/*
* Copyright 1999-2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.cocoon.transformation.helpers;
import java.util.HashMap;
import java.util.Map;
import org.apache.avalon.framework.configuration.Configuration;
import org.apache.avalon.framework.configuration.ConfigurationException;
import org.apache.avalon.framework.configuration.DefaultConfigurationSerializer;
import org.apache.avalon.framework.parameters.Parameters;
import org.xml.sax.SAXException;
/**
* An Avalon <code>Configuration</code> factory that allows {variables} to be
* replaced with values from a lookup table.
*
* @author <a href="jefft@apache.org">Jeff Turner</a>
* @version CVS $Id: VariableConfiguration.java 30932 2004-07-29 17:35:38Z vgritsenko $
*/
public class VariableConfiguration {
public static final String UNSET_VAR="unset";
private Configuration conf;
private Map vars = new HashMap();
/** Constructor.
* @param conf Template Configuration with {variables} to marking where
* values should be interpolated. May be <code>null</code>.
*/
public VariableConfiguration(Configuration conf) {
this.conf = conf;
}
/** Add a name-value pair.
*/
public void addVariable(String name, String value) {
vars.put(name, value);
}
/** Add a set of name-value pairs.
*/
public void addVariables(Parameters params) {
String[] names = params.getNames();
for (int i=0; i<names.length; i++) {
String paramVal = params.getParameter(names[i], null);
if (paramVal != null) {
vars.put(names[i], paramVal);
}
}
}
/**
* Get a generated Configuration with interpolated variable values.
* @return The Configuration passed in the constructor, with {variable}
* tokens in attributes and element bodies replaced with values (if
* specified), or <code>null</code>.
*/
public Configuration getConfiguration() throws SAXException, ConfigurationException {
if (this.conf == null) return null;
InterpolatingConfigurationHandler handler = new InterpolatingConfigurationHandler(this.vars, this.conf.getLocation());
DefaultConfigurationSerializer ser = new DefaultConfigurationSerializer();
ser.serialize(handler, this.conf);
return handler.getConfiguration();
}
}