1 /**
2 * This file Copyright (c) 2015-2018 Magnolia International
3 * Ltd. (http://www.magnolia-cms.com). All rights reserved.
4 *
5 *
6 * This file is dual-licensed under both the Magnolia
7 * Network Agreement and the GNU General Public License.
8 * You may elect to use one or the other of these licenses.
9 *
10 * This file is distributed in the hope that it will be
11 * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
12 * implied warranty of MERCHANTABILITY or FITNESS FOR A
13 * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
14 * Redistribution, except as permitted by whichever of the GPL
15 * or MNA you select, is prohibited.
16 *
17 * 1. For the GPL license (GPL), you can redistribute and/or
18 * modify this file under the terms of the GNU General
19 * Public License, Version 3, as published by the Free Software
20 * Foundation. You should have received a copy of the GNU
21 * General Public License, Version 3 along with this program;
22 * if not, write to the Free Software Foundation, Inc., 51
23 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
24 *
25 * 2. For the Magnolia Network Agreement (MNA), this file
26 * and the accompanying materials are made available under the
27 * terms of the MNA which accompanies this distribution, and
28 * is available at http://www.magnolia-cms.com/mna.html
29 *
30 * Any modifications to this file must keep this entire header
31 * intact.
32 *
33 */
34 package info.magnolia.resourceloader;
35
36 import info.magnolia.resourceloader.util.ResourceTreeWalker;
37
38 import java.util.function.Predicate;
39 import java.util.stream.Stream;
40
41 /**
42 * Common interface for all resource file origins (e.g. file-system, classpath, JCR).
43 *
44 * @param <P> the type of {@link Resource} this implementation of ResourceOrigin produces.
45 */
46 public interface ResourceOrigin<P extends Resource> {
47
48 /**
49 * Returns the name of this origin. This may be used to describe/differentiate origin instances, and generate i18n keys accordingly.
50 */
51 String getName();
52
53 /**
54 * Returns the {@link Resource} for this origin's declared root.
55 */
56 P getRoot();
57
58 /**
59 * Traverses this ResourceOrigin from the root, according to the given {@link ResourceVisitor}.
60 *
61 * @see ResourceVisitor
62 * @see info.magnolia.resourceloader.util.PredicatedResourceVisitor
63 * @see info.magnolia.resourceloader.util.ResourceTreeWalker
64 */
65 void traverseWith(ResourceVisitor visitor);
66
67 /**
68 * Sets up observation for this origin, and hooks it to the given callback {@link ResourceVisitor}.
69 *
70 * @deprecated since 5.4.6 - use {@link #registerResourceChangeHandler(ResourceChangeHandler)} instead. Current method is less preferable to
71 * be used for resource changes monitoring because {@link ResourceVisitor} is not a suitable interface to communicate such changes. E.g. {@link ResourceVisitor}
72 * has no API to provide the context of the change (which {@link ResourceOrigin} the change has happened at, what was the type of the change etc). Also {@link ResourceVisitor} requires
73 * an instance of {@link Resource} - it is not usable to communicate deletion of resources.
74 *
75 * @see ResourceVisitor
76 * @see info.magnolia.resourceloader.util.PredicatedResourceVisitor
77 */
78 @Deprecated
79 void watchForChanges(ResourceVisitor visitor);
80
81 /**
82 * Hook the underlying resource change monitoring mechanism (if any) to a provided {@link ResourceChangeHandler handler}.
83 *
84 * @see ResourceOriginChange
85 */
86 ResourceChangeHandlerRegistration registerResourceChangeHandler(ResourceChangeHandler changeHandler);
87
88 /**
89 * Retrieves a {@link Resource} object based on the given path. The given path may or may not start with a
90 * leading /, but will always be considered relative to whatever root path this origin uses; for the user of this
91 * class, such paths should thus be considered absolute, depending on the implementation, they may be relative
92 * to some other path. Directory traversal navigation should be prohibited by implementations for security reasons.
93 *
94 * @throws ResourceNotFoundException if the path does not exist in this ResourceOrigin
95 */
96 P getByPath(String path);
97
98 boolean hasPath(String path);
99
100 /**
101 * Collect all resources matching provided predicate starting at the specified root.
102 */
103 default Stream<Resource> find(Resource root, Predicate<Resource> filter) {
104 Stream.Builder<Resource> result = Stream.builder();
105
106 new ResourceTreeWalker(new ResourceVisitor() {
107
108 @Override
109 public void visitFile(final Resource resource) {
110 if (filter.test(resource)) {
111 result.add(resource);
112 }
113 }
114
115 @Override
116 public boolean visitDirectory(Resource resource) {
117 return true;
118 }
119 }).traverse(root);
120
121 return result.build();
122 }
123
124 /**
125 * Collect all resources matching provided predicate starting at the specified path.
126 */
127 default Stream<Resource> find(String rootPath, Predicate<Resource> filter) {
128
129 if (!hasPath(rootPath)) {
130 return Stream.empty();
131 }
132
133 return find(getByPath(rootPath), filter);
134 }
135
136 /**
137 * Thrown when a given path can't be found.
138 */
139 class ResourceNotFoundException extends RuntimeException {
140 public ResourceNotFoundException(ResourceOrigin origin, String path) {
141 super("No resource found for path " + path + " in origin " + origin.getName());
142 }
143 }
144
145 }