content: /*
   * $Header$
   * $Revision$
   * $Date$
   *
   * ====================================================================
   *
   * Copyright 2000-2002 bob mcwhirter & James Strachan.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are
   * met:
   * 
   *   * Redistributions of source code must retain the above copyright
   *     notice, this list of conditions and the following disclaimer.
   * 
   *   * 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.
   * 
   *   * Neither the name of the Jaxen Project nor the names of its
   *     contributors may be used to endorse or promote products derived 
   *     from this software without specific prior written permission.
   * 
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
   * IS" AND ANY EXPRESS 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 THE COPYRIGHT OWNER
   * OR 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.
   *
   * ====================================================================
   * This software consists of voluntary contributions made by many 
   * individuals on behalf of the Jaxen Project and was originally 
   * created by bob mcwhirter <bob@werken.com> and 
   * James Strachan <jstrachan@apache.org>.  For more information on the 
   * Jaxen Project, please see <http://www.jaxen.org/>.
   * 
   * $Id$
   */
  
  
  package org.jaxen.function;
  
  import java.util.List;
  
  import org.jaxen.Context;
  import org.jaxen.Function;
  import org.jaxen.FunctionCallException;
  import org.jaxen.Navigator;
  
  /**
   * <p><b>4.2</b> <code><i>string</i> substring-after(<i>string</i>,<i>string</i>)</code></p> 
   * 
   * 
   * <blockquote src="http://www.w3.org/TR/xpath">
   * The <b>substring-after</b> function returns the substring of the first argument string 
   * that follows the first occurrence of the second argument string in the first 
   * argument string, or the empty string if the first argument string does not contain the second argument string. 
   * For example, substring-after("1999/04/01","/") returns 04/01, 
   * and substring-after("1999/04/01","19") returns 99/04/01.
   * </blockquote>
   * 
   * @author bob mcwhirter (bob @ werken.com)
   * @see <a href="http://www.w3.org/TR/xpath#function-substring-after" target="_top">Section 4.2 of the XPath Specification</a>
   */
  public class SubstringAfterFunction implements Function
  {
  
      /**
       * Create a new <code>SubstringAfterFunction</code> object.
       */
      public SubstringAfterFunction() {}
  
  
      /** 
       * Returns the part of the string-value of the first item in <code>args</code>
       * that follows the string-value of the second item in <code>args</code>;
       * or the empty string if the second string is not a substring of the first string.
       *
       * @param context the context at the point in the
       *         expression when the function is called
       * @param args a list that contains two items
       * 
       * @return a <code>String</code> containing that 
       *     part of the string-value of the first item in <code>args</code>
       *     that comes before the string-value of the second item in <code>args</code>
       * 
       * @throws FunctionCallException if <code>args</code> does not have length two
       */
      public Object call(Context context,
                         List args) throws FunctionCallException
      {
          if (args.size() == 2)
          {
              return evaluate( args.get(0),
                               args.get(1),
                               context.getNavigator() );
          }
  
          throw new FunctionCallException( "substring-after() requires two arguments." );
      }
  
  
      /** 
       * Returns the part of <code>strArg</code> that follows the first occurence 
       * of <code>matchArg</code>; or the empty string if the 
       * <code>strArg</code> does not contain <code>matchArg</code>
       * 
       * @param strArg the string from which the substring is extracted
       * @param matchArg the string that marks the boundary of the substring
       * @param nav the <code>Navigator</code> used to calculate the string-values of
       *     the first two arguments
       * 
       * @return a <code>String</code> containing
       *     the part of <code>strArg</code> that precedes the first occurence 
       *     of <code>matchArg</code>
       * 
       */
      public static String evaluate(Object strArg,
                                    Object matchArg,
                                    Navigator nav)
      {
          String str   = StringFunction.evaluate( strArg,
                                                  nav );
  
          String match = StringFunction.evaluate( matchArg,
                                                  nav );
      
          int loc = str.indexOf(match);
  
          if ( loc < 0 )
          {
              return "";
          }
  
          return str.substring(loc+match.length());
      }
  }
  