2 * Copyright (c) 2018 Pantheon Technologies, s.r.o. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
8 package org.opendaylight.mdsal.dom.api;
10 import com.google.common.annotations.Beta;
12 import org.eclipse.jdt.annotation.NonNullByDefault;
13 import org.opendaylight.yangtools.concepts.Registration;
14 import org.opendaylight.yangtools.yang.data.api.schema.ContainerNode;
15 import org.opendaylight.yangtools.yang.model.api.stmt.SchemaNodeIdentifier.Absolute;
18 * A {@link DOMActionService.Extension} exposed by {@link DOMActionService}s which allow their users to listen
19 * for actions are becoming available.
23 public interface DOMActionAvailabilityExtension extends DOMActionService.Extension {
25 * Register a {@link AvailabilityListener} with this service to receive notifications about operation
26 * implementations becoming (un)available. The listener will be invoked with the current implementations reported
27 * and will be kept uptodate as implementations come and go.
30 * Users should note that using a listener does not necessarily mean that
31 * {@link DOMActionService#invokeAction(Absolute, DOMDataTreeIdentifier, ContainerNode)} will not report
32 * a failure due to {@link DOMActionNotAvailableException} and need to be ready to handle it.
35 * Implementations are encouraged to take reasonable precautions to prevent this scenario from occurring.
37 * @param listener {@link AvailabilityListener} instance to register
38 * @return A {@link Registration} representing this registration. Performing a {@link Registration#close()} will
40 * @throws NullPointerException if {@code listener} is null
42 Registration registerAvailabilityListener(AvailabilityListener listener);
45 * A listener used to track Operation implementations becoming (un)available to a {@link DOMActionService}.
47 interface AvailabilityListener {
49 * Method invoked whenever an action type becomes available or unavailable. There are two sets reported,
50 * removed and added. To reconstruct the state, first apply removed and then added operations, like this:
53 * Set<DOMActionInstancelt;?>> operations;
54 * operations.removeAll(removed);
55 * operations.addAll(added);
58 * @param removed operations which disappeared
59 * @param added operations which became available
61 void onActionsChanged(Set<DOMActionInstance> removed, Set<DOMActionInstance> added);
64 * Implementation filtering method. This method is useful for forwarding operation implementations,
65 * which need to ensure they do not re-announce their own implementations. Without this method
66 * a forwarder which registers an implementation would be notified of its own implementation,
67 * potentially re-exporting it as local -- hence creating a forwarding loop.
69 * @param impl Operation implementation being registered
70 * @return False if the implementation should not be reported, defaults to true.
72 default boolean acceptsImplementation(final DOMActionImplementation impl) {