EventEngine


1   /*
2    * $Header: /cvsroot/jdbforms/dbforms/src/org/dbforms/event/EventEngine.java,v 1.37 2004/10/17 07:02:25 hkollmann Exp $
3    * $Revision: 1.37 $
4    * $Date: 2004/10/17 07:02:25 $
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.event;
25  
26  import org.apache.commons.logging.Log;
27  import org.apache.commons.logging.LogFactory;
28  
29  import org.dbforms.config.Constants;
30  import org.dbforms.config.DbFormsConfig;
31  import org.dbforms.config.Table;
32  
33  import org.dbforms.event.eventtype.EventType;
34  import org.dbforms.event.eventtype.EventTypeUtil;
35  
36  import org.dbforms.util.ParseUtil;
37  import org.dbforms.util.StringUtil;
38  import org.dbforms.util.Util;
39  
40  import java.util.Enumeration  ;
41  import java.util.Vector  ;
42  
43  import javax.servlet.http.HttpServletRequest  ;
44  
45  
46  
47  /**
48   * This class is invoked by the Controller-Servlet. It parses a request to find
49   * out which Event(s) need to be instanciated. The fine-grained parsing
50   * (parsing of additional data, etc) is done by the WebEvent-Object itself (in
51   * order to hide complexity from this class and to keep the framework open for
52   * implementations of new Event-classes)
53   *
54   * @author Joe Peer
55   *
56   */
57  public class EventEngine {
58     /** logging category for this class */
59     private static Log logCat = LogFactory.getLog(EventEngine.class.getName());
60  
61     /** instance of DatabaseEventFactory */
62     private DatabaseEventFactory dbEventFactory = DatabaseEventFactoryImpl
63                                                   .instance();
64     private DbFormsConfig        config;
65     private HttpServletRequest     request;
66  
67     /** instance of NavigationEventFactory */
68     private NavEventFactory navEventFactory = NavEventFactoryImpl.instance();
69  
70     /**
71      * this vector will contain which tables where on the jsp page: one jsp file
72      * may contain multiple dbforms, and each forms could contain many subforms
73      * nested inside
74      */
75     private Vector   involvedTables;
76  
77     /**
78      * Constructor.
79      *
80      * @param request the request object
81      * @param config the configuration object
82      */
83     public EventEngine(HttpServletRequest   request,
84                        DbFormsConfig      config) {
85        this.request = request;
86        this.config  = config;
87  
88        // find out which tables where on the jsp
89        involvedTables = parseInvolvedTables();
90     }
91  
92     /**
93      * Get the involvedTables attribute of the EventEngine class.
94      *
95      * @return the involvedTables attribute of the EventEngine class
96      */
97     public Vector   getInvolvedTables() {
98        return involvedTables;
99     }
100 
101 
102    /**
103     * Generate the primary event object, depending on the data contained into
104     * the incoming http request object.
105     *
106     * @return a new WebEvent object
107     */
108    public WebEvent generatePrimaryEvent() {
109       WebEvent e      = null;
110       String     action = ParseUtil.getFirstParameterStartingWith(request, "ac_");
111       String     customEvent = ParseUtil.getParameter(request, "customEvent");
112 
113       if (Util.isNull(action) && !Util.isNull(customEvent)) {
114          // 2003-07-21-HKK: fixing NS 4.79 bug! (From bug list)
115          action = customEvent.trim();
116       }
117 
118       // NOOP EVENT
119       //
120       // family: web event
121       if (Util.isNull(action)) {
122          logCat.info("##### N O O P   ELEMENT ######");
123          e = new NoopEvent(-1, request, config);
124          initializeWebEvent(e);
125 
126          return e;
127       }
128 
129       // RELOAD EVENT
130       //
131       // family: web event
132       //
133       // ReloadEvent use to refresh field values from request object
134       // and to allow server side manipulation for these fields
135       //
136       // This event is created if customEvent is set to re_x_x!!
