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Java > Open Source Codes > com > jcorporate > expresso > services > taglib > ButtonParams


1 package com.jcorporate.expresso.services.taglib;
2
3 /* ====================================================================
4  * The Jcorporate Apache Style Software License, Version 1.2 05-07-2002
5  *
6  * Copyright (c) 1995-2003 Jcorporate Ltd. All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  * notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  * notice, this list of conditions and the following disclaimer in
17  * the documentation and/or other materials provided with the
18  * distribution.
19  *
20  * 3. The end-user documentation included with the redistribution,
21  * if any, must include the following acknowledgment:
22  * "This product includes software developed by Jcorporate Ltd.
23  * (http://www.jcorporate.com/)."
24  * Alternately, this acknowledgment may appear in the software itself,
25  * if and wherever such third-party acknowledgments normally appear.
26  *
27  * 4. "Jcorporate" and product names such as "Expresso" must
28  * not be used to endorse or promote products derived from this
29  * software without prior written permission. For written permission,
30  * please contact info@jcorporate.com.
31  *
32  * 5. Products derived from this software may not be called "Expresso",
33  * or other Jcorporate product names; nor may "Expresso" or other
34  * Jcorporate product names appear in their name, without prior
35  * written permission of Jcorporate Ltd.
36  *
37  * 6. No product derived from this software may compete in the same
38  * market space, i.e. framework, without prior written permission
39  * of Jcorporate Ltd. For written permission, please contact
40  * partners@jcorporate.com.
41  *
42  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
43  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
44  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
45  * DISCLAIMED. IN NO EVENT SHALL JCORPORATE LTD OR ITS CONTRIBUTORS
46  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
47  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
48  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
49  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
50  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
51  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
52  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53  * SUCH DAMAGE.
54  * ====================================================================
55  *
56  * This software consists of voluntary contributions made by many
57  * individuals on behalf of the Jcorporate Ltd. Contributions back
58  * to the project(s) are encouraged when you make modifications.
59  * Please send them to support@jcorporate.com. For more information
60  * on Jcorporate Ltd. and its products, please see
61  * <http://www.jcorporate.com/>.
62  *
63  * Portions of this software are based upon other open source
64  * products and are subject to their respective licenses.
65  */
66
67
68 import com.jcorporate.expresso.core.controller.Transition;
69 import com.jcorporate.expresso.core.misc.URLUTF8Encoder;
70 import com.jcorporate.expresso.kernel.util.FastStringBuffer;
71 import org.apache.log4j.Logger;
72
73 import javax.servlet.jsp.JspException JavaDoc;
74 import javax.servlet.jsp.tagext.TagSupport JavaDoc;
75 import java.io.IOException JavaDoc;
76
77
78 /**
79  * Use ButtonParamsTag right after putting a button on a form that maps
80  * to a particular Transition. The ButtomParams tag will add a hidden
81  * form field that will contain all the appropriate parameters associated
82  * with the Transition. The only supported attribute is 'value', there is
83  * no default given, since it is critical that it maps to an existing transition.
84  * <p>value parameter should map to a Transition. Example:
85  * <blockquote><pre>
86  * <expresso-el:params value="${controllerResponse.namedTransitions['submit']}"/>
87  * </pre><blockquote>
88  * </p>
89  *
90  * @author Michael Rimov
91  * @version $Revision: 1.6 $ on $Date: 2004/11/17 20:48:21 $
92  */
93
94 public class ButtonParams extends TagSupport JavaDoc {
95
96     private static final Logger log = Logger.getLogger(ButtonParams.class);
97
98     /**
99      * JSTL EL expression
100      */
101     private String JavaDoc value;
102
103
104     /**
105      * Default constructor
106      */
107     public ButtonParams() {
108     }
109
110     /**
111      * Get the JSTL expression for value.
112      *
113      * @return java.lang.String
114      */
115     public String JavaDoc getValue() {
116         return value;
117     }
118
119     /**
120      * Sets the value JSTL expression
121      *
122      * @param value
123      */
124     public void setValue(String JavaDoc value) {
125         this.value = value;
126     }
127
128     /**
129      * Does the actual grunt work.
130      *
131      * @return EVAL_PAGE
132      */
133     public int doEndTag() throws javax.servlet.jsp.JspException JavaDoc {
134         ELTagSupport support = ELTagSupport.getInstance();
135         Transition result = (Transition) support.evaluate("value", this.getValue(),
136                 Transition.class,
137                 this, this.pageContext);
138
139         if (result == null) {
140             throw new JspException JavaDoc("Unable to locate transition for expression: " + this.getValue());
141         }
142
143         FastStringBuffer fsb = FastStringBuffer.getInstance();
144         String JavaDoc writeValue;
145         try {
146             fsb.append("<input type=hidden name=\"");
147             fsb.append(result.getName());
148             fsb.append("_params\" value=\"");
149             fsb.append(URLUTF8Encoder.encode(result.getParamString(true)));
150             fsb.append("\">\n");
151             fsb.append("<input type=hidden name=\"");
152             fsb.append(result.getName());
153             fsb.append("_encoding\" value=\"u\">");
154         } finally {
155             writeValue = fsb.toString();
156             fsb.release();
157         }
158
159         try {
160             this.pageContext.getOut().write(writeValue);
161         } catch (IOException JavaDoc ex1) {
162             log.error("Error writing output", ex1);
163             throw new JspException JavaDoc("I/O error");
164         }
165
166         return EVAL_PAGE;
167     }
168
169 }
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