Source code: info/crossbar/view/taglib/DatagridTag.java
1 /*
2 * @(#)DatagridTag.java $Revision: 1.3 $ $Date: 2003/06/04 04:55:20 $
3 *
4 * Copyright 2002 by Daniel Kehoe <kehoe@fortuity.com>
5 * All Rights Reserved
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28 package info.crossbar.view.taglib;
29
30 import java.util.*;
31 import java.util.logging.Logger;
32
33 import java.io.*;
34
35 import javax.servlet.http.HttpServletRequest;
36 import javax.servlet.http.HttpServletResponse;
37 import javax.servlet.ServletException;
38
39 import javax.servlet.jsp.*;
40 import javax.servlet.jsp.tagext.*;
41
42 import java.sql.SQLException;
43
44 import sun.jdbc.rowset.CachedRowSet;
45
46 import org.apache.taglibs.standard.lang.support.*;
47
48 import info.crossbar.view.formatter.FormatterAbstraction;
49
50
51 /**
52 * DatagridTag class for use by <a href="http://www.crossbar.info/">Crossbar</a>
53 *
54 * @author Daniel Kehoe, <a href="http://www.fortuity.com/">Fortuity Consulting</a>
55 * @created January 23, 2002
56 * @version <a href="http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/crossbar/crossbar-sitemap/src/java/info/crossbar/view/taglib/DatagridTag.java">View source, revision history</a>
57 * $Revision: 1.3 $ $Date: 2003/06/04 04:55:20 $
58 * <p>
59 * DESCRIPTION:
60 * The DatagridTag class takes tabular data obtained from a database
61 * and outputs a table using markup (such as HTML) provided by a Formatter.
62 */
63 public class DatagridTag extends TagSupport {
64
65 /**
66 * Set up logging.
67 */
68 private static Logger log = Logger.getLogger(DatagridTag.class.getName());
69
70 private CachedRowSet table = null;
71 private String modelReference = null;
72 private String formatterName = null;
73 private String headerstyle = null;
74 private String bodystyle = null;
75 private String footerstyle = null;
76
77 /**
78 * Method accepts a CachedRowSet. The tabular data can be the result
79 * set from an SQL query, data for a form (field names and default values), a
80 * series of messages, or any other data set organized as fields and rows.
81 *
82 * @param table a CachedRowSet object
83 */
84 public void setModelReference(String modelReference) {
85 this.modelReference = modelReference;
86 }
87
88 /**
89 * A Model can recommend how the tabular data should be displayed (for example,
90 * as a form or messages, or as a table of multiple rows).
91 *
92 * @param formatter a formatter class such as "info.crossbar.view.formatter.html.FormatterForForm"
93 */
94 public void setFormatter(String formatter) {
95 if (formatter != null) {
96 this.formatterName = formatter;
97 } else log.fine("formatterName is null");
98 }
99
100
101 /**
102 * Accepts a String from a jsp page specifying a CSS style for a table
103 * header.
104 *
105 * @param align a String such as "tableheader1"
106 */
107 public void setHeaderstyle(String headerstyle) {
108 this.headerstyle = headerstyle;
109 }
110
111 /**
112 * Accepts a String from a jsp page specifying a CSS style for table
113 * body cells.
114 *
115 * @param align a String such as "tablebody"
116 */
117 public void setBodystyle(String bodystyle) {
118 this.bodystyle = bodystyle;
119 }
120
121 /**
122 * Accepts a String from a jsp page specifying a CSS style for a table
123 * footer.
124 *
125 * @param align a String such as "tablefooter1"
126 */
127 public void setFooterstyle(String footerstyle) {
128 this.footerstyle = footerstyle;
129 }
130
131 /**
132 * Process the start tag for this instance. See the JSP API specification for details.
