001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.wicket.markup.html;
018
019import org.apache.wicket.Application;
020import org.apache.wicket.markup.head.HeaderItem;
021import org.apache.wicket.markup.head.IHeaderResponse;
022import org.apache.wicket.util.io.IClusterable;
023
024/**
025 * An interface to be implemented by application level listeners or other entities that wish to
026 * contribute to the header section of the page. Class {@link org.apache.wicket.Component} already
027 * implements it. <br/>
028 * Example: <br/>
029 * <br/>
030 * 
031 * <pre>
032 * class MyPanel extends Panel
033 * {
034 *      public MyPanel(String id)
035 *      {
036 *              super(id);
037 *      }
038 * 
039 *      public void renderHead(IHeaderResponse response)
040 *      {
041 *              response.render(JavaScriptHeaderItem.forScript(&quot;alert('page loaded!');&quot;));
042 *      }
043 * }
044 * </pre>
045 * 
046 * @see IHeaderResponse
047 * @see HeaderItem
048 * @see Application#getHeaderContributorListeners()
049 * 
050 * @author Juergen Donnerstag
051 * @author Matej Knopp
052 */
053public interface IHeaderContributor extends IClusterable
054{
055        /**
056         * Render to the web response whatever the component wants to contribute to the head section.
057         * 
058         * @param response
059         *            Response object
060         */
061        void renderHead(IHeaderResponse response);
062}