/**
* 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.brixcms.markup.transform;
import org.brixcms.markup.MarkupSource;
import org.brixcms.markup.MarkupSourceWrapper;
import org.brixcms.markup.tag.Item;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
/**
* Base class for {@link MarkupSource} transformers. This class allows to interact with the list of all {@link Item}s
* rather than with one item at a time.
*
* @author Matej Knopp
*/
public abstract class MarkupSourceTransformer extends MarkupSourceWrapper {
private List<Item> items = null;
private Iterator<Item> iterator = null;
public MarkupSourceTransformer(MarkupSource delegate) {
super(delegate);
}
@Override
public Item nextMarkupItem() {
if (items == null) {
List<Item> temp = new ArrayList<Item>();
Item i = getDelegate().nextMarkupItem();
while (i != null) {
temp.add(i);
i = getDelegate().nextMarkupItem();
}
items = transform(temp);
if (items == null) {
items = Collections.emptyList();
}
iterator = items.iterator();
}
if (iterator != null && iterator.hasNext()) {
return iterator.next();
} else {
return null;
}
}
/**
* Performs the actual transformation.
*
* @param originalItems
* @return
*/
protected abstract List<Item> transform(List<Item> originalItems);
}