/*
* $Header: /home/projects/jaxen/scm/jaxen/src/java/main/org/jaxen/pattern/PatternHandler.java,v 1.8 2006/02/05 21:47:42 elharo Exp $
* $Revision: 1.8 $
* $Date: 2006/02/05 21:47:42 $
*
* ====================================================================
*
* Copyright 2000-2002 bob mcwhirter & James Strachan.
* 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 Jaxen Project 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 COPYRIGHT OWNER
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 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.
*
* ====================================================================
* This software consists of voluntary contributions made by many
* individuals on behalf of the Jaxen Project and was originally
* created by bob mcwhirter <bob@werken.com> and
* James Strachan <jstrachan@apache.org>. For more information on the
* Jaxen Project, please see <http://www.jaxen.org/>.
*
* $Id: PatternHandler.java,v 1.8 2006/02/05 21:47:42 elharo Exp $
*/
package org.orbeon.jaxen.pattern;
import org.orbeon.jaxen.JaxenException;
import org.orbeon.jaxen.JaxenHandler;
import org.orbeon.jaxen.expr.Expr;
import org.orbeon.jaxen.expr.FilterExpr;
import org.orbeon.jaxen.saxpath.Axis;
import java.util.LinkedList;
/** SAXPath <code>XPathHandler</code> implementation capable
* of building Jaxen expression trees which can walk various
* different object models.
*
* @author bob mcwhirter (bob@werken.com)
*/
public class PatternHandler extends JaxenHandler
{
private Pattern pattern;
public PatternHandler()
{
}
/** Retrieve the simplified Jaxen Pattern expression tree.
*
* <p>
* This method is only valid once <code>XPathReader.parse(...)</code>
* successfully returned.
* </p>
*
* @return The Pattern expression tree.
*/
public Pattern getPattern()
{
return getPattern( true );
}
/** Retrieve the Jaxen Pattern expression tree, optionally
* simplified.
*
* <p>
* This method is only valid once <code>XPathReader.parse(...)</code>
* successfully returned.
* </p>
*
* @param shouldSimplify ????
*
* @return The Pattern expression tree.
*/
public Pattern getPattern(boolean shouldSimplify)
{
if ( shouldSimplify && ! this.simplified )
{
//System.err.println("simplifying....");
this.pattern.simplify();
this.simplified = true;
}
return this.pattern;
}
public void endXPath()
{
this.pattern = (Pattern) pop();
System.out.println( "stack is: " + stack );
popFrame();
}
public void endPathExpr()
{
//System.err.println("endPathExpr()");
// PathExpr ::= LocationPath
// | FilterExpr
// | FilterExpr / RelativeLocationPath
// | FilterExpr // RelativeLocationPath
//
// If the current stack-frame has two items, it's a
// FilterExpr and a LocationPath (of some flavor).
//
// If the current stack-frame has one item, it's simply
// a FilterExpr, and more than like boils down to a
// primary expr of some flavor. But that's for another
// method...
