stylesheetrenderer.java

structs源码

/*
 * $Id: StylesheetRenderer.java 471754 2006-11-06 14:55:09Z husted $
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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
 *
 *  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.apache.struts.faces.renderer;


import java.io.IOException;

import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;
import javax.faces.context.ResponseWriter;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;


/**
 * <p><code>Renderer</code> implementation for the <code>stylesheet</code> tag
 * from the <em>Struts-Faces Integration Library</em>.</p>
 *
 * @version $Rev: 471754 $ $Date: 2006-11-06 08:55:09 -0600 (Mon, 06 Nov 2006) $
 */

public class StylesheetRenderer extends AbstractRenderer {


    // -------------------------------------------------------- Static Variables


    /**
     * <p>The <code>Log</code> instance for this class.</p>
     */
    private static Log log = LogFactory.getLog(StylesheetRenderer.class);


    // ---------------------------------------------------------- Public Methods


    /**
     * <p>Render a relative HTML <code>&lt;link&gt;</code> element for a
     * <code>text/css</code> stylesheet at the specified context-relative
     * path.</p>
     *
     * @param context FacesContext for the request we are processing
     * @param component UIComponent to be rendered
     *
     * @exception IOException if an input/output error occurs while rendering
     * @exception NullPointerException if <code>context</code>
     *  or <code>component</code> is <code>null</code>
     */
    public void encodeEnd(FacesContext context, UIComponent component)
        throws IOException {

        if ((context == null) || (component == null)) {
            throw new NullPointerException();
        }

        ResponseWriter writer = context.getResponseWriter();
        writer.startElement("link", component);
        writer.writeAttribute("rel", "stylesheet", null);
        writer.writeAttribute("type", "text/css", null);
        writer.writeURIAttribute
            ("href",
             context.getExternalContext().getRequestContextPath() +
             (String) component.getAttributes().get("path"), "path");
        writer.endElement("link");
        writer.writeText("\n", null);

    }



    // ------------------------------------------------------- Protected Methods


}