1 /*
2 * Grapht, an open source dependency injector.
3 * Copyright 2014-2015 various contributors (see CONTRIBUTORS.txt)
4 * Copyright 2010-2014 Regents of the University of Minnesota
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU Lesser General Public License as
8 * published by the Free Software Foundation; either version 2.1 of the
9 * License, or (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
13 * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
14 * details.
15 *
16 * You should have received a copy of the GNU General Public License along with
17 * this program; if not, write to the Free Software Foundation, Inc., 51
18 * Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
19 */
20 package org.grouplens.grapht.context;
21
22 import org.apache.commons.lang3.tuple.Pair;
23 import org.grouplens.grapht.reflect.InjectionPoint;
24 import org.grouplens.grapht.reflect.Satisfaction;
25
26 import javax.inject.Qualifier;
27 import java.io.Serializable;
28
29 /**
30 * <p>
31 * ContextElementMatcher represents a "pattern" that can match an element within the
32 * dependency context created as a Resolver follows a dependency hierarchy. The
33 * dependency context is an ordered list of satisfactions and the qualifiers of the desires they satisfy.
34 * The first satisfaction is the root satisfaction, a {@code null} satisfaction of type {@code void}.
35 * <p>
36 * ContextMatchers can match or apply to these nodes and {@link Qualifier}s
37 * within a dependency context. As an example, the reflection based
38 * ContextElementMatcher matches nodes that are sub-types of the type the matcher was
39 * configured with.
40 *
41 * @author <a href="http://grouplens.org">GroupLens Research</a>
42 */
43 public interface ContextElementMatcher extends Serializable {
44 /**
45 * Return true if this ContextElementMatcher matches or applies to the given Satisfaction and
46 * Qualifier.
47 *
48 * @param n The node and attributes in the current dependency context
49 * @return A match if this matcher matches the provided node label, or {@code false} if there is
50 * no match.
51 */
52 MatchElement apply(Pair<Satisfaction, InjectionPoint> n);
53 }