LinkedList frame = popFrame();
System.out.println( "endPathExpr(): " + frame );
push( frame.removeFirst() );
/*
LocationPathPattern locationPath = new LocationPathPattern();
push( locationPath );
while (! frame.isEmpty() )
{
Object filter = frame.removeLast();
if ( filter instanceof NodeTest )
{
locationPath.setNodeTest( (NodeTest) filter );
}
else if ( filter instanceof FilterExpr )
{
locationPath.addFilter( (FilterExpr) filter );
}
else if ( filter instanceof LocationPathPattern )
{
LocationPathPattern parent = (LocationPathPattern) filter;
locationPath.setParentPattern( parent );
locationPath = parent;
}
else if ( filter != null )
{
throw new JaxenException( "Unknown filter: " + filter );
}
}
*/
}
public void startAbsoluteLocationPath()
{
//System.err.println("startAbsoluteLocationPath()");
pushFrame();
push( createAbsoluteLocationPath() );
}
public void endAbsoluteLocationPath() throws JaxenException
{
//System.err.println("endAbsoluteLocationPath()");
endLocationPath();
}
public void startRelativeLocationPath()
{
//System.err.println("startRelativeLocationPath()");
pushFrame();
push( createRelativeLocationPath() );
}
public void endRelativeLocationPath() throws JaxenException
{
//System.err.println("endRelativeLocationPath()");
endLocationPath();
}
protected void endLocationPath() throws JaxenException
{
// start at the back, its the main pattern then add everything else as
LinkedList list = popFrame();
System.out.println( "endLocationPath: " + list );
LocationPathPattern locationPath = (LocationPathPattern) list.removeFirst();
push( locationPath );
boolean doneNodeTest = false;
while ( ! list.isEmpty() )
{
Object filter = list.removeFirst();
if ( filter instanceof NodeTest )
{
if ( doneNodeTest )
{
LocationPathPattern parent = new LocationPathPattern( (NodeTest) filter );
locationPath.setParentPattern( parent );
locationPath = parent;
doneNodeTest = false;
}
else
{
locationPath.setNodeTest( (NodeTest) filter );
}
}
else if ( filter instanceof FilterExpr )
{
locationPath.addFilter( (FilterExpr) filter );
}
else if ( filter instanceof LocationPathPattern )
{
LocationPathPattern parent = (LocationPathPattern) filter;
locationPath.setParentPattern( parent );
locationPath = parent;
doneNodeTest = false;
}
}
}
public void startNameStep(int axis,
String prefix,
String localName)
{
//System.err.println("startNameStep(" + axis + ", " + prefix + ", " + localName + ")");
pushFrame();
short nodeType = Pattern.ELEMENT_NODE;
switch ( axis )
{
case Axis.ATTRIBUTE:
nodeType = Pattern.ATTRIBUTE_NODE;
break;
case Axis.NAMESPACE:
nodeType = Pattern.NAMESPACE_NODE;
break;
}
if ( prefix != null && prefix.length() > 0 && ! prefix.equals( "*" ) )
{
push( new NamespaceTest( prefix, nodeType ) );
}
if ( localName != null && localName.length() > 0 && ! localName.equals( "*" ) )
{
push( new NameTest( localName, nodeType ) );
}
}
public void startTextNodeStep(int axis)
{
//System.err.println("startTextNodeStep()");
pushFrame();
push( new NodeTypeTest( Pattern.TEXT_NODE ) );
}
public void startCommentNodeStep(int axis)
{
//System.err.println("startCommentNodeStep()");
pushFrame();
push( new NodeTypeTest( Pattern.COMMENT_NODE ) );
}
public void startAllNodeStep(int axis)
{
//System.err.println("startAllNodeStep()");
pushFrame();
push( AnyNodeTest.getInstance() );
}
public void startProcessingInstructionNodeStep(int axis,
String name)
{
//System.err.println("startProcessingInstructionStep()");
pushFrame();
// XXXX: should we throw an exception if name is present?
push( new NodeTypeTest( Pattern.PROCESSING_INSTRUCTION_NODE ) );
}
protected void endStep()
{
LinkedList list = popFrame();
if ( ! list.isEmpty() )
{
push( list.removeFirst() );
if ( ! list.isEmpty() )
{
System.out.println( "List should now be empty!" + list );
}
}
}
public void startUnionExpr()
{
//System.err.println("startUnionExpr()");
}
public void endUnionExpr(boolean create) throws JaxenException
{
//System.err.println("endUnionExpr()");
if ( create )
{
//System.err.println("makeUnionExpr");
Expr rhs = (Expr) pop();
Expr lhs = (Expr) pop();
push( getXPathFactory().createUnionExpr( lhs,
rhs ) );
}
}
protected Pattern createAbsoluteLocationPath()
{
return new LocationPathPattern( NodeTypeTest.DOCUMENT_TEST );
}
protected Pattern createRelativeLocationPath()
{
return new LocationPathPattern();
}
}