001package org.apache.turbine.modules;
002
003/*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 *
012 *   http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied.  See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022import java.lang.annotation.Annotation;
023
024
025import java.lang.reflect.InvocationTargetException;
026import java.lang.reflect.Method;
027import java.util.Arrays;
028
029import org.apache.commons.collections.map.MultiKeyMap;
030import org.apache.commons.lang.StringUtils;
031import org.apache.commons.logging.Log;
032import org.apache.commons.logging.LogFactory;
033import org.apache.fulcrum.parser.ParameterParser;
034import org.apache.fulcrum.parser.ValueParser.URLCaseFolding;
035import org.apache.turbine.Turbine;
036import org.apache.turbine.TurbineConstants;
037import org.apache.turbine.annotation.AnnotationProcessor;
038import org.apache.turbine.annotation.TurbineActionEvent;
039import org.apache.turbine.annotation.TurbineConfiguration;
040import org.apache.turbine.pipeline.PipelineData;
041
042/**
043 * <p>
044 *
045 * This is an alternative to the Action class that allows you to do
046 * event based actions. Essentially, you label all your submit buttons
047 * with the prefix of "eventSubmit_" and the suffix of "methodName".
048 * For example, "eventSubmit_doDelete". Then any class that subclasses
049 * this class will get its "doDelete(PipelineData data)" method executed.
050 * If for any reason, it was not able to execute the method, it will
051 * fall back to executing the doPerform() method which is required to
052 * be implemented.
053 *
054 * <p>
055 *
056 * Limitations:
057 *
058 * <p>
059 *
060 * Because ParameterParser makes all the key values lowercase, we have
061 * to do some work to format the string into a method name. For
062 * example, a button name eventSubmit_doDelete gets converted into
063 * eventsubmit_dodelete. Thus, we need to form some sort of naming
064 * convention so that dodelete can be turned into doDelete.
065 *
066 * <p>
067 *
068 * Thus, the convention is this:
069 *
070 * <ul>
071 * <li>The variable name MUST have the prefix "eventSubmit_".</li>
072 * <li>The variable name after the prefix MUST begin with the letters
073 * "do".</li>
074 * <li>The first letter after the "do" will be capitalized and the
075 * rest will be lowercase</li>
076 * </ul>
077 *
078 * If you follow these conventions, then you should be ok with your
079 * method naming in your Action class.
080 *
081 * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens </a>
082 * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
083 * @author <a href="quintonm@bellsouth.net">Quinton McCombs</a>
084 * @author <a href="mailto:peter@courcoux.biz">Peter Courcoux</a>
085 * @version $Id: ActionEvent.java 1812628 2017-10-19 12:34:25Z gk $
086 */
087public abstract class ActionEvent extends Action
088{
089        /** Logging */
090        protected Log log = LogFactory.getLog(this.getClass());
091
092        /** The name of the button to look for. */
093        protected static final String BUTTON = "eventSubmit_";
094        /** The length of the button to look for. */
095        protected static final int BUTTON_LENGTH = BUTTON.length();
096    /** The default method. */
097    protected static final String DEFAULT_METHOD = "doPerform";
098        /** The prefix of the method name. */
099        protected static final String METHOD_NAME_PREFIX = "do";
100        /** The length of the method name. */
101        protected static final int METHOD_NAME_LENGTH = METHOD_NAME_PREFIX.length();
102        /** The length of the button to look for. */
103        protected static final int LENGTH = BUTTON.length();
104
105        /**
106         * If true, the eventSubmit_do&lt;xxx&gt; variable must contain
107         * a not null value to be executed.
108         */
109    @TurbineConfiguration( TurbineConstants.ACTION_EVENTSUBMIT_NEEDSVALUE_KEY )
110        private boolean submitValueKey = TurbineConstants.ACTION_EVENTSUBMIT_NEEDSVALUE_DEFAULT;
111
112        /**
113         * If true, then exceptions raised in eventSubmit_do&lt;xxx&gt; methods
114         * as well as in doPerform methods are bubbled up to the Turbine
115         * servlet's handleException method.
116         */
117    @TurbineConfiguration( TurbineConstants.ACTION_EVENT_BUBBLE_EXCEPTION_UP )
118        protected boolean bubbleUpException = TurbineConstants.ACTION_EVENT_BUBBLE_EXCEPTION_UP_DEFAULT;
119
120        /**
121         * Cache for the methods to invoke
122         */
123        private MultiKeyMap/* <String, Method> */ methodCache = new MultiKeyMap/* <String, Method> */();
124
125        /**
126         * Retrieve a method of the given name and signature. The value is cached.
127         *
128         * @param name the name of the method
129         * @param signature an array of classes forming the signature of the method
130         * @param pp ParameterParser for correct folding
131         *
132         * @return the method object
133         * @throws NoSuchMethodException if the method does not exist
134         */
135        protected Method getMethod(String name, Class<?>[] signature, ParameterParser pp) throws NoSuchMethodException
136        {
137            Method method = (Method) this.methodCache.get(name, signature);
138
139            if (method == null)
140            {
141                // Try annotations of public methods
142                Method[] methods = getClass().getMethods();
143
144        methodLoop:
145                for (Method m : methods)
146                {
147                    Annotation[] annotations = AnnotationProcessor.getAnnotations(m);
148                    for (Annotation a : annotations)
149                    {
150                    if (a instanceof TurbineActionEvent)
151                    {
152                        TurbineActionEvent tae = (TurbineActionEvent) a;
153                        if (name.equals(pp.convert(tae.value()))
154                            && Arrays.equals(signature, m.getParameterTypes()))
155                        {
156                            method = m;
157                            break methodLoop;
158                        }
159                    }
160                    }
161                }
162
163                // Try legacy mode
164                if (method == null)
165                {
166                String tmp = name.toLowerCase().substring(METHOD_NAME_LENGTH);
167                    method = getClass().getMethod(METHOD_NAME_PREFIX + StringUtils.capitalize(tmp), signature);
168                }
169
170                this.methodCache.put(name, signature, method);
171            }
172
173            return method;
174        }
175
176        /**
177         * This overrides the default Action.doPerform() to execute the
178         * doEvent() method. If that fails, then it will execute the
179         * doPerform() method instead.
