Source code: ognl/Node.java
1 //--------------------------------------------------------------------------
2 // Copyright (c) 1998-2004, Drew Davidson and Luke Blanshard
3 // All rights reserved.
4 //
5 // Redistribution and use in source and binary forms, with or without
6 // modification, are permitted provided that the following conditions are
7 // met:
8 //
9 // Redistributions of source code must retain the above copyright notice,
10 // this list of conditions and the following disclaimer.
11 // Redistributions in binary form must reproduce the above copyright
12 // notice, this list of conditions and the following disclaimer in the
13 // documentation and/or other materials provided with the distribution.
14 // Neither the name of the Drew Davidson nor the names of its contributors
15 // may be used to endorse or promote products derived from this software
16 // without specific prior written permission.
17 //
18 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21 // FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22 // COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
23 // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
24 // BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
25 // OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
26 // AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
27 // OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
28 // THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
29 // DAMAGE.
30 //--------------------------------------------------------------------------
31 package ognl;
32
33 /**
34 JJTree interface for AST nodes, as modified to handle the OGNL operations getValue and
35 setValue. JJTree's original comment:
36
37 All AST nodes must implement this interface. It provides basic
38 machinery for constructing the parent and child relationships
39 between nodes.
40
41 @author Luke Blanshard (blanshlu@netscape.net)
42 @author Drew Davidson (drew@ognl.org)
43 */
44 public interface Node
45 {
46
47 /** This method is called after the node has been made the current
48 node. It indicates that child nodes can now be added to it. */
49 public void jjtOpen();
50
51 /** This method is called after all the child nodes have been
52 added. */
53 public void jjtClose();
54
55 /** This pair of methods are used to inform the node of its
56 parent. */
57 public void jjtSetParent(Node n);
58 public Node jjtGetParent();
59
60 /** This method tells the node to add its argument to the node's
61 list of children. */
62 public void jjtAddChild(Node n, int i);
63
64 /** This method returns a child node. The children are numbered
65 from zero, left to right. */
66 public Node jjtGetChild(int i);
67
68 /** Return the number of children the node has. */
69 public int jjtGetNumChildren();
70
71
72 // OGNL additions to Node:
73
74 /**
75 * Extracts the value from the given source object that is appropriate for this node
76 * within the given context.
77 */
78 public Object getValue( OgnlContext context, Object source ) throws OgnlException;
79
80 /**
81 * Sets the given value in the given target as appropriate for this node within the
82 * given context.
83 */
84 public void setValue( OgnlContext context, Object target, Object value ) throws OgnlException;
85 }