/*
============================================================================
The Apache Software License, Version 1.1
============================================================================
Copyright (C) 1999-2002 The Apache Software Foundation. All rights reserved.
Redistribution and use in source and binary forms, with or without modifica-
tion, are permitted provided that the following conditions are met:
1. Redistributions of source code must retain the above copyright notice,
this list of conditions and the following disclaimer.
2. 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.
3. The end-user documentation included with the redistribution, if any, must
include the following acknowledgment: "This product includes software
developed by the Apache Software Foundation (http://www.apache.org/)."
Alternately, this acknowledgment may appear in the software itself, if
and wherever such third-party acknowledgments normally appear.
4. The names "Apache Cocoon" and "Apache Software Foundation" must not be
used to endorse or promote products derived from this software without
prior written permission. For written permission, please contact
apache@apache.org.
5. Products derived from this software may not be called "Apache", nor may
"Apache" appear in their name, without prior written permission of the
Apache Software Foundation.
THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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
APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLU-
DING, 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 Apache Software Foundation and was originally created by
Stefano Mazzocchi <stefano@apache.org>. For more information on the Apache
Software Foundation, please see <http://www.apache.org/>.
*/
package org.apache.cocoon.matching;
import org.apache.avalon.framework.parameters.Parameters;
import org.apache.avalon.framework.thread.ThreadSafe;
import org.apache.cocoon.environment.ObjectModelHelper;
import org.apache.cocoon.sitemap.PatternException;
import org.apache.regexp.RE;
import org.apache.regexp.RECompiler;
import org.apache.regexp.REProgram;
import org.apache.regexp.RESyntaxException;
import java.util.HashMap;
import java.util.Map;
/**
* Base class for all matchers using a regular expression pattern.
*
* @author <a href="mailto:Giacomo.Pati@pwr.ch">Giacomo Pati</a>
* @author <a href="mailto:bloritsch@apache.org">Berin Loritsch</a>
* @authos <a href="mailto:sylvain@apache.org">Sylvain Wallez</a>
* @version CVS $Id: AbstractRegexpMatcher.java,v 1.5.2.2 2002/05/01 10:54:31 haul Exp $
*/
public abstract class AbstractRegexpMatcher extends AbstractPreparableMatcher implements ThreadSafe {
/**
* Compile the pattern in a <code>org.apache.regexp.REProgram</code>.
*/
public Object preparePattern(String pattern) throws PatternException {
if (pattern == null)
{
throw new PatternException("null passed as a pattern", null);
}
if (pattern.length() == 0)
{
pattern = "^$";
if (getLogger().isWarnEnabled()) {
getLogger().warn("The empty pattern string was rewritten to '^$'"
+ " to match for empty strings. If you intended"
+ " to match all strings, please change your"
+ " pattern to '.*'");
}
}
try {
RECompiler compiler = new RECompiler();
REProgram program = compiler.compile(pattern);
return program;
} catch (RESyntaxException rse) {
getLogger().debug("Failed to compile the pattern '" + pattern + "'", rse);
throw new PatternException(rse.getMessage(), rse);
}
}
/**
* Match the prepared pattern against the value returned by {@link #getMatchString(Map, Parameters)}.
*/
public Map preparedMatch(Object preparedPattern, Map objectModel, Parameters parameters) {
RE re = new RE((REProgram)preparedPattern);
String match = getMatchString(objectModel, parameters);
if (match == null)
return null;
if(re.match(match)) {
/* Handle parenthesised subexpressions. XXX: could be faster if we count
* parens *outside* the generated code.
* Note: *ONE* based, not zero, zero contains complete match
*/
int parenCount = re.getParenCount();
Map map = new HashMap();
for (int paren = 0; paren <= parenCount; paren++) {
map.put(Integer.toString(paren), re.getParen(paren));
}
return map;
}
return null;
}
/**
* Get the string to test against the regular expression. To be defined
* by concrete subclasses.
*/
protected abstract String getMatchString(Map objectModel, Parameters parameters);
}