EDIT

/**

* Copyright (C) 2017 EDIT

* European Distributed Institute of Taxonomy

* http://www.e-taxonomy.eu

*

* The contents of this file are subject to the Mozilla Public License Version 1.1

* See LICENSE.TXT at the top of this package for the full license terms.

*/

package eu.etaxonomy.vaadin.mvp;

import org.hibernate.Session;

import org.springframework.context.event.EventListener;

import org.springframework.transaction.TransactionStatus;

import com.vaadin.data.fieldgroup.BeanFieldGroup;

import com.vaadin.data.fieldgroup.FieldGroup.CommitEvent;

import com.vaadin.data.util.BeanItem;

import eu.etaxonomy.cdm.model.common.CdmBase;

import eu.etaxonomy.cdm.vaadin.event.EntityChangeEvent;

import eu.etaxonomy.cdm.vaadin.event.EntityChangeEvent.Type;

/**

 * @author a.kohlbecker

 * @since Apr 5, 2017

 *

 */

public abstract class AbstractCdmEditorPresenter<DTO extends CdmBase> extends AbstractEditorPresenter<DTO> {

    private static final long serialVersionUID = 2218185546277084261L;

    TransactionStatus tx = null;

    @Override

    @EventListener

    public void onEditorPreSaveEvent(EditorPreSaveEvent preSaveEvent){

        tx = getRepo().startTransaction(true);

        // merge the bean and update the fieldGroup with the merged bean, so that updating

        // of field values in turn of the commit are can not cause LazyInitializationExeptions

        // the bean still has the original values at this point

        mergedBean(preSaveEvent.getCommitEvent());

    }

    @Override

    @EventListener

    public void onEditorSaveEvent(EditorSaveEvent saveEvent){

        // the bean is now updated with the changes made by the user

        // merge the bean into the session, ...

        DTO bean = mergedBean(saveEvent.getCommitEvent());

        Type changeEventType;

        if(bean.getId() > 1){

            changeEventType = Type.MODIFIED;

        } else {

            changeEventType = Type.CREATED;

        }

        getRepo().getCommonService().saveOrUpdate(bean);

        getSession().flush();

        getRepo().commitTransaction(tx);

        tx = null;

        eventBus.publishEvent(new EntityChangeEvent(bean.getClass(), bean.getId(), changeEventType));

    }

    /**

     * Obtains the bean from the fieldGroup, merges the bean into the session and

     * updates the fieldGroup with the merged bean.

     *

     * @param CommitEvent

     * @return The bean merged to the session

     */

    private DTO mergedBean(CommitEvent commitEvent) {

        // using just some service to get hold of the session

        Session session = getSession();

        @SuppressWarnings("unchecked")

        BeanItem<DTO> itemDataSource = ((BeanFieldGroup<DTO>)commitEvent.getFieldBinder()).getItemDataSource();

        DTO bean = itemDataSource.getBean();

        // evict bean before merge to avoid duplicate beans in same session

        session.evict(bean);

        @SuppressWarnings("unchecked")

        DTO mergedBean = (DTO) session.merge(bean);

        itemDataSource.setBean(mergedBean);

        return mergedBean;

    }

    /**

     * @return

     */

    private Session getSession() {

        return getRepo().getUserService().getSession();

    }

    @Override

    protected final void saveBean(DTO bean){

        // blank implementation, since this is not needed in this or any sub class

    }

}