1 package org.apache.turbine.modules;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.lang.reflect.InvocationTargetException;
23 import java.lang.reflect.Method;
24 import java.util.Arrays;
25
26 import org.apache.commons.collections.map.MultiKeyMap;
27 import org.apache.commons.lang.StringUtils;
28 import org.apache.commons.logging.Log;
29 import org.apache.commons.logging.LogFactory;
30 import org.apache.fulcrum.parser.ParameterParser;
31 import org.apache.fulcrum.parser.ValueParser.URLCaseFolding;
32 import org.apache.turbine.Turbine;
33 import org.apache.turbine.TurbineConstants;
34 import org.apache.turbine.annotation.TurbineActionEvent;
35 import org.apache.turbine.pipeline.PipelineData;
36
37 /**
38 * <p>
39 *
40 * This is an alternative to the Action class that allows you to do
41 * event based actions. Essentially, you label all your submit buttons
42 * with the prefix of "eventSubmit_" and the suffix of "methodName".
43 * For example, "eventSubmit_doDelete". Then any class that subclasses
44 * this class will get its "doDelete(PipelineData data)" method executed.
45 * If for any reason, it was not able to execute the method, it will
46 * fall back to executing the doPerform() method which is required to
47 * be implemented.
48 *
49 * <p>
50 *
51 * Limitations:
52 *
53 * <p>
54 *
55 * Because ParameterParser makes all the key values lowercase, we have
56 * to do some work to format the string into a method name. For
57 * example, a button name eventSubmit_doDelete gets converted into
58 * eventsubmit_dodelete. Thus, we need to form some sort of naming
59 * convention so that dodelete can be turned into doDelete.
60 *
61 * <p>
62 *
63 * Thus, the convention is this:
64 *
65 * <ul>
66 * <li>The variable name MUST have the prefix "eventSubmit_".</li>
67 * <li>The variable name after the prefix MUST begin with the letters
68 * "do".</li>
69 * <li>The first letter after the "do" will be capitalized and the
70 * rest will be lowercase</li>
71 * </ul>
72 *
73 * If you follow these conventions, then you should be ok with your
74 * method naming in your Action class.
75 *
76 * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens </a>
77 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
78 * @author <a href="quintonm@bellsouth.net">Quinton McCombs</a>
79 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
80 * @version $Id: ActionEvent.java 1706425 2015-10-02 14:47:51Z tv $
81 */
82 public abstract class ActionEvent extends Action
83 {
84 /** Logging */
85 protected Log log = LogFactory.getLog(this.getClass());
86
87 /** The name of the button to look for. */
88 protected static final String BUTTON = "eventSubmit_";
89 /** The length of the button to look for. */
90 protected static final int BUTTON_LENGTH = BUTTON.length();
91 /** The default method. */
92 protected static final String DEFAULT_METHOD = "doPerform";
93 /** The prefix of the method name. */
94 protected static final String METHOD_NAME_PREFIX = "do";
95 /** The length of the method name. */
96 protected static final int METHOD_NAME_LENGTH = METHOD_NAME_PREFIX.length();
97 /** The length of the button to look for. */
98 protected static final int LENGTH = BUTTON.length();
99
100 /**
101 * If true, the eventSubmit_do<xxx> variable must contain
102 * a not null value to be executed.
103 */
104 private boolean submitValueKey = false;
105
106 /**
107 * If true, then exceptions raised in eventSubmit_do<xxx> methods
108 * as well as in doPerform methods are bubbled up to the Turbine
109 * servlet's handleException method.
110 */
111 protected boolean bubbleUpException = true;
112
113 /**
114 * Cache for the methods to invoke
115 */
116 private MultiKeyMap/* <String, Method> */ methodCache = new MultiKeyMap/* <String, Method> */();
117
118 /**
119 * C'tor
120 */
121 public ActionEvent()
122 {
123 super();
124
125 submitValueKey = Turbine.getConfiguration()
126 .getBoolean(TurbineConstants.ACTION_EVENTSUBMIT_NEEDSVALUE_KEY,
127 TurbineConstants.ACTION_EVENTSUBMIT_NEEDSVALUE_DEFAULT);
128 bubbleUpException = Turbine.getConfiguration()
129 .getBoolean(TurbineConstants.ACTION_EVENT_BUBBLE_EXCEPTION_UP,
130 TurbineConstants.ACTION_EVENT_BUBBLE_EXCEPTION_UP_DEFAULT);
131
132 if (log.isDebugEnabled())
133 {
134 log.debug(submitValueKey
135 ? "ActionEvent accepts only eventSubmit_do Keys with a value != 0"
136 : "ActionEvent accepts all eventSubmit_do Keys");
137 log.debug(bubbleUpException
138 ? "ActionEvent will bubble exceptions up to Turbine.handleException() method"
139 : "ActionEvent will not bubble exceptions up.");
140 }
141 }
142
143 /**
144 * Retrieve a method of the given name and signature. The value is cached.
