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Java > Open Source Codes > org > displaytag > tags > TableTagExtraInfo


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 JavaDoc;
15 import java.util.Arrays JavaDoc;
16 import java.util.List JavaDoc;
17
18 import javax.servlet.jsp.tagext.TagAttributeInfo JavaDoc;
19 import javax.servlet.jsp.tagext.TagData JavaDoc;
20 import javax.servlet.jsp.tagext.TagExtraInfo JavaDoc;
21 import javax.servlet.jsp.tagext.VariableInfo JavaDoc;
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: 763 $ ($Author: fgiust $)
32  */
33 public class TableTagExtraInfo extends TagExtraInfo JavaDoc
34 {
35
36     /**
37      * Suffix added to id for saving row number in pagecontext.
38      */
39     public static final String JavaDoc ROWNUM_SUFFIX = "_rowNum"; //$NON-NLS-1$
40
41     /**
42      * Java keywords.
43      */
44     private static final String JavaDoc[] 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 JavaDoc[] getVariableInfo(TagData JavaDoc data)
106     {
107         List JavaDoc variables = new ArrayList JavaDoc(2);
108
109         Object JavaDoc 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 JavaDoc 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 JavaDoc(tagId, Object JavaDoc.class.getName(), true, VariableInfo.NESTED));
127                 // current row number
128 variables.add(new VariableInfo JavaDoc(
129                     tagId + ROWNUM_SUFFIX,
130                     Integer JavaDoc.class.getName(),
131                     true,
132                     VariableInfo.NESTED));
133             }
134         }
135
136         return (VariableInfo JavaDoc[]) variables.toArray(new VariableInfo JavaDoc[]{});
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 JavaDoc 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 }
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