137       //
138       if (action.startsWith("re_")) {
139          logCat.info("##### RELOAD  EVENT ######");
140          e = new PageReloadEvent(StringUtil.getEmbeddedStringAsInteger(action,
141                                                                       2, '_'),
142                                  request, config);
143          e.setType(EventType.EVENT_NAVIGATION_RELOAD);
144          initializeWebEvent(e);
145 
146          return e;
147       }
148 
149       // make the image button data (if any) look like a submit button;
150       action = getImageButtonAction(action);
151 
152       // get the EventType class and identify the event type
153       // and use the related factory class to create the event;
154       EventType eventType = EventTypeUtil.getEventType(action);
155 
156       switch (eventType.getEventGroup()) {
157          case EventType.EVENT_GROUP_DATABASE: {
158             logCat.info("::generatePrimaryEvent - generating a database event");
159             e = dbEventFactory.createEvent(action, request, config);
160 
161             break;
162          }
163 
164          case EventType.EVENT_GROUP_NAVIGATION: {
165             logCat.info("::generatePrimaryEvent - generating a navigation event");
166             e = navEventFactory.createEvent(action, request, config);
167 
168             break;
169          }
170 
171          default: {
172             logCat.error("::generatePrimaryEvent - WARNING: generating NO event. Why ?");
173 
174             break;
175          }
176       }
177 
178       // setting the followUp attributes for the generated event
179       setEventFollowUp(e, action);
180 
181       return e;
182    }
183 
184 
185    /**
186     * Generate secundary events (update events)
187     *
188     * @param actTable DOCUMENT ME!
189     * @param exclude the parent web event (related to the main form)
190     *
191     * @return DOCUMENT ME!
192     */
193    public Enumeration   generateSecundaryEvents(Table    actTable,
194                                               WebEvent exclude) {
195       Vector    result           = new Vector  ();
196       int     excludeTableId   = -1;
197       String    excludeKeyId     = null;
198       boolean collissionDanger = false;
199 
200       // first of all, we check if there is some real potential for collisions
201       // in the "to exclude"-event
202       if (exclude instanceof DatabaseEvent) {
203          collissionDanger = true;
204          excludeTableId   = exclude.getTable()
205                                    .getId();
206          excludeKeyId = ((DatabaseEvent) exclude).getKeyId();
207       }
208 
209       String   param = "autoupdate_" + String.valueOf(actTable.getId());
210       String   res = ParseUtil.getParameter(request, param);
211 
212       // auto-updating may be disabled, so we have to check:
213       if (res.equalsIgnoreCase("true")
214                 || (res.equalsIgnoreCase("OnUpdateOnly")
215                 && exclude.getType()
216                                 .equals("update"))) {
217          // we can only update existing rowsets. so we just look for
218          // key-values
219          String        paramStub          = "k_" + actTable.getId() + "_";
220          Enumeration   keysOfCurrentTable = ParseUtil.getParametersStartingWith(request,
221                                                                               paramStub)
222                                                    .elements();
223 
224          while (keysOfCurrentTable.hasMoreElements()) {
225             String   aKeyParam = (String  ) keysOfCurrentTable.nextElement();
226             String   keyId = aKeyParam.substring(paramStub.length());
227 
228             logCat.info("autoaupdate debug info: keyId=" + keyId
229                         + " excludeKeyId=" + excludeKeyId);
230 
231             if (!collissionDanger
232                       || (excludeTableId != actTable.getId())
233                       || !keyId.equals(excludeKeyId)) {
234                DatabaseEvent e = dbEventFactory.createUpdateEvent(actTable
235                                                                   .getId(),
236                                                                   keyId,
237                                                                   request,
238                                                                   config);
239                result.addElement(e);
240             }
241          }
242 
243          // now try the same with insert records
244          // but only if
245          if (collissionDanger && (excludeTableId != actTable.getId())) {
246             paramStub = "f_" + actTable.getId() + "_"
247                         + Constants.FIELDNAME_INSERTPREFIX;
248 
249             Vector   v = ParseUtil.getParametersStartingWith(request, paramStub);
250 
251             if (v.size() > 0) {
252                String   aKeyParam = (String  ) v.firstElement();
253                String   keyId = aKeyParam.substring(paramStub.length());
254                keyId = StringUtil.getEmbeddedString(keyId, 0, '_');
255 
256                DatabaseEvent e = dbEventFactory.createInsertEvent(actTable
257                                                                   .getId(),
258                                                                   keyId,
259                                                                   request,
260                                                                   config);
261                result.addElement(e);
262             }
263          }
264       }
265 
266       return result.elements();
267    }
268 
269 
270    /**
271     * Sets the eventFollowUp and followUpOnError attributes of the input Event
272     * object
273     *
274     * @param e the event object
275     * @param action the action string
276     */
277    private void setEventFollowUp(WebEvent e,
278                                  String     action) {
279       // now we have to find the followup-site the app-developer wants us to
280       // display.
281       String   followUp = ParseUtil.getParameter(request, "data" + action + "_fu");
282 
283       // if not...
284       // ...then check if �2-followup exists (should always exist!)
