ognl.Node Maven / Gradle / Ivy
//--------------------------------------------------------------------------
// Copyright (c) 1998-2004, Drew Davidson and Luke Blanshard
// 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 Drew Davidson 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
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// 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.
//--------------------------------------------------------------------------
package ognl;
import ognl.enhance.ExpressionAccessor;
/**
JJTree interface for AST nodes, as modified to handle the OGNL operations getValue and
setValue. JJTree's original comment:
All AST nodes must implement this interface. It provides basic
machinery for constructing the parent and child relationships
between nodes.
@author Luke Blanshard ([email protected])
@author Drew Davidson ([email protected])
*/
public interface Node extends JavaSource
{
/** This method is called after the node has been made the current
node. It indicates that child nodes can now be added to it. */
public void jjtOpen();
/** This method is called after all the child nodes have been
added. */
public void jjtClose();
/** This pair of methods are used to inform the node of its
parent.
*
* @param n the Node to make the parent of this node.
*/
public void jjtSetParent(Node n);
public Node jjtGetParent();
/** This method tells the node to add its argument to the node's
list of children.
*
* @param n the Node to add as a child of this node.
* @param i the position at which to add the child node.
*/
public void jjtAddChild(Node n, int i);
/** This method returns a child node. The children are numbered
from zero, left to right.
*
* @param i the position from which to get the child node.
* @return the child Node at position i.
*/
public Node jjtGetChild(int i);
/** Return the number of children the node has.
*
* @return the number of children for this node.
*/
public int jjtGetNumChildren();
// OGNL additions to Node:
/**
* Extracts the value from the given source object that is appropriate for this node
* within the given context.
*
* @param context the OgnlContext within which to perform the operation.
* @param source the Object from which to get the value.
* @return the value from the source (as appropriate within the provided context).
* @throws OgnlException if the value get fails.
*/
public Object getValue( OgnlContext context, Object source ) throws OgnlException;
/**
* Sets the given value in the given target as appropriate for this node within the
* given context.
*
* @param context the OgnlContext within which to perform the operation.
* @param target the Object upon which to set the value.
* @param value the Object representing the value to apply to the target.
* @throws OgnlException if the value set fails.
*/
public void setValue( OgnlContext context, Object target, Object value ) throws OgnlException;
/**
* Gets the compiled bytecode enhanced expression accessor for getting/setting values.
*
* @return The accessor for this node, or null if none has been compiled for it.
*/
ExpressionAccessor getAccessor();
/**
* Sets a new compiled accessor for this node expression.
*
* @param accessor The compiled representation of this node.
*/
void setAccessor(ExpressionAccessor accessor);
}