/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.shindig.gadgets.templates.tags;
import org.apache.shindig.gadgets.templates.TemplateProcessor;
import org.apache.shindig.gadgets.templates.ElementELResolver.ElementWrapper;
import org.w3c.dom.DocumentFragment;
import org.w3c.dom.Element;
import org.w3c.dom.NamedNodeMap;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import java.util.List;
import java.util.Map;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
/**
* TagHandler implemented by an declarative XML definition.
*/
public class TemplateBasedTagHandler extends AbstractTagHandler {
private final Element templateDefinition;
public TemplateBasedTagHandler(Element templateDefinition, String namespaceUri, String tagName) {
super(namespaceUri, tagName);
this.templateDefinition = templateDefinition;
}
public void process(Node result, Element tagInstance, TemplateProcessor processor) {
// Process the children of the tag
DocumentFragment processedContent = processChildren(tagInstance, processor);
// Save the old values of "My", "Cur", and the template root element,
// and update each
Map<String, Object> oldMy = processor.getTemplateContext().setMy(
computeMy(tagInstance, processedContent, processor));
Object oldCur = processor.getTemplateContext().setCur(null);
Node oldTemplateRoot = processor.getTemplateContext().setTemplateRoot(processedContent);
processTemplate(result, tagInstance, processor);
// And restore the template context
processor.getTemplateContext().setMy(oldMy);
processor.getTemplateContext().setCur(oldCur);
processor.getTemplateContext().setTemplateRoot(oldTemplateRoot);
}
/** Process the template content in the new EL state */
protected void processTemplate(Node result, Element tagInstance, TemplateProcessor processor) {
synchronized (result) {
processor.processChildNodes(result, templateDefinition);
}
}
/**
* Compute the value of ${My} for this tag execution.
*/
protected Map<String, Object> computeMy(Element tagInstance, Node processedContent,
TemplateProcessor processor) {
Map<String, Object> myMap = Maps.newHashMap();
Node clonedSource;
synchronized (processedContent) {
clonedSource = processedContent.cloneNode(true);
}
int children = clonedSource.getChildNodes().getLength();
Node childNode = clonedSource.getFirstChild();
while(childNode != null) {
if (childNode instanceof Element) {
Element el = (Element) childNode;
String name = el.getLocalName();
// TODO: why??? There should always be a local name.
if (name == null) {
name = el.getNodeName();
}
ElementWrapper wrapper = new ElementWrapper(el);
Object previous = myMap.get(name);
if (previous == null) {
myMap.put(name, wrapper);
} else if (previous instanceof ElementWrapper) {
List<ElementWrapper> bucket = Lists.newArrayListWithCapacity(children);
bucket.add((ElementWrapper) previous);
bucket.add(wrapper);
myMap.put(name, bucket);
} else {
// Must be a List<ElementWrapper>
@SuppressWarnings("unchecked")
List<ElementWrapper> bucket = (List<ElementWrapper>) previous;
bucket.add(wrapper);
}
}
childNode = childNode.getNextSibling();
}
NamedNodeMap atts = tagInstance.getAttributes();
for (int i = 0; i < atts.getLength(); i++) {
String name = atts.item(i).getNodeName();
// Overwrite any pre-existing values, as attributes take
// precedence over elements. This is wasteful if there are attributes
// and elements with the same name, but that should be very rare
myMap.put(name, getValueFromTag(tagInstance, name, processor, Object.class));
}
return myMap;
}
}