/*
* #!
* Ontopia Navigator
* #-
* Copyright (C) 2001 - 2013 The Ontopia Project
* #-
* 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 net.ontopia.topicmaps.nav2.taglibs.TMvalue;
import java.util.Iterator;
import java.util.Collection;
import java.util.Collections;
import java.util.ArrayList;
import javax.servlet.jsp.JspTagException;
import net.ontopia.topicmaps.core.ReifiableIF;
import net.ontopia.topicmaps.core.TopicIF;
import net.ontopia.topicmaps.core.TMObjectIF;
import net.ontopia.topicmaps.nav2.taglibs.value.BaseValueProducingAndAcceptingTag;
/**
* INTERNAL: Finds the reifying topic of each topic map object in a
* collection.
*/
public class ReifierTag extends BaseValueProducingAndAcceptingTag {
public Collection process(Collection tmObjects) throws JspTagException {
// Find all reifying topics of all topic map objects in collection
if (tmObjects == null || tmObjects.isEmpty())
return Collections.EMPTY_SET;
else {
ArrayList reifyingTopics = new ArrayList();
Iterator iter = tmObjects.iterator();
TopicIF reifyingTopic;
// Loop over the topic map objects
while (iter.hasNext()) {
// Get the topic that reifies the given topic map object
reifyingTopic = ((ReifiableIF)iter.next()).getReifier();
// If a topic was found add it to the result list.
if (reifyingTopic != null)
reifyingTopics.add(reifyingTopic);
}
// Return all reifiying topics found.
return reifyingTopics;
}
}
}