/*

  * Copyright 2004-2008 the Seasar Foundation and the Others.

  *

  * 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.seasar.uruma.binding.value.binder;

 import org.seasar.framework.beans.BeanDesc;

 import org.seasar.framework.beans.PropertyDesc;

 import org.seasar.framework.beans.factory.BeanDescFactory;

 import org.seasar.uruma.binding.value.ValueBinder;

 import org.seasar.uruma.component.UIComponent;

 import org.seasar.uruma.util.AssertionUtil;

 /**

  * 汎用的な {@link ValueBinder} です。

  * 

  * @param <WIDGET_TYPE>

  *            対応するウィジットの型

  * @author y-komori

  */

 public class GenericValueBinder<WIDGET_TYPE> extends

         AbstractValueBinder<WIDGET_TYPE> {

     private PropertyDesc propertyDesc;

     /**

      * {@link GenericValueBinder} を構築します。<br />

      * 

      * @param targetClass

      *            ターゲットのクラスオブジェクト

      * @param propertyName

      *            ターゲットのプロパティ名称

      */

     public GenericValueBinder(final Class<WIDGET_TYPE> targetClass,

             final String propertyName) {

         super(targetClass);

         AssertionUtil.assertNotEmpty("propertyName", propertyName);

         BeanDesc beanDesc = BeanDescFactory.getBeanDesc(targetClass);

         this.propertyDesc = beanDesc.getPropertyDesc(propertyName);

     }

     /*

      * @see org.seasar.uruma.binding.value.binder.AbstractValueBinder#doImportValue(java.lang.Object,

      *      java.lang.Object, org.seasar.framework.beans.PropertyDesc)

      */

     @Override

     public void doImportValue(final WIDGET_TYPE widget, final Object formObj,

             final PropertyDesc propDesc, final UIComponent uiComp) {

         Object value = propertyDesc.getValue(widget);

         // 空文字列の入力は null として扱う

         if (value instanceof String && ((String) value).length() == 0) {

             value = null;

         }

         logBinding(IMPORT_VALUE, widget, propertyDesc, formObj, propDesc, value);

         propDesc.setValue(formObj, value);

     }

     /*

      * @see org.seasar.uruma.binding.value.binder.AbstractValueBinder#doExportValue(java.lang.Object,

      *      java.lang.Object, org.seasar.framework.beans.PropertyDesc)

      */

     @Override

     public void doExportValue(final WIDGET_TYPE widget, final Object formObj,

             final PropertyDesc propDesc, final UIComponent uiComp) {

         Object value = propDesc.getValue(formObj);

         if (value == null) {

             value = "";

         }

         logBinding(EXPORT_VALUE, formObj, propDesc, widget, propertyDesc, value);

         propertyDesc.setValue(widget, value);

     }

 }