/*
* Copyright (c) 1998-2010 Caucho Technology -- all rights reserved
*
* This file is part of Resin(R) Open Source
*
* Each copy or derived work must preserve the copyright notice and this
* notice unmodified.
*
* Resin Open Source is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* Resin Open Source is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
* of NON-INFRINGEMENT. See the GNU General Public License for more
* details.
*
* You should have received a copy of the GNU General Public License
* along with Resin Open Source; if not, write to the
* Free SoftwareFoundation, Inc.
* 59 Temple Place, Suite 330
* Boston, MA 02111-1307 USA
*
* @author Scott Ferguson
*/
package com.caucho.xpath.expr;
import com.caucho.xml.NodeListImpl;
import com.caucho.xml.XmlUtil;
import com.caucho.xpath.Expr;
import com.caucho.xpath.ExprEnvironment;
import com.caucho.xpath.XPathException;
import com.caucho.xpath.pattern.*;
import org.w3c.dom.Node;
public class NodeSetExpr extends Expr {
private AbstractPattern _pattern;
NodeSetExpr(AbstractPattern pattern)
{
_pattern = pattern;
}
/**
* Creates an expr, handling some special cases.
*/
public static Expr create(AbstractPattern pattern)
{
if (pattern instanceof NodeTypePattern
&& pattern.getParent() instanceof FromSelf
&& pattern.toString().equals("."))
return new ObjectExpr(SELF, ".");
else if (pattern instanceof FromContext
&& ((FromContext) pattern).getCount() == 0
&& pattern.getParent() == null)
return new ObjectExpr(SELF, ".");
else if (pattern instanceof NodePattern
&& pattern.getParent() instanceof FromAttributes
&& pattern.getParent().getParent() instanceof FromContext
&& ((FromContext) pattern.getParent().getParent()).getCount() == 0)
return new ObjectExpr(ATTRIBUTE, ((NodePattern) pattern).getNodeName());
else
return new NodeSetExpr(pattern);
}
/**
* Returns the underlying pattern.
*/
public AbstractPattern getPattern()
{
return _pattern;
}
/**
* NodeSetExprs prefer to be node sets.
*/
public boolean isNodeSet()
{
return true;
}
/**
* Returns the value of the expression as a number.
*
* @param node the current node
* @param env the variable environment.
*/
public double evalNumber(Node node, ExprEnvironment env)
throws XPathException
{
Node value = _pattern.findAny(node, env);
if (value == null)
return Double.NaN;
String string = XmlUtil.textValue(value);
return stringToNumber(string);
}
/**
* Returns true if there are any patterns matching the pattern.
*
* @param node the current node
* @param env the variable environment.
*/
public boolean evalBoolean(Node node, ExprEnvironment env)
throws XPathException
{
return _pattern.findAny(node, env) != null;
}
/**
* Returns the value of the node set expression as a string.
* The value is the text value of the first node.
*
* @param node the current node
* @param env the variable environment
*
* @return the combined text value of the node.
*/
public String evalString(Node node, ExprEnvironment env)
throws XPathException
{
Node value = _pattern.findAny(node, env);
if (value == null)
return "";
else
return XmlUtil.textValue(value);
}
/**
* Evaluate a node-set object, returning an ArrayList of the node set.
*
* @param node the current node
* @param env the variable environment
*
* @return an array list of the nodes
*/
public Object evalObject(Node node, ExprEnvironment env)
throws XPathException
{
NodeListImpl list = new NodeListImpl();
NodeIterator iter = _pattern.select(node, env);
Node value = null;
while ((value = iter.nextNode()) != null)
list.add(value);
return list;
}
/**
* Evaluate a node-set object, returning an iterator of the node set.
*
* @param node the current node
* @param env the variable environment
*
* @return an iterator of the nodes
*/
public NodeIterator evalNodeSet(Node node, ExprEnvironment env)
throws XPathException
{
return _pattern.select(node, env);
}
/**
* Convert from an expression to a pattern.
*/
protected AbstractPattern toNodeList()
{
return _pattern;
}
public boolean equals(Object b)
{
if (! (b instanceof NodeSetExpr))
return false;
return _pattern.equals(((NodeSetExpr) b)._pattern);
}
public String toString()
{
return _pattern.toString();
}
}