133 *
134 * @return int (see the spec)
135 */
136 public int doStartTag() {
137 log.finest("ENTRY trying to output table using model \""
138 + this.modelReference + "\" and formatter \"" + this.formatterName + "\"");
139 try {
140 this.table = (CachedRowSet) ExpressionEvaluatorManager.evaluate("modelReference",
141 this.modelReference, CachedRowSet.class, this, pageContext);
142 JspWriter out = pageContext.getOut();
143 out.print(markup());
144 } catch (JspException jspe) {
145 log.warning(jspe.getMessage());
146 } catch (IOException ioe) {
147 log.warning(ioe.getMessage());
148 } catch (ServletException se) {
149 log.warning(se.getMessage());
150 }
151 log.finest("RETURN tag is done outputting markup and content");
152 return (SKIP_BODY);
153 }
154
155 /**
156 * Process the start tag for this instance. See the JSP API specification for details.
157 *
158 * @return String tabular data with HTML markup
159 */
160 public String markup()
161 throws ServletException {
162 log.finest("ENTRY trying to output table");
163 StringBuffer buffer = new StringBuffer("");
164 if (this.table == null) {
165 // just in case there's a null table:
166 buffer.append("<!-- table is null -->");
167 log.fine("table is null");
168 } else {
169 if (this.formatterName == null) {
170 try {
171 // look for a formatter name hidden in the table title:
172 String title = table.getTableName();
173 if ("TEXT".equals(title.toUpperCase())) {
174 this.formatterName = "info.crossbar.view.formatter.html.FormatterForText";
175 } else if ("MESSAGES".equals(title.toUpperCase())) {
176 this.formatterName = "info.crossbar.view.formatter.html.FormatterForMessages";
177 } else if ("TABLE".equals(title.toUpperCase())) {
178 this.formatterName = "info.crossbar.view.formatter.html.FormatterForTable";
179 } else this.formatterName = "info.crossbar.view.formatter.html.FormatterForTable";
180 } catch (SQLException e) {
181 log.finest("could not get table title!");
182 }
183 } else if ("TEXT".equals(this.formatterName)) {
184 this.formatterName = "info.crossbar.view.formatter.html.FormatterForText";
185 } else if ("MESSAGES".equals(this.formatterName)) {
186 this.formatterName = "info.crossbar.view.formatter.html.FormatterForMessages";
187 } else if ("TABLE".equals(this.formatterName)) {
188 this.formatterName = "info.crossbar.view.formatter.html.FormatterForTable";
189 } // else just use what was given!
190 log.finest("using formatter \"" + this.formatterName + "\"");
191 /*
192 * We load a class dynamically and
193 * instantiate an object based on a parameter passed from the jsp page.
194 * We have an interface named "FormatterAbstraction" which describes possible methods.
195 * Developers can implement FormatterAbstraction and make any new kind of
196 * Formatter which is used to mix markup and content for output.
197 */
198 // the FormatterAbstraction class is an interface that defines a "markup" method:
199 FormatterAbstraction formatter = null;
200 try {
201 // instantiate the Formatter:
202 formatter = (FormatterAbstraction)Class.forName(this.formatterName, true, DatagridTag.class.getClassLoader()).newInstance();
203 // make the formatter do its work:
204 buffer.append(formatter.markup((HttpServletRequest)pageContext.getRequest(),
205 this.table, this.headerstyle, this.bodystyle, this.footerstyle));
206 } catch (ClassNotFoundException cnfe) {
207 String msg = ("The " + DatagridTag.class.getName() + " class could not "
208 + "find a Formatter: "
209 + cnfe.getMessage());
210 log.fine(msg);
211 throw new ServletException(msg);
212 } catch (InstantiationException ie) {
213 String msg = ("The " + DatagridTag.class.getName() + " class could not "
214 + "instantiate a Formatter: "
215 + ie.getMessage());
216 log.fine(msg);
217 throw new ServletException(msg);
218 } catch (IllegalAccessException iae) {
219 String msg = ("The " + DatagridTag.class.getName() + " class could not "
220 + "access a Formatter: "
221 + iae.getMessage());
222 log.fine(msg);
223 throw new ServletException(msg);
224 }
225 }
226 log.finest("RETURN done marking up content");
227 return buffer.toString();
228 }
229 }
230