1 /*
2 * $Header$
3 * $Revision$
4 * $Date$
5 *
6 * ====================================================================
7 *
8 * Copyright 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 are
13 * met:
14 *
15 * * Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 *
18 * * Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 *
22 * * Neither the name of the Jaxen Project nor the names of its
23 * contributors may be used to endorse or promote products derived
24 * from this software without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
27 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
29 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
30 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
31 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
32 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
33 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
34 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
35 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
36 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
37 *
38 * ====================================================================
39 * This software consists of voluntary contributions made by many
40 * individuals on behalf of the Jaxen Project and was originally
41 * created by bob mcwhirter <bob@werken.com> and
42 * James Strachan <jstrachan@apache.org>. For more information on the
43 * Jaxen Project, please see <http://www.jaxen.org/>.
44 *
45 * $Id$
46 */
47
48
49
50 package org.jaxen.expr;
51
52 import java.io.Serializable;
53 import java.util.List;
54
55 import org.jaxen.Context;
56 import org.jaxen.JaxenException;
57
58
59 /**
60 * A wrapper around an XPath expression.
61 *
62 */
63 public interface XPathExpr extends Serializable
64 {
65
66 /**
67 * Returns the wrapped expression object.
68 *
69 * @return the wrapped Expr object
70 */
71 Expr getRootExpr();
72
73
74 /**
75 * Changes the wrapped expression object.
76 *
77 * @param rootExpr the new expression object to wrap
78 */
79 void setRootExpr(Expr rootExpr);
80
81 /**
82 * Returns a String containing the XPath expression.
83 *
84 * @return the text form of this XPath expression
85 */
86 String getText();
87
88 /**
89 * Simplifies the XPath expression. For example, the expression
90 * <code>//para[1 = 1]</code> could be simplified to
91 * <code>//para</code>. In practice, this is usually a noop.
92 * Jaxen does not currently perform any simplification.
93 */
94 void simplify();
95
96
97 /**
98 * Evaluates the expression and returns a list containing the resulting nodes,
99 * or a singleton list containing a <code>Double</code>, <code>String</code>,
100 * or <code>Boolean</code>.
101 *
102 * @param context the context in which to evaluate this expression
103 * @return a list
104 * @throws JaxenException if expression evaluation fails
105 */
106 List asList(Context context) throws JaxenException;
107
108 }