/*

  * Copyright 2007-2008 The Kuali Foundation

  * 

  * Licensed under the Educational Community License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  * 

  * http://www.opensource.org/licenses/ecl2.php

  * 

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 package org.kuali.rice.ken.util;

 import java.io.IOException;

 import java.util.Properties;

 import org.springframework.beans.factory.config.PropertyPlaceholderConfigurer;

 import org.springframework.core.io.FileSystemResourceLoader;

 import org.springframework.core.io.Resource;

 import org.springframework.util.DefaultPropertiesPersister;

 /**

  * PropertyPlaceholderConfigurer subclass that overrides any statically defined properties and properties locations,

  * with configuration settings from a properties file specified in a System property.

  * @see PropertyPlaceholderConfigurer

  * @author Kuali Rice Team (rice.collab@kuali.org)

  */

 public class NotificationPropertyPlaceholderConfigurer extends PropertyPlaceholderConfigurer {

     private static final String CFG_LOCATION_PROPERTY = "notification.config";

     /**

      * @see org.springframework.core.io.support.PropertiesLoaderSupport#mergeProperties()

      */

     @Override

     protected Properties mergeProperties() throws IOException {

         Properties properties = super.mergeProperties();

         return transformProperties(properties);

     }

     /**

      * This method consolidates config properties.

      * @param properties

      * @return Properties

      * @throws IOException

      */

     protected Properties transformProperties(Properties properties) throws IOException {

         String cfgLocation = System.getProperty(CFG_LOCATION_PROPERTY);

         if (cfgLocation != null) {

             Resource resource = new FileSystemResourceLoader().getResource(cfgLocation);

             if (resource != null && resource.exists()) {

                 new DefaultPropertiesPersister().load(properties, resource.getInputStream());

             }

         }

         return properties;

     }

     /* I would have liked to just dynamically add a new Resource to the list of resource locations and

      * delegate entirely to the superclass hierarchy for loading, but unfortunately the locations member

      * is inaccessible, so we have to load the properties into the existing properties object ourselves,

      * in the process overridding any existing entries

      */

 //    public void afterPropertiesSet() throws Exception {

 //        String cfg = System.getProperty(CFG_LOCATION_PROPERTY);

 //        if (cfg == null) return;

 //        

 //        Resource resource = new FileSystemResourceLoader().getResource(cfg);

 //        // add resource to locations

 //    }

 }