/*
* Copyright 2002,2004 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.commons.jelly.impl;
import java.util.Iterator;
import java.util.Map;
import org.apache.commons.jelly.DynaTag;
import org.apache.commons.jelly.JellyContext;
import org.apache.commons.jelly.JellyException;
import org.apache.commons.jelly.JellyTagException;
import org.apache.commons.jelly.Tag;
import org.apache.commons.jelly.TagLibrary;
import org.apache.commons.jelly.XMLOutput;
import org.apache.commons.jelly.expression.Expression;
import org.xml.sax.SAXException;
/**
* <p><code>StaticTagScript</code> is a script that evaluates a StaticTag, a piece of static XML
* though its attributes or element content may contain dynamic expressions.
* The first time this tag evaluates, it may have become a dynamic tag, so it will check that
* a new dynamic tag has not been generated.</p>
*
* @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
* @version $Revision: 1.8 $
*/
public class StaticTagScript extends TagScript {
public StaticTagScript() {
}
public StaticTagScript(TagFactory tagFactory) {
super(tagFactory);
}
// Script interface
//-------------------------------------------------------------------------
public void run(JellyContext context, XMLOutput output) throws JellyTagException {
try {
startNamespacePrefixes(output);
} catch (SAXException e) {
throw new JellyTagException("could not start namespace prefixes",e);
}
Tag tag = null;
try {
tag = getTag();
// lets see if we have a dynamic tag
if (tag instanceof StaticTag) {
tag = findDynamicTag(context, (StaticTag) tag);
}
setTag(tag);
} catch (JellyException e) {
throw new JellyTagException(e);
}
try {
if ( tag == null ) {
return;
}
tag.setContext(context);
DynaTag dynaTag = (DynaTag) tag;
// ### probably compiling this to 2 arrays might be quicker and smaller
for (Iterator iter = attributes.entrySet().iterator(); iter.hasNext();) {
Map.Entry entry = (Map.Entry) iter.next();
String name = (String) entry.getKey();
Expression expression = (Expression) entry.getValue();
Object value = null;
if ( Expression.class.isAssignableFrom( dynaTag.getAttributeType(name) ) ) {
value = expression;
} else {
value = expression.evaluate(context);
}
dynaTag.setAttribute(name, value);
}
tag.doTag(output);
}
catch (JellyTagException e) {
handleException(e);
}
catch (RuntimeException e) {
handleException(e);
}
try {
endNamespacePrefixes(output);
} catch (SAXException e) {
throw new JellyTagException("could not end namespace prefixes",e);
}
}
/**
* Attempts to find a dynamically created tag that has been created since this
* script was compiled
*/
protected Tag findDynamicTag(JellyContext context, StaticTag tag) throws JellyException {
// lets see if there's a tag library for this URI...
TagLibrary taglib = context.getTagLibrary( tag.getUri() );
if ( taglib != null ) {
Tag newTag = taglib.createTag( tag.getLocalName(), getSaxAttributes() );
if ( newTag != null ) {
newTag.setParent( tag.getParent() );
newTag.setBody( tag.getBody() );
return newTag;
}
}
return tag;
}
}