DbBodyTag


1   /*
2    * $Header: /cvsroot/jdbforms/dbforms/src/org/dbforms/taglib/DbBodyTag.java,v 1.28 2004/10/26 19:46:06 hkollmann Exp $
3    * $Revision: 1.28 $
4    * $Date: 2004/10/26 19:46:06 $
5    *
6    * DbForms - a Rapid Application Development Framework
7    * Copyright (C) 2001 Joachim Peer <joepeer@excite.com>
8    *
9    * This library is free software; you can redistribute it and/or
10   * modify it under the terms of the GNU Lesser General Public
11   * License as published by the Free Software Foundation; either
12   * version 2.1 of the License, or (at your option) any later version.
13   *
14   * This library is distributed in the hope that it will be useful,
15   * but WITHOUT ANY WARRANTY; without even the implied warranty of
16   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
17   * Lesser General Public License for more details.
18   *
19   * You should have received a copy of the GNU Lesser General Public
20   * License along with this library; if not, write to the Free Software
21   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
22   */
23  
24  package org.dbforms.taglib;
25  
26  import org.dbforms.config.ResultSetVector;
27  
28  import org.dbforms.util.Util;
29  
30  import java.io.UnsupportedEncodingException  ;
31  
32  import java.util.Map  ;
33  
34  import javax.servlet.jsp.JspException  ;
35  
36  
37  
38  /**
39   * <p>
40   * this tag renders a Body-tag. it is supposed to be nested within a DbFormTag.
41   * because this tag is nested within a DbFormTag it is invoked every time the
42   * parent dbFormTag gets evaluated, AND it gets rendered in every
43   * evalation-loop (if there exists data to be rendered)
44   * </p>
45   *
46   * @author Joachim Peer
47   */
48  public class DbBodyTag extends DbBaseHandlerTag
49     implements javax.servlet.jsp.tagext.TryCatchFinally   {
50     private String   allowNew = "true";
51  
52     /**
53      * DOCUMENT ME!
54      *
55      * @param allowNew DOCUMENT ME!
56      */
57     public void setAllowNew(String   allowNew) {
58        this.allowNew = allowNew;
59     }
60  
61  
62     /**
63      * DOCUMENT ME!
64      *
65      * @return DOCUMENT ME!
66      */
67     public String   getAllowNew() {
68        return allowNew;
69     }
70  
71  
72     /**
73      * DOCUMENT ME!
74      *
75      * @return DOCUMENT ME!
76      *
77      * @throws JspException DOCUMENT ME!
78      */
79     public int doAfterBody() throws JspException   {
80        DbFormTag myParent = getParentForm(); 
81  
82        try {
83           // each rendering loop represents one row of data.
84           // for every row we need to print some data needed by the controller servlet in order to
85           // correctly dispatching and eventually modifying our data.
86           //
87           // now the key of the current dataset is printed out (always)
88           // this key will be used by actions such as delete or update.
89           if (myParent.getTable() != null) {
90              String   curKeyString = myParent.getTable()
91                                            .getKeyPositionString(myParent
92                                                                  .getResultSetVector());
93  
94              if (!Util.isNull(curKeyString)) {
95                 curKeyString = Util.encode(curKeyString,
96                                            pageContext.getRequest().getCharacterEncoding());
97                 myParent.appendToChildElementOutput("<input type=\"hidden\" name=\"k_"
98                                                     + myParent.getTable().getId()
99                                                     + "_"
100                                                    + myParent.getPositionPath()
101                                                    + "\" value=\""
102                                                    + curKeyString + "\"/>");
103             }
104          }
105       } catch (UnsupportedEncodingException   uee) {
106          throw new JspException  (uee.toString());
107       }
108       // field values that have not been rendered by html tags but that is determinated by field
109       // mapping between main- and subform are rendered now:
110       if (myParent.isSubForm() && myParent.isFooterReached() && Util.getTrue(getAllowNew())) {
111          myParent.appendToChildElementOutput(myParent.produceLinkedTags()); // print hidden-fields for missing insert-fields we can determinated
112       }
113 
114 
115       return SKIP_BODY;
116    }
117 
118 
119    /**
120     * DOCUMENT ME!
