1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.configuration2.tree.xpath;
18
19 import java.util.ArrayList;
20 import java.util.LinkedHashSet;
21 import java.util.List;
22 import java.util.Set;
23
24 import org.apache.commons.jxpath.ri.QName;
25 import org.apache.commons.jxpath.ri.model.NodePointer;
26 import org.apache.commons.lang3.StringUtils;
27
28 /**
29 * A specialized node iterator implementation that deals with attribute nodes.
30 *
31 * @param <T> the type of the nodes this iterator deals with
32 */
33 final class ConfigurationNodeIteratorAttribute<T> extends AbstractConfigurationNodeIterator<T> {
34 /** Constant for the wildcard node name. */
35 private static final String WILDCARD = "*";
36
37 /** Stores the parent node pointer. */
38 private final ConfigurationNodePointer<T> parentPointer;
39
40 /** A list with the names of the managed attributes. */
41 private final List<String> attributeNames;
42
43 /**
44 * Creates a new instance of {@code ConfigurationNodeIteratorAttribute}.
45 *
46 * @param parent the parent node pointer
47 * @param name the name of the selected attribute
48 */
49 public ConfigurationNodeIteratorAttribute(final ConfigurationNodePointer<T> parent, final QName name) {
50 super(parent, false);
51 parentPointer = parent;
52 attributeNames = createAttributeDataList(parent, name);
53 }
54
55 /**
56 * Creates a pointer for the node at the specified position.
57 *
58 * @param position the desired position
59 * @return a pointer for the attribute at this position
60 */
61 @Override
62 protected NodePointer createNodePointer(final int position) {
63 return new ConfigurationAttributePointer<>(parentPointer, attributeNames.get(position));
64 }
65
66 /**
67 * Returns the size of the managed iteration.
68 *
69 * @return the iteration size
70 */
71 @Override
72 protected int size() {
73 return attributeNames.size();
74 }
75
76 /**
77 * Determines which attributes are selected based on the passed in node name.
78 *
79 * @param parent the parent node pointer
80 * @param name the name of the selected attribute
81 * @return a list with the selected attributes
82 */
83 private List<String> createAttributeDataList(final ConfigurationNodePointer<T> parent, final QName name) {
84 final List<String> result = new ArrayList<>();
85 if (!WILDCARD.equals(name.getName())) {
86 addAttributeData(parent, result, qualifiedName(name));
87 } else {
88 final Set<String> names = new LinkedHashSet<>(parent.getNodeHandler().getAttributes(parent.getConfigurationNode()));
89 final String prefix = name.getPrefix() != null ? prefixName(name.getPrefix(), null) : null;
90 names.forEach(n -> {
91 if (prefix == null || StringUtils.startsWith(n, prefix)) {
92 addAttributeData(parent, result, n);
93 }
94 });
95 }
96
97 return result;
98 }
99
100 /**
101 * Helper method for checking whether an attribute is defined and adding it to the list of attributes to iterate over.
102 *
103 * @param parent the parent node pointer
104 * @param result the result list
105 * @param name the name of the current attribute
106 */
107 private void addAttributeData(final ConfigurationNodePointer<T> parent, final List<String> result, final String name) {
108 if (parent.getNodeHandler().getAttributeValue(parent.getConfigurationNode(), name) != null) {
109 result.add(name);
110 }
111 }
112 }