// Copyright 2008 Thiago H. de Paula Figueiredo

 //

 // 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 br.com.arsmachina.tapestrycrud.services.impl;

 import java.io.Serializable;

 import org.apache.tapestry5.EventContext;

 import org.apache.tapestry5.PrimaryKeyEncoder;

 import br.com.arsmachina.tapestrycrud.encoder.ActivationContextEncoder;

 /**

  * An {@link ActivationContextEncoder} implementation based in a {@link PrimaryKeyEncoder}.

  * 

  * @author Thiago H. de Paula Figueiredo

  * @param <T> the entity class related to this DAO.

  * @param <K> the type of the field that represents the entity class' primary key.

  */

 class PrimaryKeyEncoderActivationContextEncoder<T, K extends Serializable> implements

                 ActivationContextEncoder<T> {

         final private Class<K> primaryKeyType;

         final private PrimaryKeyEncoder<K, T> primaryKeyEncoder;

         /**

          * @param primaryKeyType

          */

         @SuppressWarnings("unchecked")

         public PrimaryKeyEncoderActivationContextEncoder(PrimaryKeyEncoder<K, T> primaryKeyEncoder,

                         Class<K> primaryKeyType) {

                 if (primaryKeyType == null) {

                         throw new IllegalArgumentException("Parameter primaryKeyType cannot be null");

                 }

                 if (primaryKeyEncoder == null) {

                         throw new IllegalArgumentException("Parameter primaryKeyEncoder cannot be null");

                 }

                 this.primaryKeyEncoder = primaryKeyEncoder;

                 this.primaryKeyType = primaryKeyType;

         }

         /**

          * @see br.com.arsmachina.tapestrycrud.encoder.ActivationContextEncoder#toActivationContext(java.lang.Object)

          */

         public Object toActivationContext(T object) {

                 return primaryKeyEncoder.toKey(object);

         }

         /**

          * @see br.com.arsmachina.tapestrycrud.encoder.ActivationContextEncoder#toObject(org.apache.tapestry5.EventContext)

          */

         public T toObject(EventContext value) {

                 return primaryKeyEncoder.toValue(value.get(primaryKeyType, 0));

         }

 }