145 *
146 * @param name the name of the method
147 * @param signature an array of classes forming the signature of the method
148 * @param pp ParameterParser for correct folding
149 *
150 * @return the method object
151 * @throws NoSuchMethodException if the method does not exist
152 */
153 protected Method getMethod(String name, Class<?>[] signature, ParameterParser pp) throws NoSuchMethodException
154 {
155 Method method = (Method) this.methodCache.get(name, signature);
156
157 if (method == null)
158 {
159 // Try annotations of public methods
160 Method[] methods = getClass().getMethods();
161 for (Method m : methods)
162 {
163 if (m.isAnnotationPresent(TurbineActionEvent.class))
164 {
165 TurbineActionEvent tae = m.getAnnotation(TurbineActionEvent.class);
166 if (name.equals(pp.convert(tae.value()))
167 && Arrays.equals(signature, m.getParameterTypes()))
168 {
169 method = m;
170 break;
171 }
172 }
173 }
174
175 // Try legacy mode
176 if (method == null)
177 {
178 String tmp = name.toLowerCase().substring(METHOD_NAME_LENGTH);
179 method = getClass().getMethod(METHOD_NAME_PREFIX + StringUtils.capitalize(tmp), signature);
180 }
181
182 this.methodCache.put(name, signature, method);
183 }
184
185 return method;
186 }
187
188 /**
189 * This overrides the default Action.doPerform() to execute the
190 * doEvent() method. If that fails, then it will execute the
191 * doPerform() method instead.
192 *
193 * @param pipelineData Turbine information.
194 * @exception Exception a generic exception.
195 */
196 @Override
197 public void doPerform(PipelineData pipelineData)
198 throws Exception
199 {
200 ParameterParser pp = pipelineData.get(Turbine.class, ParameterParser.class);
201 executeEvents(pp, new Class<?>[]{ PipelineData.class }, new Object[]{ pipelineData });
202 }
203
204 /**
205 * This method should be called to execute the event based system.
206 *
207 * @param pp the parameter parser
208 * @param signature the signature of the method to call
209 * @param parameters the parameters for the method to call
210 *
211 * @exception Exception a generic exception.
212 */
213 protected void executeEvents(ParameterParser pp, Class<?>[] signature, Object[] parameters)
214 throws Exception
215 {
216 // Name of the button.
217 String theButton = null;
218
219 String button = pp.convert(BUTTON);
220 String key = null;
221
222 // Loop through and find the button.
223 for (String k : pp)
224 {
225 key = k;
226 if (key.startsWith(button))
227 {
228 if (considerKey(key, pp))
229 {
230 theButton = key;
231 break;
232 }
233 }
234 }
235
236 if (theButton == null)
237 {
238 theButton = BUTTON + DEFAULT_METHOD;
239 key = null;
240 }
241
242 theButton = formatString(theButton, pp);
243 Method method = null;
244
245 try
246 {
247 method = getMethod(theButton, signature, pp);
248 }
249 catch (NoSuchMethodException e)
250 {
251 method = getMethod(DEFAULT_METHOD, signature, pp);
252 }
253 finally
254 {
255 if (key != null)
256 {
257 pp.remove(key);
258 }
259 }
260
261 try
262 {
263 if (log.isDebugEnabled())
264 {
265 log.debug("Invoking " + method);
266 }
267
268 method.invoke(this, parameters);
269 }
270 catch (InvocationTargetException ite)
271 {
272 Throwable t = ite.getTargetException();
273 if (bubbleUpException)
274 {
275 if (t instanceof Exception)
276 {
277 throw (Exception) t;
278 }
279 else
280 {
281 throw ite;
282 }
283 }
284 else
285 {
286 log.error("Invokation of " + method , t);
287 }
288 }
289 }
290
291 /**
292 * This method does the conversion of the lowercase method name
293 * into the proper case.
294 *
295 * @param input The unconverted method name.
296 * @param pp The parameter parser (for correct folding)
297 * @return A string with the method name in the proper case.
298 */
299 protected String formatString(String input, ParameterParser pp)
300 {
301 String tmp = input;
302
303 if (StringUtils.isNotEmpty(input))
304 {
305 tmp = input.toLowerCase();
306
307 // Chop off suffixes (for image type)
308 String methodName = (tmp.endsWith(".x") || tmp.endsWith(".y"))
309 ? input.substring(0, input.length() - 2)
310 : input;
311
312 if (pp.getUrlFolding() == URLCaseFolding.NONE)
313 {
314 tmp = methodName.substring(BUTTON_LENGTH);
315 }
316 else
317 {
318 tmp = methodName.toLowerCase().substring(BUTTON_LENGTH);
319 }
320 }
321
322 return tmp;
323 }
324
325 /**
326 * Checks whether the selected key really is a valid event.
327 *
328 * @param key The selected key
329 * @param pp The parameter parser to look for the key value
330 *
331 * @return true if this key is really an ActionEvent Key
332 */
333 protected boolean considerKey(String key, ParameterParser pp)
334 {
335 if (!submitValueKey)
336 {
337 log.debug("No Value required, accepting " + key);
338 return true;
339 }
340 else
341 {
342 // If the action.eventsubmit.needsvalue key is true,
343 // events with a "0" or empty value are ignored.
344 // This can be used if you have multiple eventSubmit_do<xxx>
345 // fields in your form which are selected by client side code,
346 // e.g. JavaScript.
347 //
348 // If this key is unset or missing, nothing changes for the
349 // current behavior.
350 //
351 String keyValue = pp.getString(key);
352 log.debug("Key Value is " + keyValue);
353 if (StringUtils.isEmpty(keyValue))
354 {
355 log.debug("Key is empty, rejecting " + key);
356 return false;
357 }
358
359 try
360 {
361 if (Integer.parseInt(keyValue) != 0)
362 {
363 log.debug("Integer != 0, accepting " + key);
364 return true;
365 }
366 }
367 catch (NumberFormatException nfe)
368 {
369 // Not a number. So it might be a
370 // normal Key like "continue" or "exit". Accept
371 // it.
372 log.debug("Not a number, accepting " + key);
373 return true;
374 }
375 }
376 log.debug("Rejecting " + key);
377 return false;
378 }
379 }