TideDataPublishingInterceptor.java

/**
 *   GRANITE DATA SERVICES
 *   Copyright (C) 2006-2015 GRANITE DATA SERVICES S.A.S.
 *
 *   This file is part of the Granite Data Services Platform.
 *
 *   Granite Data Services is free software; you can redistribute it and/or
 *   modify it under the terms of the GNU Lesser General Public
 *   License as published by the Free Software Foundation; either
 *   version 2.1 of the License, or (at your option) any later version.
 *
 *   Granite Data Services is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
 *   General Public License for more details.
 *
 *   You should have received a copy of the GNU Lesser General Public
 *   License along with this library; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
 *   USA, or see <http://www.gnu.org/licenses/>.
 */
package org.granite.tide.cdi;

import javax.enterprise.event.Event;
import javax.enterprise.inject.Instance;
import javax.inject.Inject;
import javax.interceptor.AroundInvoke;
import javax.interceptor.Interceptor;
import javax.interceptor.InvocationContext;

import org.granite.gravity.Gravity;
import org.granite.tide.data.DataContext;
import org.granite.tide.data.DataEnabled;
import org.granite.tide.data.DataEnabled.PublishMode;
import org.granite.tide.data.DataTopicParams;
import org.granite.tide.data.DataUpdatePostprocessor;


/**
 * CDI interceptor to handle publishing of data changes instead of relying on the default behaviour
 * This can be used outside of a HTTP Granite context and should be applied inside the security/transaction context
 * 
 * @author William DRAI
 */
@DataEnabled(topic="", params=DataTopicParams.class, publish=PublishMode.MANUAL, useInterceptor=true)
@Interceptor
public class TideDataPublishingInterceptor {
	
	@Inject
	private Gravity gravity;
	
	@Inject
	private Instance<DataUpdatePostprocessor> dataUpdatePostprocessor;
	
	@Inject
	private Event<TideDataPublishingEvent> dataPublishingEvent;
	
    @AroundInvoke
    public Object processPublishData(InvocationContext invocationContext) throws Throwable {
    	DataEnabled dataEnabled = invocationContext.getMethod().getDeclaringClass().getAnnotation(DataEnabled.class);
    	if (dataEnabled == null || dataEnabled.topic().equals("") || !dataEnabled.useInterceptor())
    		return invocationContext.proceed();
    	
    	boolean shouldRemoveContextAtEnd = DataContext.get() == null;
    	boolean shouldInitContext = shouldRemoveContextAtEnd || DataContext.isNull();
    	boolean onCommit = false;
    	
    	if (shouldInitContext) {
    		DataContext.init(gravity, dataEnabled.topic(), dataEnabled.params(), dataEnabled.publish());
    		
    		if (!dataUpdatePostprocessor.isUnsatisfied())
    			DataContext.get().setDataUpdatePostprocessor(dataUpdatePostprocessor.get());
    	}
    	
        DataContext.observe();
        try {
        	if (dataEnabled.publish().equals(PublishMode.ON_COMMIT)) {
        		dataPublishingEvent.fire(new TideDataPublishingEvent(shouldRemoveContextAtEnd));
        		onCommit = true;
        	}
        	
        	Object ret = invocationContext.proceed();
        	
        	DataContext.publish(PublishMode.ON_SUCCESS);
        	return ret;
        }
        finally {
        	if (shouldRemoveContextAtEnd && !onCommit)
        		DataContext.remove();
        }
    }
}