1 /**
2 * Licensed under the Artistic License; you may not use this file
3 * except in compliance with the License.
4 * You may obtain a copy of the License at
5 *
6 * http://displaytag.sourceforge.net/license.html
7 *
8 * THIS PACKAGE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR
9 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
10 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
11 */
12 package org.displaytag.tags;
13
14 import java.util.ArrayList;
15 import java.util.Arrays;
16 import java.util.List;
17
18 import javax.servlet.jsp.tagext.TagAttributeInfo;
19 import javax.servlet.jsp.tagext.TagData;
20 import javax.servlet.jsp.tagext.TagExtraInfo;
21 import javax.servlet.jsp.tagext.VariableInfo;
22
23
24 /**
25 * TEI for TableTag, defines 3 variables.
26 * <ul>
27 * <li>table uid = object contained in row</li>
28 * <li>table uid + ROWNUM_SUFFIX = row number</li>
29 * </ul>
30 * @author Fabrizio Giustina
31 * @version $Revision: 1081 $ ($Author: fgiust $)
32 */
33 public class TableTagExtraInfo extends TagExtraInfo
34 {
35
36 /**
37 * Suffix added to id for saving row number in pagecontext.
38 */
39 public static final String ROWNUM_SUFFIX = "_rowNum"; //$NON-NLS-1$
40
41 /**
42 * Java keywords.
43 */
44 private static final String[] KEYWORDS = {"abstract", //$NON-NLS-1$
45 "assert", //$NON-NLS-1$
46 "boolean", //$NON-NLS-1$
47 "break", //$NON-NLS-1$
48 "byte", //$NON-NLS-1$
49 "case", //$NON-NLS-1$
50 "catch", //$NON-NLS-1$
51 "char", //$NON-NLS-1$
52 "class", //$NON-NLS-1$
53 "const", //$NON-NLS-1$
54 "continue", //$NON-NLS-1$
55 "default", //$NON-NLS-1$
56 "do", //$NON-NLS-1$
57 "double", //$NON-NLS-1$
58 "else", //$NON-NLS-1$
59 "enum", //$NON-NLS-1$
60 "extends", //$NON-NLS-1$
61 "false", //$NON-NLS-1$
62 "final", //$NON-NLS-1$
63 "finally", //$NON-NLS-1$
64 "float", //$NON-NLS-1$
65 "for", //$NON-NLS-1$
66 "goto", //$NON-NLS-1$
67 "if", //$NON-NLS-1$
68 "implements", //$NON-NLS-1$
69 "import", //$NON-NLS-1$
70 "instanceof", //$NON-NLS-1$
71 "int", //$NON-NLS-1$
72 "interface", //$NON-NLS-1$
73 "long", //$NON-NLS-1$
74 "native", //$NON-NLS-1$
75 "new", //$NON-NLS-1$
76 "null", //$NON-NLS-1$
77 "package", //$NON-NLS-1$
78 "private", //$NON-NLS-1$
79 "protected", //$NON-NLS-1$
80 "public", //$NON-NLS-1$
81 "return", //$NON-NLS-1$
82 "short", //$NON-NLS-1$
83 "static", //$NON-NLS-1$
84 "strictfp", //$NON-NLS-1$
85 "super", //$NON-NLS-1$
86 "switch", //$NON-NLS-1$
87 "synchronized", //$NON-NLS-1$
88 "this", //$NON-NLS-1$
89 "throw", //$NON-NLS-1$
90 "throws", //$NON-NLS-1$
91 "transient", //$NON-NLS-1$
92 "true", //$NON-NLS-1$
93 "try", //$NON-NLS-1$
94 "void", //$NON-NLS-1$
95 "volatile", //$NON-NLS-1$
96 "while"}; //$NON-NLS-1$
97
98 /**
99 * Variables TableTag makes available in the pageContext.
100 * @param data TagData
101 * @return VariableInfo[]
102 * @see javax.servlet.jsp.tagext.TagData
103 * @see javax.servlet.jsp.tagext.VariableInfo
104 */
105 public VariableInfo[] getVariableInfo(TagData data)
106 {
107 List variables = new ArrayList(2);
108
109 Object idObj = data.getAttribute(TagAttributeInfo.ID);
110
111 // handle both the id and uid attributes
112 if (idObj == null)
113 {
114 idObj = data.getAttribute("uid"); //$NON-NLS-1$
115 }
116
117 // avoid errors, but "id" and "id_rownum" will not be defined
118 if (idObj != TagData.REQUEST_TIME_VALUE && idObj != null)
119 {
120 String tagId = idObj.toString();
121
122 // don't try to add variables if id is not a valid java identifier.
123 if (isJavaId(tagId))
124 {
125 // current row
126 variables.add(new VariableInfo(tagId, Object.class.getName(), true, VariableInfo.NESTED));
127 // current row number
128 variables.add(new VariableInfo(
129 tagId + ROWNUM_SUFFIX,
130 Integer.class.getName(),
131 true,
132 VariableInfo.NESTED));
133 }
134 }
135
136 return (VariableInfo[]) variables.toArray(new VariableInfo[]{});
137 }
138
139 /**
140 * isJavaId Returns true if the name is a valid java identifier.
141 * @param id to check
142 * @return boolean true/false
143 */
144 public static boolean isJavaId(String id)
145 {
146 if (id == null
147 || id.length() == 0
148 || Arrays.binarySearch(KEYWORDS, id) >= 0
149 || !Character.isJavaIdentifierStart(id.charAt(0)))
150 {
151 return false;
152 }
153
154 for (int j = 1; j < id.length(); j++)
155 {
156 if (!Character.isJavaIdentifierPart(id.charAt(j)))
157 {
158 return false;
159 }
160 }
161 return true;
162 }
163
164 }