/**
 * Redistribution and use of this software and associated documentation ("Software"), with or
 * without modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain copyright statements and notices. Redistributions
 * must also contain a copy of this document.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of
 * conditions and the following disclaimer in the documentation and/or other materials provided with
 * the distribution.
 *
 * 3. The name "Exolab" must not be used to endorse or promote products derived from this Software
 * without prior written permission of Intalio, Inc. For written permission, please contact
 * info@exolab.org.
 *
 * 4. Products derived from this Software may not be called "Exolab" nor may "Exolab" appear in
 * their names without prior written permission of Intalio, Inc. Exolab is a registered trademark of
 * Intalio, Inc.
 *
 * 5. Due credit should be given to the Exolab Project (http://www.exolab.org/).
 *
 * THIS SOFTWARE IS PROVIDED BY INTALIO, INC. AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESSED OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL INTALIO, INC. OR ITS
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
 * WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Copyright 2000 (C) Intalio, Inc. All Rights Reserved.
 *
 * $Id$
 */

package org.exolab.castor.util;

import org.apache.regexp.*;
import org.castor.core.util.Messages;

/**
 * An implementation of {@link RegExpEvaluator} that uses the Jakarta Regular Expression library.
 * For more information about the Jakarta RE library please visit:
 * <a href="http://jakarta.apache.org/regexp/"> http://jakarta.apache.org/regexp/</a>
 * 
 * @author <a href="mailto:kvisco@intalio.com">Keith Visco</a>
 * @version $Revision$ $Date: 2004-02-14 02:16:35 -0700 (Sat, 14 Feb 2004) $
 */
public class JakartaRegExpEvaluator implements RegExpEvaluator {

  /**
   * Reguar expression denoting a beginning of line.
   */
  private static final String BOL = "^(";

  /**
   * Regular expression denoting end of line.
   */
  private static final String EOL = ")$";

  /**
   * The Regular expression
   */
  private RE _regexp;

  /**
   * {@inheritDoc}
   * 
   * @see org.exolab.castor.util.RegExpEvaluator#setExpression(java.lang.String)
   */
  public void setExpression(final String rexpr) {

    if (rexpr != null) {
      try {
        // -- patch and compile expression
        _regexp = new RE(BOL + rexpr + EOL);
      } catch (RESyntaxException ex) {
        String message = Messages.format("regexp.eval.error", rexpr);
        throw new IllegalArgumentException(message, ex);
      }
    } else {
      _regexp = null;
    }
  }

  /**
   * {@inheritDoc}
   * 
   * @see org.exolab.castor.util.RegExpEvaluator#matches(java.lang.String)
   */
  public boolean matches(final String value) {
    if (_regexp != null) {
      return _regexp.match(value);
    }
    return true;
  }

}
