DbLinkURLTag


1   /*
2    * $Header: /cvsroot/jdbforms/dbforms/src/org/dbforms/taglib/DbLinkURLTag.java,v 1.30 2004/08/18 12:26:07 hkollmann Exp $
3    * $Revision: 1.30 $
4    * $Date: 2004/08/18 12:26:07 $
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.apache.commons.logging.Log;
27  import org.apache.commons.logging.LogFactory;
28  
29  import org.dbforms.config.Field;
30  import org.dbforms.config.FieldValue;
31  import org.dbforms.config.FieldValues;
32  import org.dbforms.config.Table;
33  
34  import org.dbforms.util.Util;
35  
36  import java.io.UnsupportedEncodingException  ;
37  
38  import javax.servlet.http.HttpServletRequest  ;
39  import javax.servlet.http.HttpServletResponse  ;
40  import javax.servlet.jsp.JspException  ;
41  
42  
43  
44  /**
45   * <p>
46   * the 3 examples below produce all the same result
47   * </p>
48   *
49   * <p>
50   * &lt;linkURL HREF="customer.jsp" table="customer" position="1:2:12-3:4:1992"
51   * /&gt;
52   * </p>
53   *
54   * <p>
55   * &lt;linkURL HREF="customer.jsp" table="customer" position="&lt;%= currentKey
56   * %&gt;" /&gt;
57   * </p>
58   *
59   * <p>
60   * &lt;linkURL HREF="customer.jsp" table="customer" /&gt; &lt;position
61   * fieldName="id" value="103" /&gt; &lt;position fieldName="cust_lang"
62   * value="2" /&gt; &lt;/linkURL&gt;
63   * </p>
64   *
65   * <p>
66   * result (off course without the line feeds)
67   * </p>
68   * <pre>/servlet/control?
69   * ac_goto_x=t&
70   * data_ac_goto_x_fu=/customer.jsp&
71   * data_ac_goto_x_destTable=17&
72   * data_ac_goto_x_destPos=103~2</pre>
73   *
74   * <p>
75   * Use it like this:
76   * </p>
77   * <pre><a HREF="&lt;linkURL HREF="customer.jsp" tableName="customer" position="103~2" /&gt;"> some text </a></pre>
78   *
79   * @author Joachim Peer
80   */
81  public class DbLinkURLTag extends DbBaseHandlerTag
82     implements javax.servlet.jsp.tagext.TryCatchFinally   {
83     private static Log            logCat = LogFactory.getLog(DbLinkURLTag.class
84                                                              .getName()); // logging category for this class
85     private transient FieldValues positionFv; // fields and their values, provided by embedded DbLinkPositionItem-Elements
86  
87     /**
88      * used if parentTable is different to tableName: field(s) in this forme
89      * that is/are linked to the parent form
90      */
91     private String   childField;
92  
93     // -- properties
94     private String   href;
95     private String   keyToDestPos;
96     private String   keyToKeyToDestPos;
97  
98     /**
99      * used if parentTable is different to tableName: field(s) in the main form
100     * that is/are linked to this form
101     */
102    private String   parentField;
103    private String   position;
104    private String   singleRow = "false";
105    private String   tableName;
106 
107    /**
108     * Sets the childField.
109     *
110     * @param childField The childField to set
111     */
112    public void setChildField(String   childField) {
113       this.childField = childField;
114    }
115 
116 
117    /**
118     * Returns the childField.
119     *
120     * @return String
121     */
122    public String   getChildField() {
123       return childField;
124    }
125 
126 
127    /**
128     * DOCUMENT ME!
129     *
130     * @param position DOCUMENT ME!
131     */
132    public void setDestPos(String   position) {
133       this.position = position;
134    }
135 
136 
137    /**
138     * DOCUMENT ME!
139     *
140     * @return DOCUMENT ME!
141     */
142    public String   getDestPos() {
143       return position;
144    }
145 
146 
147    /**
148     * DOCUMENT ME!
149     *
150     * @param href DOCUMENT ME!
151     */
152    public void setHref(String   href) {
153       this.href = href;
154    }
155 
156 
157    /**
158     * DOCUMENT ME!
159     *
160     * @return DOCUMENT ME!
161     */
162    public String   getHref() {
163       return href;
164    }
165 
166 
167    /**
168     * Sets the keyToDestPos.
169     *
170     * @param keyToDestPos The keyToDestPos to set
171     */
172    public void setKeyToDestPos(String   keyToDestPos) {
173       this.keyToDestPos = keyToDestPos;
174    }
175 
176 
177    /**
178     * Returns the keyToDestPos.
