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
021package org.granite.tide.spring;
022
023import org.aspectj.lang.ProceedingJoinPoint;
024import org.aspectj.lang.annotation.Around;
025import org.aspectj.lang.annotation.Aspect;
026import org.granite.gravity.Gravity;
027import org.granite.logging.Logger;
028import org.granite.tide.data.DataContext;
029import org.granite.tide.data.DataEnabled;
030import org.granite.tide.data.DataEnabled.PublishMode;
031import org.granite.tide.data.DataUpdatePostprocessor;
032import org.springframework.beans.factory.annotation.Autowired;
033import org.springframework.core.Ordered;
034import org.springframework.transaction.support.TransactionSynchronizationAdapter;
035import 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
044public 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}