22:32:58 +01:00 committed by GitHub
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developers/utils/events.md
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@ -113,6 +113,7 @@ The following Java snippet shows how to receive `ItemStateEvent`s and `ItemComma
Therefore, the `EventSubscriber` interface must be implemented. Therefore, the `EventSubscriber` interface must be implemented.
```java ```java
@Component(immediate = true, service = EventSubscriber.class)
public class SomeItemEventSubscriber implements EventSubscriber { public class SomeItemEventSubscriber implements EventSubscriber {
private final Set<String> subscribedEventTypes = Set.of(ItemStateEvent.TYPE, ItemCommandEvent.TYPE); private final Set<String> subscribedEventTypes = Set.of(ItemStateEvent.TYPE, ItemCommandEvent.TYPE);
@ -157,15 +158,7 @@ If the filter applies (in the given example for all item events with the item na
Received events can be cast to the event implementation class for further processing. Received events can be cast to the event implementation class for further processing.
Each event subscriber must be registered via OSGi Declarative Services (DS) under the `org.openhab.core.event.EventSubscriber` interface. Each event subscriber must be registered via OSGi Declarative Services (DS) under the `org.openhab.core.event.EventSubscriber` interface.
This is done by annotating the class with `@Component(immediate = true, service = EventSubscriber.class)`.
```xml
<scr:component xmlns:scr="https://www.osgi.org/xmlns/scr/v1.1.0" immediate="true" name="SomeItemEventSubscriber">
<implementation class="org.openhab.core.items.events.SomeItemEventSubscriber"/>
<service>
<provide interface="org.openhab.core.events.EventSubscriber"/>
</service>
</scr:component>
```
The listing below summarizes some best practices in order to implement event subscribers: The listing below summarizes some best practices in order to implement event subscribers:
@ -190,6 +183,7 @@ Due to the fact that receiving `ItemStateEvents` and `ItemCommandEvents` is a co
The class `org.openhab.core.items.events.AbstractItemEventSubscriber` provides two methods `receiveUpdate(ItemStateEvent)` and `receiveCommand(ItemCommandEvent)` which can be implemented in order to receive and handle such events. The class `org.openhab.core.items.events.AbstractItemEventSubscriber` provides two methods `receiveUpdate(ItemStateEvent)` and `receiveCommand(ItemCommandEvent)` which can be implemented in order to receive and handle such events.
```java ```java
@Component(immediate = true, service = EventSubscriber.class)
public class SomeItemEventSubscriber extends AbstractItemEventSubscriber { public class SomeItemEventSubscriber extends AbstractItemEventSubscriber {
private final EventFilter eventFilter = new TopicEventFilter("openhab/items/ItemX/.*"); private final EventFilter eventFilter = new TopicEventFilter("openhab/items/ItemX/.*");