HeadRenderer.java

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2010 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * https://glassfish.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
 * exception as provided by Oracle in the GPL Version 2 section of the License
 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
 * "Portions Copyright [year] [name of copyright owner]"
 *
 * Contributor(s):
 * If you wish your version of this file to be governed by only the CDDL or
 * only the GPL Version 2, indicate your decision by adding "[Contributor]
 * elects to include this software in this distribution under the [CDDL or GPL
 * Version 2] license."  If you don't indicate a single choice of license, a
 * recipient has the option to distribute your version of this file under
 * either the CDDL, the GPL Version 2 or to extend the choice of license to
 * its licensees as provided above.  However, if you add GPL Version 2 code
 * and therefore, elected the GPL Version 2 license, then the option applies
 * only if the new code is made subject to such option by the copyright
 * holder.
 */

package com.sun.faces.renderkit.html_basic;

import com.sun.faces.config.FaceletsConfiguration;
import com.sun.faces.config.WebConfiguration;
import com.sun.faces.renderkit.RenderKitUtils;
import com.sun.faces.renderkit.Attribute;
import com.sun.faces.renderkit.AttributeManager;

import java.io.IOException;

import javax.faces.component.UIComponent;
import javax.faces.component.UIViewRoot;
import javax.faces.context.FacesContext;
import javax.faces.context.ResponseWriter;
import javax.faces.render.Renderer;

/**
 * /**
 * <p>This <code>Renderer</code> is responsible for rendering
 * the standard HTML head elements as well as rendering any resources
 * that should be output before the <code>head</code> tag is closed.</p>
 */
public class HeadRenderer extends Renderer {

    private static final Attribute[] HEAD_ATTRIBUTES =
          AttributeManager.getAttributes(AttributeManager.Key.OUTPUTHEAD);

    @Override
    public void decode(FacesContext context, UIComponent component) {
        // no-op
    }

    @Override
    public void encodeBegin(FacesContext context, UIComponent component)
          throws IOException {
        ResponseWriter writer = context.getResponseWriter();
        writer.startElement("head", component);
        RenderKitUtils.renderPassThruAttributes(context,
                                                writer,
                                                component,
                                                HEAD_ATTRIBUTES);
        WebConfiguration webConfig = WebConfiguration.getInstance(context.getExternalContext());
        FaceletsConfiguration faceletsConfig = webConfig.getFaceletsConfiguration();
        if (faceletsConfig.isOutputHtml5Doctype(context.getViewRoot().getViewId())) {
            String clientId = component.getClientId(context);
            writer.writeAttribute("id", clientId, "clientId");
        }
    }

    @Override
    public void encodeChildren(FacesContext context, UIComponent component)
          throws IOException {
        // no-op
    }

    @Override
    public void encodeEnd(FacesContext context, UIComponent component)
          throws IOException {
        ResponseWriter writer = context.getResponseWriter();
        encodeHeadResources(context);
        writer.endElement("head");
    }


    // --------------------------------------------------------- Private Methods


    private void encodeHeadResources(FacesContext context)
    throws IOException {

        UIViewRoot viewRoot = context.getViewRoot();
        for (UIComponent resource : viewRoot.getComponentResources(context, "head")) {
            resource.encodeAll(context);
        }

    }
    
}