*/
package org.opendaylight.mdsal.binding.api;
-import javax.annotation.Nonnull;
-import org.opendaylight.yangtools.concepts.ListenerRegistration;
+import org.eclipse.jdt.annotation.NonNull;
+import org.opendaylight.yangtools.concepts.Registration;
import org.opendaylight.yangtools.yang.binding.DataObject;
/**
* A {@link BindingService} which allows users to register for changes to a subtree.
*/
public interface DataTreeChangeService extends BindingService {
+ /**
+ * Registers a {@link DataTreeChangeListener} to receive notifications when data changes under a given path in the
+ * conceptual data tree.
+ *
+ * <p>
+ * You are able to register for notifications for any node or subtree which can be represented using
+ * {@link DataTreeIdentifier}.
+ *
+ * <p>
+ * You are able to register for data change notifications for a subtree or leaf even if it does not exist. You will
+ * receive notification once that node is created.
+ *
+ * <p>
+ * If there is any pre-existing data in the data tree for the path for which you are registering, you will receive
+ * an initial data change event, which will contain all pre-existing data, marked as created.
+ *
+ * <p>
+ * This method returns a {@link Registration} object. To "unregister" your listener for changes call the
+ * {@link Registration#close()} method on the returned object.
+ *
+ * <p>
+ * You MUST explicitly unregister your listener when you no longer want to receive
+ * notifications. This is especially true in OSGi environments, where failure to
+ * do so during bundle shutdown can lead to stale listeners being still registered.
+ *
+ * @param treeId Data tree identifier of the subtree which should be watched for changes
+ * @param listener Listener instance which is being registered
+ * @return a Registration object, which may be used to unregister your listener using {@link Registration#close()}
+ * to stop delivery of change events.
+ */
+ <T extends DataObject> @NonNull Registration registerDataTreeChangeListener(@NonNull DataTreeIdentifier<T> treeId,
+ @NonNull DataTreeChangeListener<T> listener);
+
/**
* Registers a {@link DataTreeChangeListener} to receive
- * notifications when data changes under a given path in the conceptual data
- * tree.
+ * notifications when data changes under a given path in the conceptual data tree.
*
* <p>
* You are able to register for notifications for any node or subtree
* which can be represented using {@link DataTreeIdentifier}.
*
* <p>
- * You are able to register for data change notifications for a subtree or leaf
- * even if it does not exist. You will receive notification once that node is
- * created.
+ * This method returns a {@link Registration} object. To
+ * "unregister" your listener for changes call the {@link Registration#close()}
+ * method on the returned object.
+ *
+ * <p>
+ * You MUST explicitly unregister your listener when you no longer want to receive
+ * notifications. This is especially true in OSGi environments, where failure to
+ * do so during bundle shutdown can lead to stale listeners being still registered.
+ * @implSpec This method provides {@link DataListenerAdapter} as listener during
+ * the registration of {@link DataTreeChangeListener}. This would allow users
+ * to know the last state of data instead of getting details about what changed
+ * in the entire tree.
+ * @param treeId Data tree identifier of the subtree which should be watched for
+ * changes.
+ * @param listener Listener instance which is being registered
+ * @return Listener registration object, which may be used to unregister
+ * your listener using {@link Registration#close()} to stop
+ * delivery of change events.
+ */
+ default <T extends DataObject> @NonNull Registration registerDataListener(
+ final @NonNull DataTreeIdentifier<T> treeId, final @NonNull DataListener<T> listener) {
+ return registerDataTreeChangeListener(checkNotWildcard(treeId), new DataListenerAdapter<>(listener));
+ }
+
+ /**
+ * Registers a {@link DataTreeChangeListener} to receive
+ * notifications about the last data state when it changes under a given path in the conceptual data
+ * tree.
*
* <p>
- * If there is any pre-existing data in the data tree for the path for which you are
- * registering, you will receive an initial data change event, which will
- * contain all pre-existing data, marked as created.
+ * You are able to register for notifications for any node or subtree
+ * which can be represented using {@link DataTreeIdentifier}.
*
* <p>
- * This method returns a {@link ListenerRegistration} object. To
- * "unregister" your listener for changes call the {@link ListenerRegistration#close()}
+ * This method returns a {@link Registration} object. To
+ * "unregister" your listener for changes call the {@link Registration#close()}
* method on the returned object.
*
* <p>
* notifications. This is especially true in OSGi environments, where failure to
* do so during bundle shutdown can lead to stale listeners being still registered.
*
- * @param treeId
- * Data tree identifier of the subtree which should be watched for
+ * @implSpec This method provides {@link DataChangeListenerAdapter} as listener during
+ * the registration of {@link DataTreeChangeListener}, which provides a comparison
+ * of before-value and after-value.
+ *
+ * @param treeId Data tree identifier of the subtree which should be watched for
* changes.
- * @param listener
- * Listener instance which is being registered
+ * @param listener Listener instance which is being registered
* @return Listener registration object, which may be used to unregister
- * your listener using {@link ListenerRegistration#close()} to stop
+ * your listener using {@link Registration#close()} to stop
* delivery of change events.
*/
- @Nonnull <T extends DataObject,L extends DataTreeChangeListener<T>> ListenerRegistration<L>
- registerDataTreeChangeListener(@Nonnull DataTreeIdentifier<T> treeId, @Nonnull L listener);
+ default <T extends DataObject> @NonNull Registration registerDataChangeListener(
+ final @NonNull DataTreeIdentifier<T> treeId, final @NonNull DataChangeListener<T> listener) {
+ return registerDataTreeChangeListener(checkNotWildcard(treeId), new DataChangeListenerAdapter<>(listener));
+ }
+
+ private static <T extends DataObject> @NonNull DataTreeIdentifier<T> checkNotWildcard(
+ final DataTreeIdentifier<T> treeId) {
+ final var instanceIdentifier = treeId.path();
+ if (instanceIdentifier.isWildcarded()) {
+ throw new IllegalArgumentException("Cannot register listener for wildcard " + instanceIdentifier);
+ }
+ return treeId;
+ }
}
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Code Review / mdsal.git / blobdiff