PortletSubscribeIdResolver.java

/**
 * Licensed to Apereo under one or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information regarding copyright ownership. Apereo
 * 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 the
 * following location:
 *
 * <p>http://www.apache.org/licenses/LICENSE-2.0
 *
 * <p>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.apereo.portal.layout;

import org.apache.commons.lang.StringUtils;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

/**
 * Returns the subscribe ID of a channel having the passed in functional name or null if it can't
 * find such a channel in the layout.
 */
public class PortletSubscribeIdResolver implements INodeIdResolver {
    private final String fname;

    /** @param fname Functional name of portlet whose subscribe id to search for. */
    public PortletSubscribeIdResolver(String fname) {
        this.fname = fname;
    }

    @Override
    public String traverseDocument(Document document) {
        final NodeList channels = document.getElementsByTagName("channel");
        for (int i = 0; i < channels.getLength(); i++) {
            final Element e = (Element) channels.item(i);
            if (fname.equals(e.getAttribute("fname"))) {
                String ID = e.getAttribute("ID");
                return StringUtils.isEmpty(ID) ? null : ID;
            }
        }
        return null;
    }
}