/*
* $Header: /home/cvs/jakarta-commons-sandbox/jelly/src/java/org/apache/commons/jelly/tags/define/DynamicTag.java,v 1.7 2002/05/17 15:18:12 jstrachan Exp $
* $Revision: 1.7 $
* $Date: 2002/05/17 15:18:12 $
*
* ====================================================================
*
* 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
* modification, 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 acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Commons", 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 names without prior written
* permission of the Apache Group.
*
* 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 (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 Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*
* $Id: DynamicTag.java,v 1.7 2002/05/17 15:18:12 jstrachan Exp $
*/
package org.apache.commons.jelly.tags.betwixt;
import org.apache.commons.beanutils.Converter;
import org.apache.commons.beanutils.ConvertUtils;
import org.apache.commons.beanutils.ConversionException;
import org.apache.commons.betwixt.XMLIntrospector;
import org.apache.commons.betwixt.strategy.CapitalizeNameMapper;
import org.apache.commons.betwixt.strategy.DecapitalizeNameMapper;
import org.apache.commons.betwixt.strategy.HyphenatedNameMapper;
import org.apache.commons.betwixt.strategy.NameMapper;
import org.apache.commons.jelly.JellyException;
import org.apache.commons.jelly.MissingAttributeException;
import org.apache.commons.jelly.TagSupport;
import org.apache.commons.jelly.XMLOutput;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Creates a Betwixt XMLIntrospector instance that can be used by the other Betwixt tags.</p>
*
* @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
* @version $Revision: 1.7 $
*/
public class IntrospectorTag extends TagSupport {
/** The Log to which logging calls will be made. */
private static final Log log = LogFactory.getLog(IntrospectorTag.class);
private XMLIntrospector introspector;
private String var;
static {
// register converters to standard Strategies
ConvertUtils.register(
new Converter() {
public Object convert(Class type, Object value) {
if ( value instanceof String ) {
return createNameMapper((String) value);
}
else if ( value == null ) {
return null;
}
else {
throw new ConversionException(
"Don't know how to convert: " + value
+ " of type: " + value.getClass().getName()
+ " into a NameMapper"
);
}
}
},
NameMapper.class
);
}
public IntrospectorTag() {
}
// Tag interface
//-------------------------------------------------------------------------
public void doTag(final XMLOutput output) throws Exception {
if ( var == null ) {
throw new MissingAttributeException( "var" );
}
invokeBody(output);
XMLIntrospector introspector = getIntrospector();
context.setVariable( var, introspector );
// now lets clear this introspector so that its recreated again next time
this.introspector = null;
}
// Properties
//-------------------------------------------------------------------------
/**
* @return the current XMLIntrospector, lazily creating one if required
*/
public XMLIntrospector getIntrospector() {
if ( introspector == null ) {
introspector = createIntrospector();
}
return introspector;
}
/**
* Sets whether attributes or elements should be used for primitive types.
* The default is false.
*/
public void setAttributesForPrimitives(boolean attributesForPrimitives) {
getIntrospector().setAttributesForPrimitives(attributesForPrimitives);
}
/**
* Sets the name mapper used for element names.
* You can also use the Strings 'lowercase', 'uppercase' or 'hyphenated'
* as aliases to the common name mapping strategies or specify a class name String.
*/
public void setElementNameMapper(NameMapper nameMapper) {
getIntrospector().setElementNameMapper(nameMapper);
}
/**
* Sets the name mapper used for attribute names.
* You can also use the Strings 'lowercase', 'uppercase' or 'hyphenated'
* as aliases to the common name mapping strategies or specify a class name String.
*/
public void setAttributeNameMapper(NameMapper nameMapper) {
getIntrospector().setAttributeNameMapper(nameMapper);
}
/**
* Sets the variable name to output the new XMLIntrospector to.
* If this attribute is not specified then this tag must be nested
* inside an <parse> or <output> tag
*/
public void setVar(String var) {
this.var = var;
}
// Implementation methods
//-------------------------------------------------------------------------
/**
* Static helper method which will convert the given string into
* standard named strategies such as 'lowercase', 'uppercase' or 'hyphenated'
* or use the name as a class name and create a new instance.
*/
protected static NameMapper createNameMapper(String name) {
if ( name.equalsIgnoreCase( "lowercase" ) ) {
return new DecapitalizeNameMapper();
}
else if ( name.equalsIgnoreCase( "uppercase" ) ) {
return new CapitalizeNameMapper();
}
else if ( name.equalsIgnoreCase( "hyphenated" ) ) {
return new HyphenatedNameMapper();
}
else {
// lets try load the class of this name
Class theClass = null;
try {
theClass = Thread.currentThread().getContextClassLoader().loadClass( name );
}
catch (Exception e) {
throw new ConversionException( "Could not load class called: " + name, e );
}
Object object = null;
try {
object = theClass.newInstance();
}
catch (Exception e) {
throw new ConversionException( "Could not instantiate an instance of: " + name, e );
}
if ( object instanceof NameMapper ) {
return (NameMapper) object;
}
if ( object == null ) {
throw new ConversionException( "No NameMapper created for type: " + name );
}
else {
throw new ConversionException(
"Created object: " + object
+ " is not a NameMapper! Its type is: " + object.getClass().getName()
);
}
}
}
/**
* Factory method to create a new XMLIntrospector
*/
protected XMLIntrospector createIntrospector() {
return new XMLIntrospector();
}
}