/*

  * 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.validator.Validator;

 import javax.servlet.jsp.JspException;

 /**

  * This is the base Tag for all ValidatorTags which got a minimum and a maimum attribute.

  * 

  * @author Andreas Berger (latest modification by $Author$)

  * @version $Revision$ $Date$

  * @since 1.2

  */

 public abstract class GenericMinMaxValidatorTag<T> extends ValidatorTag

 {

     protected ValueExpression _minimum;

     protected ValueExpression _maximum;

     protected T _min = null;

     protected T _max = null;

     public void setMinimum(ValueExpression minimum)

     {

         _minimum = minimum;

     }

     public void setMaximum(ValueExpression maximum)

     {

         _maximum = maximum;

     }

     @Override

     public void release()

     {

         _minimum = null;

         _maximum = null;

         _min = null;

         _max = null;

     }

     /**

      * This method returns the Validator, you have to cast it to the correct type and apply the min and max values.

      * 

      * @return

      * @throws JspException

      */

     @Override

     protected Validator createValidator() throws JspException

     {

         if (null == _minimum && null == _maximum)

         {

             throw new JspException("a minimum and / or a maximum have to be specified");

         }

         ELContext elContext = FacesContext.getCurrentInstance().getELContext();

         if (null != _minimum)

         {

             _min = getValue(_minimum.getValue(elContext));

         }

         if (null != _maximum)

         {

             _max = getValue(_maximum.getValue(elContext));

         }

         if (null != _minimum && null != _maximum)

         {

             if (!isMinLTMax())

             {

                 throw new JspException("maximum limit must be greater than the minimum limit");

             }

         }

         return super.createValidator();

     }

     /**

      * @return true if min is lower than max

      */

     protected abstract boolean isMinLTMax();

     /**

      * Wrapper method.

      * 

      * @param value

      * @return

      */

     protected abstract T getValue(Object value);

 }