1 ////////////////////////////////////////////////////////////////////////////////
2 // checkstyle: Checks Java source code for adherence to a set of rules.
3 // Copyright (C) 2001-2019 the original author or authors.
4 //
5 // This library is free software; you can redistribute it and/or
6 // modify it under the terms of the GNU Lesser General Public
7 // License as published by the Free Software Foundation; either
8 // version 2.1 of the License, or (at your option) any later version.
9 //
10 // This library is distributed in the hope that it will be useful,
11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 // Lesser General Public License for more details.
14 //
15 // You should have received a copy of the GNU Lesser General Public
16 // License along with this library; if not, write to the Free Software
17 // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18 ////////////////////////////////////////////////////////////////////////////////
19
20 package com.puppycrawl.tools.checkstyle.xpath;
21
22 import com.puppycrawl.tools.checkstyle.api.DetailAST;
23 import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
24 import com.puppycrawl.tools.checkstyle.utils.XpathUtil;
25 import net.sf.saxon.om.AxisInfo;
26 import net.sf.saxon.om.NodeInfo;
27 import net.sf.saxon.tree.iter.ArrayIterator;
28 import net.sf.saxon.tree.iter.AxisIterator;
29 import net.sf.saxon.tree.iter.EmptyIterator;
30 import net.sf.saxon.tree.iter.SingleNodeIterator;
31 import net.sf.saxon.tree.util.Navigator;
32 import net.sf.saxon.type.Type;
33
34 /**
35 * Represents element node of Xpath-tree.
36 *
37 */
38 public class ElementNode extends AbstractNode {
39
40 /** String literal for text attribute. */
41 private static final String TEXT_ATTRIBUTE_NAME = "text";
42
43 /** Constant for optimization. */
44 private static final AbstractNode[] EMPTY_ABSTRACT_NODE_ARRAY = new AbstractNode[0];
45
46 /** The root node. */
47 private final AbstractNode root;
48
49 /** The parent of the current node. */
50 private final AbstractNode parent;
51
52 /** The ast node. */
53 private final DetailAST detailAst;
54
55 /** Represents text of the DetailAST. */
56 private final String text;
57
58 /** The text attribute node. */
59 private AttributeNode attributeNode;
60
61 /**
62 * Creates a new {@code ElementNode} instance.
63 *
64 * @param root {@code Node} root of the tree
65 * @param parent {@code Node} parent of the current node
66 * @param detailAst reference to {@code DetailAST}
67 */
68 public ElementNode(AbstractNode root, AbstractNode parent, DetailAST detailAst) {
69 super(root.getTreeInfo());
70 this.parent = parent;
71 this.root = root;
72 this.detailAst = detailAst;
73 text = TokenUtil.getTokenName(detailAst.getType());
74 createTextAttribute();
75 createChildren();
76 }
77
78 /**
79 * Iterates children of the current node and
80 * recursively creates new Xpath-nodes.
81 */
82 private void createChildren() {
83 DetailAST currentChild = detailAst.getFirstChild();
84 while (currentChild != null) {
85 final AbstractNode child = new ElementNode(root, this, currentChild);
86 addChild(child);
87 currentChild = currentChild.getNextSibling();
88 }
89 }
90
91 /**
92 * Returns attribute value. Throws {@code UnsupportedOperationException} in case,
93 * when name of the attribute is not equal to 'text'.
94 * @param namespace namespace
95 * @param localPart actual name of the attribute
96 * @return attribute value
97 */
98 @Override
99 public String getAttributeValue(String namespace, String localPart) {
100 final String result;
101 if (TEXT_ATTRIBUTE_NAME.equals(localPart)) {
102 if (attributeNode == null) {
103 result = null;
104 }
105 else {
106 result = attributeNode.getStringValue();
107 }
108 }
109 else {
110 result = null;
111 }
112 return result;
113 }
114
115 /**
116 * Returns local part.
117 * @return local part
118 */
119 // -@cs[SimpleAccessorNameNotation] Overrides method from the base class.
120 // Issue: https://github.com/sevntu-checkstyle/sevntu.checkstyle/issues/166
121 @Override
122 public String getLocalPart() {
123 return text;
124 }
125
126 /**
127 * Returns type of the node.
128 * @return node kind
129 */
130 @Override
131 public int getNodeKind() {
132 return Type.ELEMENT;
133 }
134
135 /**
136 * Returns parent.
137 * @return parent
138 */
139 @Override
140 public NodeInfo getParent() {
141 return parent;
142 }
143
144 /**
145 * Returns root.
