/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.myfaces.taglib.core;
  
  import javax.el.ELContext;
  import javax.el.ValueExpression;
  import javax.faces.context.FacesContext;
  import javax.faces.convert.Converter;
  import javax.faces.webapp.ConverterELTag;
  import javax.servlet.jsp.JspException;
  
  /**
   * Implementation of ConverterELTag
   * 
   * @author Bruno Aranda (latest modification by $Author$)
   * @version $Revision$ $Date$
   */
  public class ConverterTag extends ConverterELTag
  {
  
      private static final long serialVersionUID = -4506829108081L;
      private ValueExpression _converterId;
      private ValueExpression _binding;
      private String _converterIdString = null;
  
      public ConverterTag()
      {
          super();
      }
  
      public void setConverterId(ValueExpression converterId)
      {
          _converterId = converterId;
      }
  
      public void setBinding(ValueExpression binding)
      {
          _binding = binding;
      }
  
      /**
       * Use this method to specify the converterId programmatically.
       * 
       * @param converterIdString
       */
      public void setConverterIdString(String converterIdString)
      {
          _converterIdString = converterIdString;
      }
  
      @Override
      public void release()
      {
          super.release();
          _converterId = null;
          _binding = null;
          _converterIdString = null;
      }
  
      @Override
      protected Converter createConverter() throws JspException
      {
          Converter converter = null;
  
          FacesContext facesContext = FacesContext.getCurrentInstance();
          ELContext elContext = facesContext.getELContext();
  
          // try to create the converter from the binding expression first, and then from
          // the converterId
          if (_binding != null)
          {
              try
              {
                  converter = (Converter)_binding.getValue(elContext);
  
                  if (converter != null)
                  {
                      return converter;
                  }
              }
              catch (Exception e)
              {
                  throw new JspException("Exception creating converter using binding", e);
             }
         }
 
         if ((_converterId != null) || (_converterIdString != null))
         {
             try
             {
                 if (null != _converterIdString)
                 {
                     converter = facesContext.getApplication().createConverter(_converterIdString);
                 }
                 else
                 {
                     String converterId = (String)_converterId.getValue(elContext);
                     converter = facesContext.getApplication().createConverter(converterId);
                 }
 
                 // with binding no converter was created, set its value with the converter
                 // created using the converterId
                 if (converter != null && _binding != null)
                 {
                     _binding.setValue(elContext, converter);
                 }
             }
             catch (Exception e)
             {
                 throw new JspException("Exception creating converter with converterId: " + _converterId, e);
             }
         }
         
         if (converter == null)
         {
             throw new JspException("Could not create converter. Please specify a valid converterId" +
                     " or a non-null binding.");
         }
 
         return converter;
     }
 
 }