Milyn - Copyright (C) 2006 - 2010

  This library is free software; you can redistribute it and/or

  modify it under the terms of the GNU Lesser General Public

  License (version 2.1) as published by the Free Software

  Foundation.

  This library 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:

  http://www.gnu.org/licenses/lgpl.txt

*/

* DAO Updater

* <p />

* This DAO updater calls the update method of a DAO, using a entity bean from

* the bean context as parameter.

*

* <h3>Configuration</h3>

* <b>Namespace:</b> http://www.milyn.org/xsd/smooks/persistence-1.2.xsd<br>

* <b>Element:</b> updater<br>

* <b>Attributes:</b>

* <ul>

*  <li><b>beanId</b> : The id under which the entity bean is bound in the bean context. (<i>required</i>)

*  <li><b>updateOnElement</b> : The element selector to select the element when the inserter should execute. (<i>required</i>)

*   <li><b>dao</b> : The name of the DAO that will be used. If it is not set then the default DAO is used. (<i>optional</i>)

*  <li><b>name*</b> : The name of the update method. Depending of the adapter this can mean different things.

*                     For instance when using annotated DAO's you can name the methods and target them with this property, but

*                     when using the Ibatis adapter you set the id of the Ibatis statement in this attribute. (<i>optional</i>)

*  <li><b>updatedBeanId</b> : The bean id under which the updated bean will be stored. If not set then the object returned

*                              by the update method will not be stored in bean context. (<i>optional</i>)

*  <li><b>updateBefore</b> : If the updater should execute on the 'before' event. (<i>default: false</i>)

* </ul>

*

* <i>* This attribute is not supported by all scribe adapters.</i>

*

* <h3>Configuration Example</h3>

* <pre>

* &lt;?xml version=&quot;1.0&quot;?&gt;

* &lt;smooks-resource-list xmlns=&quot;http://www.milyn.org/xsd/smooks-1.1.xsd&quot;

*   xmlns:dao=&quot;http://www.milyn.org/xsd/smooks/persistence-1.2.xsd&quot;&gt;

*

*      &lt;dao:updater dao=&quot;dao&quot; name=&quot;updateIt&quot; beanId=&quot;toUpdate&quot; updateOnElement=&quot;root&quot; updateBeanId=&quot;updated&quot; updateBefore=&quot;false&quot; /&gt;

*

* &lt;/smooks-resource-list&gt;

* </pre>

*

* @author <a href="mailto:maurice.zeijen@smies.com">maurice.zeijen@smies.com</a>

*/

    private static Log logger = LogFactory.getLog(EntityUpdater.class);

    @ConfigParam(name = "beanId")

    private String beanIdName;

    @ConfigParam(name = "updatedBeanId", use = Use.OPTIONAL)

    private String updatedBeanIdName;

    @ConfigParam(name = "dao", use = Use.OPTIONAL)

    private String daoName;

    @ConfigParam(use = Use.OPTIONAL)

    private String name;

    @AppContext

    private ApplicationContext appContext;

    private ObjectStore objectStore;

    private BeanId beanId;

    private BeanId updatedBeanId;

    @Initialize

    public void initialize() throws SmooksConfigurationException {

      BeanIdStore beanIdStore = appContext.getBeanIdStore();

      beanId = beanIdStore.register(beanIdName);

      if(updatedBeanIdName != null) {

        updatedBeanId = beanIdStore.register(updatedBeanIdName);

      }

      objectStore = new ApplicationContextObjectStore(appContext);

    }

    /* (non-Javadoc)

   * @see org.milyn.delivery.ordering.Producer#getProducts()

   */

  public Set<? extends Object> getProducts() {

    if(updatedBeanIdName == null) {

      return Collections.emptySet();

    } else {

      return CollectionsUtil.toSet(updatedBeanIdName);

    }

  }

  /* (non-Javadoc)

   * @see org.milyn.delivery.ordering.Consumer#consumes(java.lang.String)

   */

  public boolean consumes(Object object) {

    return object.equals(beanIdName);

  }

    public void visitBefore(final Element element, final ExecutionContext executionContext) throws SmooksException {

      update(executionContext, new Fragment(element));

    }

    public void visitAfter(final Element element, final ExecutionContext executionContext) throws SmooksException {

      update(executionContext, new Fragment(element));

    }

    public void visitBefore(final SAXElement element, final ExecutionContext executionContext) throws SmooksException, IOException {

      update(executionContext, new Fragment(element));

    }

    public void visitAfter(final SAXElement element, final ExecutionContext executionContext) throws SmooksException, IOException {

      update(executionContext, new Fragment(element));

    }

  /**

   * @param executionContext

   * @param source

     * @return

   */

  @SuppressWarnings("unchecked")

  private void update(final ExecutionContext executionContext, Fragment source) {

    if(logger.isDebugEnabled()) {

      logger.debug("Updating bean under BeanId '" + beanIdName + "' with DAO '" + daoName + "'.");

    }

    BeanContext beanContext = executionContext.getBeanContext();

    Object bean = beanContext.getBean(beanId);

    final DaoRegister emr = PersistenceUtil.getDAORegister(executionContext);

    Object dao = null;

    try {

      if(daoName == null) {

        dao = emr.getDefaultDao();

      } else {

        dao = emr.getDao(daoName);

      }

      if(dao == null) {

        throw new IllegalStateException("The DAO register returned null while getting the DAO '" + daoName + "'");

      }

      final DaoInvoker daoInvoker = DaoInvokerFactory.getInstance().create(dao, objectStore);

      Object result = name == null ? daoInvoker.update(bean) : daoInvoker.update(name, bean) ;

      if(updatedBeanId != null) {

        if(result == null) {

          result = bean;

        }

        beanContext.addBean(updatedBeanId, result, source);

      } else if(result != null && bean != result) {

        beanContext.changeBean(beanId, bean, source);

      }

    } finally {

      if(dao != null) {

        emr.returnDao(dao);

      }

    }

  }

}