/*

  * Licensed to the Apache Software Foundation (ASF) under one

  * or more contributor license agreements. See the NOTICE file

  * distributed with this work for additional information

  * regarding copyright ownership. The ASF licenses this file

  * to you under the Apache 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.apache.org/licenses/LICENSE-2.0

  *

  * 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.apache.shindig.social.core.util;

 import java.util.Collection;

 import net.sf.json.JSONArray;

 import net.sf.json.JSONObject;

 import net.sf.json.util.PropertyFilter;

 /**

  * A property filter that rejects null values.

  */

 public class NullPropertyFilter implements PropertyFilter {

   /**

    * Filter the output of a property, if it should be emitted return false.

    * @param source The object containing the value

    * @param name the name of the key in the output structure

    * @param value the value of the object

    * @return true if the property should be filtered, false if not.

    */

   public boolean apply(Object source, String name, Object value) {

     if (value == null) {

       return true;

     }

     if (value instanceof JSONArray) {

       JSONArray array = (JSONArray) value;

       if (array.size() == 0) {

         return true;

       }

     }

     if (value instanceof JSONObject) {

       JSONObject object = (JSONObject) value;

       if (object.isNullObject() || object.isEmpty()) {

         return true;

       }

     }

     if (value instanceof Collection) {

       Collection<?> collection = (Collection<?>) value;

       if (collection.size() == 0) {

         return true;

       }

     }

     if (value instanceof Object[]) {

       Object[] oarray = (Object[]) value;

       if (oarray.length == 0) {

         return true;

       }

     }

     return false;

   }

 }