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    1   /*
    2    * $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/function/ContainsFunction.java,v 1.9 2005/06/28 13:44:45 elharo Exp $
    3    * $Revision: 1.9 $
    4    * $Date: 2005/06/28 13:44:45 $
    5    *
    6    * ====================================================================
    7    *
    8    * Copyright (C) 2000-2002 bob mcwhirter & James Strachan.
    9    * All rights reserved.
    10   *
    11   * Redistribution and use in source and binary forms, with or without
    12   * modification, are permitted provided that the following conditions
    13   * are met:
    14   *
    15   * 1. Redistributions of source code must retain the above copyright
    16   *    notice, this list of conditions, and the following disclaimer.
    17   *
    18   * 2. Redistributions in binary form must reproduce the above copyright
    19   *    notice, this list of conditions, and the disclaimer that follows
    20   *    these conditions in the documentation and/or other materials
    21   *    provided with the distribution.
    22   *
    23   * 3. The name "Jaxen" must not be used to endorse or promote products
    24   *    derived from this software without prior written permission.  For
    25   *    written permission, please contact license@jaxen.org.
    26   *
    27   * 4. Products derived from this software may not be called "Jaxen", nor
    28   *    may "Jaxen" appear in their name, without prior written permission
    29   *    from the Jaxen Project Management (pm@jaxen.org).
    30   *
    31   * In addition, we request (but do not require) that you include in the
    32   * end-user documentation provided with the redistribution and/or in the
    33   * software itself an acknowledgement equivalent to the following:
    34   *     "This product includes software developed by the
    35   *      Jaxen Project <http://www.jaxen.org/>."
    36   * Alternatively, the acknowledgment may be graphical using the logos
    37   * available at http://www.jaxen.org/
    38   *
    39   * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
    40   * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
    41   * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    42   * DISCLAIMED.  IN NO EVENT SHALL THE Jaxen AUTHORS OR THE PROJECT
    43   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
    44   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
    45   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
    46   * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
    47   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
    48   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
    49   * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
    50   * SUCH DAMAGE.
    51   *
    52   * ====================================================================
    53   * This software consists of voluntary contributions made by many
    54   * individuals on behalf of the Jaxen Project and was originally
    55   * created by bob mcwhirter <bob@werken.com> and
    56   * James Strachan <jstrachan@apache.org>.  For more information on the
    57   * Jaxen Project, please see <http://www.jaxen.org/>.
    58   *
    59   * $Id: ContainsFunction.java,v 1.9 2005/06/28 13:44:45 elharo Exp $
    60   */
    61
    62  package org.jaxen.function;
    63
    64  import java.util.List;
    65
    66  import org.jaxen.Context;
    67  import org.jaxen.Function;
    68  import org.jaxen.FunctionCallException;
    69  import org.jaxen.Navigator;
    70
    71  /***
    72   *  <p><b>4.2</b> <code><i>boolean</i> contains(<i>string</i>,<i>string</i>)</code></p>
    73   *
    74   * <blockquote src="http://www.w3.org/TR/xpath">
    75   * The <b>contains</b> function returns true if the first argument
    76   * string contains the second argument string, and otherwise returns false.
    77   * </blockquote>
    78   *
    79   * @author bob mcwhirter (bob @ werken.com)
    80   *
    81   * @see <a href="http://www.w3.org/TR/xpath#function-contains">Section 4.2 of the XPath Specification</a>
    82   */
    83  public class ContainsFunction implements Function
    84  {
    85
    86      /***
    87       * Create a new <code>ContainsFunction</code> object.
    88       */
    89      public ContainsFunction() {}
    90
    91      /***
    92       * <p>
    93       *  Returns true if the string-value of the
    94       *  first item in <code>args</code> contains string-value of the second
    95       *  item; false otherwise.
    96       *  If necessary one or both items are converted to a string as if by the XPath
    97       *  <code>string()</code> function.
    98       * </p>
    99       *
    100      * @param context the context at the point in the
    101      *         expression when the function is called
    102      * @param args a list containing exactly two items
    103      *
    104      * @return the result of evaluating the function;
    105      *     <code>Boolean.TRUE</code> or <code>Boolean.FALSE</code>
    106      *
    107      * @throws FunctionCallException if <code>args</code> does not have exactly two items
    108      */
    109     public Object call(Context context,
    110                        List args) throws FunctionCallException
    111     {
    112         if (args.size() == 2)
    113         {
    114             return evaluate(args.get(0),
    115                             args.get(1),
    116                             context.getNavigator() );
    117         }
    118
    119         throw new FunctionCallException("contains() requires two arguments.");
    120     }
    121
    122     /***
    123      * <p>Returns true if the first string contains the second string; false otherwise.
    124      * If necessary one or both arguments are converted to a string as if by the XPath
    125      * <code>string()</code> function.
    126      * </p>
    127      *
    128      * @param strArg the containing string
    129      * @param matchArg the contained string
    130      * @param nav used to calculate the string-values of the first two arguments
    131      *
    132      * @return <code>Boolean.TRUE</code> if true if the first string contains
    133      *     the second string; <code>Boolean.FALSE</code> otherwise.
    134      */
    135     public static Boolean evaluate(Object strArg,
    136                                    Object matchArg,
    137                                    Navigator nav)
    138     {
    139         String str   = StringFunction.evaluate( strArg,
    140                                                 nav );
    141
    142         String match = StringFunction.evaluate( matchArg,
    143                                                 nav );
    144
    145         return ( ( str.indexOf(match) >= 0)
    146                  ? Boolean.TRUE
    147                  : Boolean.FALSE
    148                  );
    149     }
    150 }