/*

  * Copyright 2004-2011 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.teeda.core.convert;

 import javax.faces.component.StateHolder;

 import javax.faces.component.UIComponent;

 import javax.faces.context.FacesContext;

 import javax.faces.convert.Converter;

 import javax.faces.convert.ConverterException;

 /**

  * @author higa

  *

  */

 public class NullConverter implements Converter, StateHolder {

     private static final String[] DEFAULT_NULL_VALUES = new String[] { "", "on" };

     private String[] nullValues = DEFAULT_NULL_VALUES;

     private boolean transientValue;

     public String[] getNullValues() {

         return nullValues;

     }

     public void setNullValues(String[] nullValues) {

         this.nullValues = nullValues;

     }

     /**

      * @see javax.faces.convert.Converter#getAsObject(javax.faces.context.FacesContext, javax.faces.component.UIComponent, java.lang.String)

      */

     public Object getAsObject(FacesContext context, UIComponent component,

             String value) throws ConverterException {

         for (int i = 0; i < nullValues.length; ++i) {

             if (nullValues[i].equalsIgnoreCase(value)) {

                 return null;

             }

         }

         return value;

     }

     /**

      * @see javax.faces.convert.Converter#getAsString(javax.faces.context.FacesContext, javax.faces.component.UIComponent, java.lang.Object)

      */

     public String getAsString(FacesContext context, UIComponent component,

             Object value) throws ConverterException {

         if (value == null) {

             return "";

         }

         return value.toString();

     }

     /**

      * @see javax.faces.component.StateHolder#saveState(javax.faces.context.FacesContext)

      */

     public Object saveState(FacesContext context) {

         Object[] values = new Object[1];

         values[0] = nullValues;

         return values;

     }

     /**

      * @see javax.faces.component.StateHolder#restoreState(javax.faces.context.FacesContext, java.lang.Object)

      */

     public void restoreState(FacesContext context, Object state) {

         Object[] values = (Object[]) state;

         nullValues = (String[]) values[0];

     }

     /**

      * @see javax.faces.component.StateHolder#isTransient()

      */

     public boolean isTransient() {

         return transientValue;

     }

     /**

      * @see javax.faces.component.StateHolder#setTransient(boolean)

      */

     public void setTransient(boolean transientValue) {

         this.transientValue = transientValue;

     }

 }