121     *
122     * @param t DOCUMENT ME!
123     *
124     * @throws Throwable DOCUMENT ME!
125     */
126    public void doCatch(Throwable   t) throws Throwable   {
127       throw t;
128    }
129 
130 
131    /**
132     * DOCUMENT ME!
133     *
134     * @return DOCUMENT ME!
135     *
136     * @throws JspException DOCUMENT ME!
137     */
138    public int doEndTag() throws JspException   {
139       try {
140          if (bodyContent != null) {
141             bodyContent.writeOut(bodyContent.getEnclosingWriter());
142             bodyContent.clearBody();
143 
144             // workaround for duplicate rows in JRun 3.1
145          }
146       } catch (java.io.IOException   e) {
147          throw new JspException  ("IO Error: " + e.getMessage());
148       }
149 
150       return EVAL_PAGE;
151    }
152 
153 
154    // by default this is "true" - if so, the body is rendered at least 1 time, even if there are no data rows in the table. this enables the user to insert a new data row. - to disable this feature, allowNew has to be set to "false"
155 
156    /**
157     * DOCUMENT ME!
158     */
159    public void doFinally() {
160       allowNew = "true";
161    }
162 
163 
164    /**
165     * DOCUMENT ME!
166     *
167     * @return DOCUMENT ME!
168     */
169    public int doStartTag() throws javax.servlet.jsp.JspException   {
170       DbFormTag myParent = getParentForm();
171       ResultSetVector rsv = myParent.getResultSetVector();
172       // the body may be rendered under the following circumstances:
173       // - resultSetVector > 0 && not footer reached => render a row
174       // - resultSetVector == 0 && allowNew==true    => insert a new row
175       if (
176             (!ResultSetVector.isNull(rsv) && myParent.isFooterReached())  
177             ||
178             (ResultSetVector.isNull(rsv) && Util.getFalse(allowNew))
179           ) {
180             return SKIP_BODY;
181       }
182 
183       myParent.updatePositionPath();
184       // to enable access from jsp we provide a variable
185       // #fixme: we need a more convenient data access structure
186       //
187       // #fixme: this is a CRAZY WEIRED ODD SQUARE WORKAROUND
188       //
189 
190       if (!ResultSetVector.isNull(rsv)) {
191          Map   dbforms = (Map  ) pageContext.getAttribute("dbforms");
192 
193          if (dbforms != null) {
194             DbFormContext dbContext = (DbFormContext) dbforms.get(myParent
195                                                                   .getName());
196             if (dbContext != null) {
197                dbContext.setCurrentRow(rsv.getCurrentRowAsMap());
198                try {
199                   dbContext.setPosition(Util.encode(myParent.getTable().getPositionString(rsv),
200                                                     pageContext.getRequest().getCharacterEncoding()));
201                } catch (Exception   e) {
202                   throw new JspException  (e.getMessage());
203                }
204             }
205          }
206 
207          if (!rsv.isLast()) {
208             rsv.moveNext(); // teleport us to future...
209 
210             // This must be done because currentRow_xxx is reread from 
211             // the pagecontext after(!) the body of the tag. This means 
212             // that the current body contains the currentRow of rsv(i - 1)
213             // # jp 27-06-2001: replacing "." by "_", so that SCHEMATA can be used
214             pageContext.setAttribute("currentRow_"
215                                      + myParent.getTableName().replace('.', '_'),
216                                      rsv.getCurrentRowAsMap());
217 
218             try {
219                pageContext.setAttribute("position_"
220                                         + myParent.getTableName().replace('.',
221                                                                           '_'),
222                                         Util.encode(myParent.getTable().getPositionString(rsv),
223                                                     pageContext.getRequest().getCharacterEncoding()));
224             } catch (Exception   e) {
225                throw new JspException  (e.getMessage());
226             }
227 
228             rsv.movePrevious(); // ...and back to present ;=)
229          }
230       }
231 
232       return EVAL_BODY_BUFFERED;
233    }
234 }
235
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