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Google App Engine compliant variation of FreeMarker.
FreeMarker is a "template engine"; a generic tool to generate text output based on templates.
/*
* Copyright 2014 Attila Szegedi, Daniel Dekany, Jonathan Revusky
*
* 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 freemarker.ext.beans;
import java.util.Iterator;
import java.util.NoSuchElementException;
import freemarker.template.TemplateCollectionModel;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;
import freemarker.template.TemplateModelIterator;
/**
* A class that adds {@link TemplateModelIterator} functionality to the
* {@link Iterator} interface implementers.
*
* It differs from the {@link freemarker.template.SimpleCollection} in that
* it inherits from {@link BeanModel}, and therefore you can call methods on
* it directly, even to the effect of calling iterator.remove() in
* the template.
Using the model as a collection model is NOT
* thread-safe, as iterators are inherently not thread-safe.
* Further, you can iterate over it only once. Attempts to call the
* {@link #iterator()} method after it was already driven to the end once will
* throw an exception.
*/
public class IteratorModel
extends
BeanModel
implements
TemplateModelIterator,
TemplateCollectionModel
{
private boolean accessed = false;
/**
* Creates a new model that wraps the specified iterator object.
* @param iterator the iterator object to wrap into a model.
* @param wrapper the {@link BeansWrapper} associated with this model.
* Every model has to have an associated {@link BeansWrapper} instance. The
* model gains many attributes from its wrapper, including the caching
* behavior, method exposure level, method-over-item shadowing policy etc.
*/
public IteratorModel(Iterator iterator, BeansWrapper wrapper)
{
super(iterator, wrapper);
}
/**
* This allows the iterator to be used in a <#list> block.
* @return "this"
*/
public TemplateModelIterator iterator() throws TemplateModelException
{
synchronized(this) {
if(accessed) {
throw new TemplateModelException(
"This collection is stateful and can not be iterated over the" +
" second time.");
}
accessed = true;
}
return this;
}
/**
* Calls underlying {@link Iterator#hasNext()}.
*/
public boolean hasNext() {
return ((Iterator)object).hasNext();
}
/**
* Calls underlying {@link Iterator#next()} and wraps the result.
*/
public TemplateModel next()
throws
TemplateModelException
{
try {
return wrap(((Iterator)object).next());
}
catch(NoSuchElementException e) {
throw new TemplateModelException(
"No more elements in the iterator.", e);
}
}
/**
* Returns {@link Iterator#hasNext()}. Therefore, an
* iterator that has no more element evaluates to false, and an
* iterator that has further elements evaluates to true.
*/
public boolean getAsBoolean() {
return hasNext();
}
}