180         *
181         * @param pipelineData Turbine information.
182         * @throws Exception a generic exception.
183         */
184        @Override
185    public void doPerform(PipelineData pipelineData)
186                        throws Exception
187        {
188            ParameterParser pp = pipelineData.get(Turbine.class, ParameterParser.class);
189                executeEvents(pp, new Class<?>[]{ PipelineData.class }, new Object[]{ pipelineData });
190        }
191
192        /**
193         * This method should be called to execute the event based system.
194         *
195         * @param pp the parameter parser
196         * @param signature the signature of the method to call
197         * @param parameters the parameters for the method to call
198         *
199         * @throws Exception a generic exception.
200         */
201        protected void executeEvents(ParameterParser pp, Class<?>[] signature, Object[] parameters)
202                        throws Exception
203        {
204                // Name of the button.
205                String theButton = null;
206
207                String button = pp.convert(BUTTON);
208                String key = null;
209
210                // Loop through and find the button.
211                for (String k : pp)
212                {
213                        key = k;
214                        if (key.startsWith(button))
215                        {
216                                if (considerKey(key, pp))
217                                {
218                                        theButton = key;
219                                        break;
220                                }
221                        }
222                }
223
224                if (theButton == null)
225                {
226                    theButton = BUTTON + DEFAULT_METHOD;
227                    key = null;
228                }
229
230                theButton = formatString(theButton, pp);
231                Method method = null;
232
233        try
234        {
235            method = getMethod(theButton, signature, pp);
236        }
237        catch (NoSuchMethodException e)
238        {
239            method = getMethod(DEFAULT_METHOD, signature, pp);
240        }
241        finally
242        {
243            if (key != null)
244            {
245                pp.remove(key);
246            }
247        }
248
249                try
250                {
251                        if (log.isDebugEnabled())
252                        {
253                                log.debug("Invoking " + method);
254                        }
255
256                        method.invoke(this, parameters);
257                }
258                catch (InvocationTargetException ite)
259                {
260                        Throwable t = ite.getTargetException();
261                        if (bubbleUpException)
262                        {
263                if (t instanceof Exception)
264                {
265                    throw (Exception) t;
266                }
267                else
268                {
269                    throw ite;
270                }
271                        }
272                        else
273                        {
274                            log.error("Invokation of " + method , t);
275                        }
276                }
277        }
278
279        /**
280         * This method does the conversion of the lowercase method name
281         * into the proper case.
282         *
283         * @param input The unconverted method name.
284         * @param pp The parameter parser (for correct folding)
285         * @return A string with the method name in the proper case.
286         */
287        protected String formatString(String input, ParameterParser pp)
288        {
289                String tmp = input;
290
291                if (StringUtils.isNotEmpty(input))
292                {
293                        tmp = input.toLowerCase();
294
295                        // Chop off suffixes (for image type)
296                        String methodName = (tmp.endsWith(".x") || tmp.endsWith(".y"))
297                                        ? input.substring(0, input.length() - 2)
298                                        : input;
299
300                        if (pp.getUrlFolding() == URLCaseFolding.NONE)
301                        {
302                tmp = methodName.substring(BUTTON_LENGTH);
303                        }
304                        else
305                        {
306                tmp = methodName.toLowerCase().substring(BUTTON_LENGTH);
307                        }
308                }
309
310                return tmp;
311        }
312
313        /**
314         * Checks whether the selected key really is a valid event.
315         *
316         * @param key The selected key
317         * @param pp The parameter parser to look for the key value
318         *
319         * @return true if this key is really an ActionEvent Key
320         */
321        protected boolean considerKey(String key, ParameterParser pp)
322        {
323                if (!submitValueKey)
324                {
325                        log.debug("No Value required, accepting " + key);
326                        return true;
327                }
328                else
329                {
330                        // If the action.eventsubmit.needsvalue key is true,
331                        // events with a "0" or empty value are ignored.
332                        // This can be used if you have multiple eventSubmit_do&lt;xxx&gt;
333                        // fields in your form which are selected by client side code,
334                        // e.g. JavaScript.
335                        //
336                        // If this key is unset or missing, nothing changes for the
337                        // current behavior.
338                        //
339                        String keyValue = pp.getString(key);
340                        log.debug("Key Value is " + keyValue);
341                        if (StringUtils.isEmpty(keyValue))
342                        {
343                                log.debug("Key is empty, rejecting " + key);
344                                return false;
345                        }
346
347                        try
348                        {
349                                if (Integer.parseInt(keyValue) != 0)
350                                {
351                                        log.debug("Integer != 0, accepting " + key);
352                                        return true;
353                                }
354                        }
355                        catch (NumberFormatException nfe)
356                        {
357                                // Not a number. So it might be a
358                                // normal Key like "continue" or "exit". Accept
359                                // it.
360                                log.debug("Not a number, accepting " + key);
361                                return true;
362                        }
363                }
364                log.debug("Rejecting " + key);
365                return false;
366        }
367}