001    /*
002      GRANITE DATA SERVICES
003      Copyright (C) 2011 GRANITE DATA SERVICES S.A.S.
004    
005      This file is part of Granite Data Services.
006    
007      Granite Data Services is free software; you can redistribute it and/or modify
008      it under the terms of the GNU Library General Public License as published by
009      the Free Software Foundation; either version 2 of the License, or (at your
010      option) any later version.
011    
012      Granite Data Services is distributed in the hope that it will be useful, but
013      WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
014      FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
015      for more details.
016    
017      You should have received a copy of the GNU Library General Public License
018      along with this library; if not, see <http://www.gnu.org/licenses/>.
019    */
020    
021    package org.granite.tide.spring;
022    
023    import org.aspectj.lang.ProceedingJoinPoint;
024    import org.aspectj.lang.annotation.Around;
025    import org.aspectj.lang.annotation.Aspect;
026    import org.granite.gravity.Gravity;
027    import org.granite.logging.Logger;
028    import org.granite.tide.data.DataContext;
029    import org.granite.tide.data.DataEnabled;
030    import org.granite.tide.data.DataEnabled.PublishMode;
031    import org.granite.tide.data.DataUpdatePostprocessor;
032    import org.springframework.beans.factory.annotation.Autowired;
033    import org.springframework.core.Ordered;
034    import org.springframework.transaction.support.TransactionSynchronizationAdapter;
035    import org.springframework.transaction.support.TransactionSynchronizationManager;
036    
037    /**
038     * Spring AOP AspectJ aspect to handle publishing of data changes instead of relying on the default behaviour
039     * This can be used outside of a HTTP Granite context and inside the security/transaction context
040     *  
041     * @author William DRAI
042     */
043    @Aspect
044    public class TideDataPublishingAspect implements Ordered {
045            
046            private static final Logger log = Logger.getLogger(TideDataPublishingAspect.class);
047    
048            private int order = 0;
049            private Gravity gravity;
050            private DataUpdatePostprocessor dataUpdatePostprocessor;
051            
052            public void setGravity(Gravity gravity) {
053                    this.gravity = gravity;
054            }
055            
056            @Autowired(required=false)
057            public void setDataUpdatePostprocessor(DataUpdatePostprocessor dataUpdatePostprocessor) {
058                    this.dataUpdatePostprocessor = dataUpdatePostprocessor;
059            }
060    
061        public int getOrder() {
062            return order;
063        }
064        public void setOrder(int order) {
065            this.order = order;
066        }
067            
068            @Around("@within(dataEnabled)")
069        public Object invoke(ProceedingJoinPoint pjp, DataEnabled dataEnabled) throws Throwable {
070            if (dataEnabled == null || !dataEnabled.useInterceptor())
071                    return pjp.proceed();
072            
073            boolean shouldRemoveContextAtEnd = DataContext.get() == null;
074            boolean shouldInitContext = shouldRemoveContextAtEnd || DataContext.isNull();
075            boolean onCommit = false;
076            
077            if (shouldInitContext) {
078                    DataContext.init(gravity, dataEnabled.topic(), dataEnabled.params(), dataEnabled.publish());
079                    if (dataUpdatePostprocessor != null)
080                            DataContext.get().setDataUpdatePostprocessor(dataUpdatePostprocessor);
081            }
082            
083            DataContext.observe();
084            try {
085                    if (dataEnabled.publish().equals(PublishMode.ON_COMMIT) && !TransactionSynchronizationManager.isCurrentTransactionReadOnly()) {
086                             if (TransactionSynchronizationManager.isSynchronizationActive()) {
087                                     TransactionSynchronizationManager.registerSynchronization(new DataPublishingTransactionSynchronization(shouldRemoveContextAtEnd));
088                                     onCommit = true;
089                             }
090                             else
091                                     log.warn("Could not register synchronization for ON_COMMIT publish mode, check that the Spring PlatformTransactionManager supports it");
092                    }
093                    
094                    Object ret = pjp.proceed();
095                    
096                    DataContext.publish(PublishMode.ON_SUCCESS);
097                    return ret;
098            }
099            finally {
100                    if (shouldRemoveContextAtEnd && !onCommit)
101                            DataContext.remove();
102            }
103        }
104        
105        private static class DataPublishingTransactionSynchronization extends TransactionSynchronizationAdapter {
106            
107            private boolean removeContext = false;
108            
109            public DataPublishingTransactionSynchronization(boolean removeContext) {
110                    this.removeContext = removeContext;
111            }
112    
113                    @Override
114                    public void beforeCommit(boolean readOnly) {
115                            if (!readOnly)
116                                    DataContext.publish(PublishMode.ON_COMMIT);
117                    }
118    
119                    @Override
120                    public void beforeCompletion() {
121                            if (removeContext)
122                                    DataContext.remove();
123                    }       
124        }
125    }