Allow ThingHandlers to dynamically register services (#4719)

Signed-off-by: Cody Cutrer <[email protected]>

Author: ccutrer

Diff for: bundles/org.openhab.core.thing/src/main/java/org/openhab/core/thing/binding/BaseThingHandlerFactory.java

@@ -161,6 +161,23 @@ private void registerServices(Thing thing, ThingHandler thingHandler) {
         }
     }
 
+    /**
+     * Registers a dynamic service for the given thing handler. The service must implement ThingHandlerService.
+     * 
+     * @param thingHandler The thing handler requesting a service to be registered.
+     * @param klass The service class to register.
+     */
+    public void registerService(ThingHandler thingHandler, Class<? extends ThingHandlerService> klass) {
+        ThingUID thingUID = thingHandler.getThing().getUID();
+        if (!ThingHandlerService.class.isAssignableFrom(klass)) {
+            logger.warn(
+                    "Should register service={} for thingUID={}, but it does not implement the interface ThingHandlerService.",
+                    klass.getCanonicalName(), thingUID);
+            return;
+        }
+        registerThingHandlerService(thingUID, thingHandler, klass);
+    }
+
     private <T extends ThingHandlerService> void registerThingHandlerService(ThingUID thingUID,
             ThingHandler thingHandler, Class<T> c) {
         RegisteredThingHandlerService<T> registeredService;