179     *
180     * @return String
181     */
182    public String   getKeyToDestPos() {
183       return keyToDestPos;
184    }
185 
186 
187    /**
188     * Sets the keyToKeyToDestPos.
189     *
190     * @param keyToKeyToDestPos The keyToKeyToDestPos to set
191     */
192    public void setKeyToKeyToDestPos(String   keyToKeyToDestPos) {
193       this.keyToKeyToDestPos = keyToKeyToDestPos;
194    }
195 
196 
197    /**
198     * Returns the keyToKeyToDestPos.
199     *
200     * @return String
201     */
202    public String   getKeyToKeyToDestPos() {
203       return keyToKeyToDestPos;
204    }
205 
206 
207    /**
208     * Sets the parentField.
209     *
210     * @param parentField The parentField to set
211     */
212    public void setParentField(String   parentField) {
213       this.parentField = parentField;
214    }
215 
216 
217    /**
218     * Returns the parentField.
219     *
220     * @return String
221     */
222    public String   getParentField() {
223       return parentField;
224    }
225 
226 
227    /**
228     * DOCUMENT ME!
229     *
230     * @param position DOCUMENT ME!
231     */
232    public void setPosition(String   position) {
233       this.position = position;
234    }
235 
236 
237    /**
238     * DOCUMENT ME!
239     *
240     * @return DOCUMENT ME!
241     */
242    public String   getPosition() {
243       return position;
244    }
245 
246 
247    /**
248     * DOCUMENT ME!
249     *
250     * @param string
251     */
252    public void setSingleRow(String   string) {
253       singleRow = string;
254    }
255 
256 
257    /**
258     * DOCUMENT ME!
259     *
260     * @return the attribute
261     */
262    public String   getSingleRow() {
263       return singleRow;
264    }
265 
266 
267    /**
268     * DOCUMENT ME!
269     *
270     * @return DOCUMENT ME!
271     */
272    public Table getTable() {
273       if (!Util.isNull(tableName)) {
274          return getConfig()
275                    .getTableByName(tableName);
276       } else if (getParentForm() != null) { // we must try if we get info from parentForm
277 
278          return getParentForm()
279                    .getTable();
280       } else {
281          throw new IllegalArgumentException  ("no table specified. either you define expliclty the attribute \"tableName\" or you put this tag inside a db:form!");
282       }
283    }
284 
285 
286    /**
287     * DOCUMENT ME!
288     *
289     * @param tableName DOCUMENT ME!
290     */
291    public void setTableName(String   tableName) {
292       this.tableName = tableName;
293    }
294 
295 
296    /**
297     * to be called by DbLinkPositonItems
298     *
299     * @param field DOCUMENT ME!
300     * @param value DOCUMENT ME!
301     */
302    public void addPositionPart(Field  field,
303                                String   value) {
304       if (positionFv == null) {
305          positionFv = new FieldValues();
306       }
307 
308       // 2003-03-29 HKK: Change from Hashtable to FieldValueTable
309       FieldValue fv = new FieldValue(field, value);
310       positionFv.put(fv);
311    }
312 
313 
314    /**
315     * DOCUMENT ME!
316     *
317     * @return DOCUMENT ME!
318     *
319     * @throws JspException thrown when error occurs in processing the body of
320     *         this method
321     */
322    public int doBodyEndTag() throws javax.servlet.jsp.JspException   {
323       return SKIP_BODY;
324    }
325 
326 
327    /**
328     * @see javax.servlet.jsp.tagext.TryCatchFinally#doCatch(java.lang.Throwable)
329     */
330    public void doCatch(Throwable   t) throws Throwable   {
331       throw t;
332    }
333 
334 
335    /**
336     * DOCUMENT ME!
337     *
338     * @return DOCUMENT ME!
339     *
340     * @throws JspException thrown when error occurs in processing the body of
341     *         this method
342     */
343    public int doEndTag() throws javax.servlet.jsp.JspException   {
344       try {
345          HttpServletResponse   response = (HttpServletResponse  ) pageContext
346                                         .getResponse();
347 
348          String                s = makeUrl();
349          s = response.encodeURL(s);
350          pageContext.getOut()
351                     .write(s);
352       } catch (java.io.IOException   ioe) {
353          throw new JspException  ("IO Error: " + ioe.getMessage());
354       } catch (Exception   e) {
355          throw new JspException  ("Error: " + e.getMessage());
356       }
357 
358       return EVAL_PAGE;
359    }
360 
361 
362    /**
363     * DOCUMENT ME!
364     */
365    public void doFinally() {
366       logCat.info("doFinally called");
367       position = null;
368 
369       if (positionFv != null) {
370          positionFv.clear();
371       }
372 
373       positionFv        = null;
374       href              = null;
375       tableName         = null;
376       position          = null;
377       keyToDestPos      = null;
378       keyToKeyToDestPos = null;
379       singleRow         = "false";
380 
381       super.doFinally();
382    }
383 
384 
385    /**
386     * DOCUMENT ME!
