/**
 * Copyright 2007-2016, Kaazing Corporation. All rights reserved.
 *
 * 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 org.apache.mina.core.filterchain;

import org.apache.mina.core.session.IoSession;

/**
 * An interface that builds {@link IoFilterChain} in predefined way
 * when {@link IoSession} is created.  You can extract common filter chain
 * modification logic to this interface.  For example, to add a filter
 * to the chain,
 * <pre>
 * public class MyFilterChainBuilder implements IoFilterChainBuilder {
 *     public void buildFilterChain( IoFilterChain chain ) throws Exception {
 *         chain.addLast( "myFilter", new MyFilter() );
 *     }
 * }
 * </pre>
 *
 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
 */
public interface IoFilterChainBuilder {
    /**
     * An implementation which does nothing.
     */
    IoFilterChainBuilder NOOP = new IoFilterChainBuilder() {
        public void buildFilterChain(IoFilterChain chain) throws Exception {
        }

        @Override
        public String toString() {
            return "NOOP";
        }
    };

    /**
     * Modifies the specified <tt>chain</tt>.
     */
    void buildFilterChain(IoFilterChain chain) throws Exception;
}