146 * @return root
147 */
148 @Override
149 public NodeInfo getRoot() {
150 return root;
151 }
152
153 /**
154 * Returns string value.
155 * @return string value
156 */
157 // -@cs[SimpleAccessorNameNotation] Overrides method from the base class.
158 // Issue: https://github.com/sevntu-checkstyle/sevntu.checkstyle/issues/166
159 @Override
160 public String getStringValue() {
161 return text;
162 }
163
164 /**
165 * Determines axis iteration algorithm. Throws {@code UnsupportedOperationException} in case,
166 * when there is no axis iterator for given axisNumber.
167 *
168 * @param axisNumber element from {@code AxisInfo}
169 * @return {@code AxisIterator} object
170 */
171 @Override
172 public AxisIterator iterateAxis(byte axisNumber) {
173 final AxisIterator result;
174 switch (axisNumber) {
175 case AxisInfo.ANCESTOR:
176 try (AxisIterator iterator = new Navigator.AncestorEnumeration(this, false)) {
177 result = iterator;
178 }
179 break;
180 case AxisInfo.ANCESTOR_OR_SELF:
181 try (AxisIterator iterator = new Navigator.AncestorEnumeration(this, true)) {
182 result = iterator;
183 }
184 break;
185 case AxisInfo.ATTRIBUTE:
186 try (AxisIterator iterator = SingleNodeIterator.makeIterator(attributeNode)) {
187 result = iterator;
188 }
189 break;
190 case AxisInfo.CHILD:
191 if (hasChildNodes()) {
192 try (AxisIterator iterator = new ArrayIterator.OfNodes(
193 getChildren().toArray(EMPTY_ABSTRACT_NODE_ARRAY))) {
194 result = iterator;
195 }
196 }
197 else {
198 result = EmptyIterator.OfNodes.THE_INSTANCE;
199 }
200 break;
201 case AxisInfo.DESCENDANT:
202 if (hasChildNodes()) {
203 try (AxisIterator iterator =
204 new Navigator.DescendantEnumeration(this, false, true)) {
205 result = iterator;
206 }
207 }
208 else {
209 result = EmptyIterator.OfNodes.THE_INSTANCE;
210 }
211 break;
212 case AxisInfo.DESCENDANT_OR_SELF:
213 try (AxisIterator iterator =
214 new Navigator.DescendantEnumeration(this, true, true)) {
215 result = iterator;
216 }
217 break;
218 case AxisInfo.PARENT:
219 try (AxisIterator iterator = SingleNodeIterator.makeIterator(parent)) {
220 result = iterator;
221 }
222 break;
223 case AxisInfo.SELF:
224 try (AxisIterator iterator = SingleNodeIterator.makeIterator(this)) {
225 result = iterator;
226 }
227 break;
228 default:
229 throw throwUnsupportedOperationException();
230 }
231 return result;
232 }
233
234 /**
235 * Returns line number.
236 * @return line number
237 */
238 @Override
239 public int getLineNumber() {
240 return detailAst.getLineNo();
241 }
242
243 /**
244 * Returns column number.
245 * @return column number
246 */
247 @Override
248 public int getColumnNumber() {
249 return detailAst.getColumnNo();
250 }
251
252 /**
253 * Getter method for token type.
254 * @return token type
255 */
256 @Override
257 public int getTokenType() {
258 return detailAst.getType();
259 }
260
261 /**
262 * Returns underlying node.
263 * @return underlying node
264 */
265 // -@cs[SimpleAccessorNameNotation] Overrides method from the base class.
266 // Issue: https://github.com/sevntu-checkstyle/sevntu.checkstyle/issues/166
267 @Override
268 public DetailAST getUnderlyingNode() {
269 return detailAst;
270 }
271
272 /**
273 * Checks if token type supports {@code @text} attribute,
274 * extracts its value, creates {@code AttributeNode} object and returns it.
275 * Value can be accessed using {@code @text} attribute.
276 */
277 private void createTextAttribute() {
278 AttributeNode attribute = null;
279 if (XpathUtil.supportsTextAttribute(detailAst)) {
280 attribute = new AttributeNode(TEXT_ATTRIBUTE_NAME,
281 XpathUtil.getTextAttributeValue(detailAst));
282 }
283 attributeNode = attribute;
284 }
285
286 /**
287 * Returns UnsupportedOperationException exception.
288 * @return UnsupportedOperationException exception
289 */
290 private static UnsupportedOperationException throwUnsupportedOperationException() {
291 return new UnsupportedOperationException("Operation is not supported");
292 }
293
294 }