387     *
388     * @return DOCUMENT ME!
389     *
390     * @throws JspException thrown when error occurs in processing the body of
391     *         this method
392     * @throws IllegalArgumentException thrown when some parameters are missing.
393     */
394    public int doStartTag() throws javax.servlet.jsp.JspException   {
395       if (Util.isNull(getPosition())) { // if position was not set explicitly,
396 
397          return EVAL_BODY_BUFFERED; // we have to evaluate body and hopefully find DbLinkPositionItems there
398       } else {
399          return SKIP_BODY; // if position was provided we don't need to look into body
400       }
401    }
402 
403 
404    /**
405     * DOCUMENT ME!
406     *
407     * @return DOCUMENT ME!
408     *
409     * @throws UnsupportedEncodingException DOCUMENT ME!
410     */
411    protected String   makeUrl() throws UnsupportedEncodingException   {
412       // determinate position inside table (key)
413       if (this.position == null) { // not explic. def. by attribute
414 
415          if (positionFv != null) { // but (maybe) defined by sub-elements (DbLinkPositionItem)
416             position = getTable()
417                           .getKeyPositionString(positionFv);
418          }
419       }
420 
421       // build tag
422       StringBuffer         tagBuf      = new StringBuffer  (200);
423       HttpServletRequest   request     = (HttpServletRequest  ) pageContext
424                                        .getRequest();
425       String               contextPath = request.getContextPath();
426       tagBuf.append(contextPath);
427 
428       // 2002-01-17 Fix contributed by Dirk Kraemer and Bertram Gong//
429       if (!contextPath.endsWith("/")) {
430          tagBuf.append("/");
431       }
432 
433       tagBuf.append("servlet/control?");
434 
435       String   tagName = "ac_goto";
436       tagBuf.append(getDataTag(tagName, "x", "t"));
437 
438       tagName = "data" + tagName + "_x";
439       tagBuf.append(getDataTag(tagName, "fu", href));
440 
441       // table is required. we force to define a valid table.
442       // because we do not want the developer to use this tag instead of
443       // normal <a HREF="">-tags to arbitrary (static) ressources, as this would slow down the application.
444       tagBuf.append(getDataTag(tagName, "destTable", getTable().getName()));
445 
446       // position within table is not required.
447       // if no position was provided/determinated, dbForm will navigate to the first row
448       // 2002-11-20 HKK: Fixed encoding bug!
449       tagBuf.append(getDataTag(tagName, "destPos",
450                                Util.encode(position,
451                                            pageContext.getRequest().getCharacterEncoding())));
452 
453       // 2002-11-21 HKK: Allow same keys as in dbgotobutton
454       tagBuf.append(getDataTag(tagName, "keyToDestPos",
455                                Util.encode(keyToDestPos,
456                                            pageContext.getRequest().getCharacterEncoding())));
457       tagBuf.append(getDataTag(tagName, "keyToKeyDestPos",
458                                Util.encode(keyToKeyToDestPos,
459                                            pageContext.getRequest().getCharacterEncoding())));
460 
461       // 2002-11-21 HKK: New: send parent table name as parameter if it is different to table
462       if (getTable() != getParentForm()
463                                  .getTable()) {
464          tagBuf.append(getDataTag(tagName, "srcTable",
465                                   getParentForm().getTable().getName()));
466          tagBuf.append(getDataTag(tagName, "childField",
467                                   Util.encode(childField,
468                                               pageContext.getRequest().getCharacterEncoding())));
469          tagBuf.append(getDataTag(tagName, "parentField",
470                                   Util.encode(parentField,
471                                               pageContext.getRequest().getCharacterEncoding())));
472       }
473 
474       tagBuf.append(getDataTag(tagName, "singleRow", getSingleRow()));
475 
476       String   s = tagBuf.toString();
477       s = s.substring(0, s.length() - 1);
478 
479       return s;
480    }
481 
482 
483    private String   getDataTag(String   primaryTagName,
484                              String   dataKey,
485                              String   dataValue) {
486       String   s = "";
487 
488       if (!Util.isNull(dataValue)) {
489          StringBuffer   tagBuf = new StringBuffer  ();
490          tagBuf.append(primaryTagName);
491          tagBuf.append("_");
492          tagBuf.append(dataKey);
493          tagBuf.append("=");
494          tagBuf.append(dataValue);
495          tagBuf.append("&");
496          s = tagBuf.toString();
497       }
498 
499       return s;
500    }
501 }
502
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