Copyright 2014 Netflix, Inc.
Licensed 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.
/**
 * Copyright 2014 Netflix, Inc.
 *
 * Licensed 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 com.netflix.config;

An abstract PropertyListener for use by different components who need to listen for configuration changes. Users only need to implement the handlePropertyEvent(String, Object, EventType) method. 
Author:
pkamath/**
 * An abstract {@link PropertyListener} for use by different
 * components who need to listen for configuration changes. Users only need to
 * implement the {@link #handlePropertyEvent(String, Object, EventType)} method.
 * 
 * @author pkamath
 */
public abstract class AbstractDynamicPropertyListener implements  PropertyListener {

    public enum EventType {
        ADD, SET, CLEAR
    };
    
    
    @Override
    public void addProperty(Object source, String name, Object value,
            boolean beforeUpdate) {
        if (!beforeUpdate) {
            handlePropertyEvent(name, value, EventType.ADD);
        }
    }

    @Override
    public void clear(Object source, boolean beforeUpdate) {
        // no op - only interested in adds, sets and clears at a property leve!
    }

    @Override
    public void clearProperty(Object source, String name, Object value,
            boolean beforeUpdate) {
        if (!beforeUpdate) {
            handlePropertyEvent(name, value, EventType.CLEAR);
        }
    }

    @Override
    public void configSourceLoaded(Object source) {
        // no op - only interested in adds, sets and clears!
    }

    @Override
    public void setProperty(Object source, String name, Object value,
            boolean beforeUpdate) {
        if (!beforeUpdate) {
            handlePropertyEvent(name, value, EventType.SET);
        }
    }

    public abstract void handlePropertyEvent(String name, Object value,
            EventType eventType);
    
}