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 * https://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.Strings;
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
35 /** Constant for the wildcard node name. */
36 private static final String WILDCARD = "*";
37
38 /** Stores the parent node pointer. */
39 private final ConfigurationNodePointer<T> parentPointer;
40
41 /** A list with the names of the managed attributes. */
42 private final List<String> attributeNames;
43
44 /**
45 * Creates a new instance of {@code ConfigurationNodeIteratorAttribute}.
46 *
47 * @param parent the parent node pointer
48 * @param qName the name of the selected attribute
49 */
50 public ConfigurationNodeIteratorAttribute(final ConfigurationNodePointer<T> parent, final QName qName) {
51 super(parent, false);
52 parentPointer = parent;
53 attributeNames = createAttributeDataList(parent, qName);
54 }
55
56 /**
57 * Helper method for checking whether an attribute is defined and adding it to the list of attributes to iterate over.
58 *
59 * @param parent the parent node pointer
60 * @param result the result list
61 * @param name the name of the current attribute
62 */
63 private void addAttributeData(final ConfigurationNodePointer<T> parent, final List<String> result, final String name) {
64 if (parent.getNodeHandler().getAttributeValue(parent.getConfigurationNode(), name) != null) {
65 result.add(name);
66 }
67 }
68
69 /**
70 * Determines which attributes are selected based on the passed in node name.
71 *
72 * @param parent the parent node pointer
73 * @param qName the name of the selected attribute
74 * @return a list with the selected attributes
75 */
76 private List<String> createAttributeDataList(final ConfigurationNodePointer<T> parent, final QName qName) {
77 final List<String> result = new ArrayList<>();
78 if (!WILDCARD.equals(qName.getName())) {
79 addAttributeData(parent, result, qualifiedName(qName));
80 } else {
81 final Set<String> names = new LinkedHashSet<>(parent.getNodeHandler().getAttributes(parent.getConfigurationNode()));
82 final String prefix = qName.getPrefix() != null ? prefixName(qName.getPrefix(), null) : null;
83 names.forEach(n -> {
84 if (prefix == null || Strings.CS.startsWith(n, prefix)) {
85 addAttributeData(parent, result, n);
86 }
87 });
88 }
89
90 return result;
91 }
92
93 /**
94 * Creates a pointer for the node at the specified position.
95 *
96 * @param position the desired position
97 * @return a pointer for the attribute at this position
98 */
99 @Override
100 protected NodePointer createNodePointer(final int position) {
101 return new ConfigurationAttributePointer<>(parentPointer, attributeNames.get(position));
102 }
103
104 /**
105 * Returns the size of the managed iteration.
106 *
107 * @return the iteration size
108 */
109 @Override
110 protected int size() {
111 return attributeNames.size();
112 }
113 }