/*
    * 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.application.Application;
  import javax.faces.context.FacesContext;
  import javax.faces.validator.RequiredValidator;
  import javax.faces.validator.Validator;
  import javax.faces.webapp.ValidatorELTag;
  import javax.servlet.jsp.JspException;
  
  /**
   * JSP Tag class for {@link javax.faces.validator.RequiredValidator}.
   *
   * @author Leonardo Uribe
   * @since 2.0
   */
  public class ValidateRequiredTag extends ValidatorELTag
  {
      /**
       * 
       */
      private static final long serialVersionUID = 6569308536432242026L;
          
      private ValueExpression _binding;
      
      public void setBinding(ValueExpression binding)
      {
          _binding = binding;
      }
  
      @Override
      public void release()
      {
          _binding = null;
      }
      
      @Override
      protected Validator createValidator() throws JspException
      {
          FacesContext facesContext = FacesContext.getCurrentInstance();
          ELContext elContext = facesContext.getELContext();
          if (null != _binding)
          {
              Object validator;
              try
              {
                  validator = _binding.getValue(elContext);
              }
              catch (Exception e)
              {
                  throw new JspException("Error while creating the Validator", e);
              }
              if (validator instanceof RequiredValidator)
              {
                  return (Validator)validator;
              }
          }
          Application application = facesContext.getApplication();
          RequiredValidator validator = null;
          try
          {
              validator = (RequiredValidator) application.createValidator(RequiredValidator.VALIDATOR_ID);
          }
          catch (Exception e)
          {
              throw new JspException("Error while creating the Validator", e);
          }
  
          if (null != validator)
          {
              if (null != _binding)
              {
                  _binding.setValue(elContext, validator);
              }            
          }
          return validator;
      }
  }