285       if (followUp == null) {
286          followUp = ParseUtil.getParameter(request,
287                                            "fu_"
288                                            + (((e == null)
289                                               || (e.getTable() == null)) ? (-1)
290                                                                          : e.getTable().getId()));
291       }
292 
293       logCat.info("setting follow up to:" + followUp);
294 
295       if (e != null) {
296          e.setFollowUp(followUp);
297       }
298 
299       String   followUpOnError = ParseUtil.getParameter(request,
300                                                       "data" + action + "_fue");
301 
302       // if not...
303       // ...then check if �2-followup exists
304       if (followUpOnError == null) {
305          followUpOnError = ParseUtil.getParameter(request,
306                                                   "fue_"
307                                                   + (((e == null)
308                                                      || (e.getTable() == null))
309                                                      ? (-1)
310                                                      : e.getTable().getId()));
311       }
312 
313       // Still no followup on error - use general followup
314       if (followUpOnError == null) {
315          followUpOnError = followUp;
316       }
317 
318       logCat.info("setting follow up on Error to:" + followUpOnError);
319 
320       if (e != null) {
321          e.setFollowUpOnError(followUpOnError);
322       }
323    }
324 
325 
326    /**
327     * Make the image button data look like a submit button. <br>
328     * Image buttons submit different parameters than submit buttons for submit
329     * the browser sends one value parameter:ac_insert_0_root=Submit this bug!
330     * for image buttons, the browser returns two values, showing the x and y
331     * position of the mouse parameter ac_insert_0_root.y=24 parameter
332     * ac_insert_0_root.x=34
333     *
334     * @param action Description of the Parameter
335     *
336     * @return The imageButtonAction value
337     */
338    private String   getImageButtonAction(String   action) {
339       if (action.endsWith(".y") || action.endsWith(".x")) {
340          action = action.substring(0, action.length() - 2);
341       }
342 
343       logCat.info("::getImageButtonAction - action = [" + action + "]");
344 
345       return action;
346    }
347 
348 
349    /**
350     * PRIVATE METHODS here
351     *
352     * @param contextPath DOCUMENT ME!
353     * @param sourcePath DOCUMENT ME!
354     *
355     * @return DOCUMENT ME!
356     */
357    /**
358     * Sets the sourcePath attribute of the EventEngine object
359     *
360     * @param contextPath The new sourcePath value
361     * @param sourcePath The new sourcePath value
362     *
363     * @return Description of the Return Value
364     */
365    private String   setSourcePath(String   contextPath,
366                                 String   sourcePath) {
367       if (!Util.isNull(contextPath)
368                 && !Util.isNull(sourcePath)
369                 && sourcePath.startsWith(contextPath)) {
370          // shouldn't! just make sure!
371          if (contextPath.endsWith("/")) {
372             sourcePath = sourcePath.substring(contextPath.length() - 1);
373          } else {
374             sourcePath = sourcePath.substring(contextPath.length());
375          }
376       }
377 
378       return sourcePath;
379    }
380 
381 
382    /**
383     * Initialize the input web event.
384     *
385     * @param e the web event to initialize
386     */
387    private void initializeWebEvent(WebEvent e) {
388       String   contextPath = request.getContextPath();
389       String   sourcePath = ParseUtil.getParameter(request, "source");
390 
391       logCat.info("sourcePath = " + sourcePath);
392       sourcePath = setSourcePath(contextPath, sourcePath);
393 
394       e.setFollowUp(sourcePath);
395       logCat.info("followup=" + e.getFollowUp());
396    }
397 
398 
399    /**
400     * Find out which tables where on the jsp (one jsp file may contain multiple
401     * dbforms, and each forms could contain many subforms nested inside!)
402     *
403     * @return the vector object containing the Table objects involved with the
404     *         main table
405     */
406    private Vector   parseInvolvedTables() {
407       String  [] invTables = ParseUtil.getParameterValues(request, "invtable");
408 
409       // in empty forms, for example, we don't have any involved tables..!
410       if (invTables == null) {
411          return null;
412       }
413 
414       Vector   result = new Vector  ();
415 
416       for (int i = 0; i < invTables.length; i++) {
417          int   tableIndex = Integer.parseInt(invTables[i]);
418          Table t = config.getTable(tableIndex);
419 
420          result.addElement(t);
421       }
422 
423       return result;
424    }
425 }
426
A to Z: JavaDoc & Examples Daily Java News & Articles Open Source Projects Open Source Codes Free Computer Books Remove Frame
Popular Tags