/**********************************************************************************
* $URL: https://source.sakaiproject.org/svn/jsf/tags/sakai_2-3-1/widgets/src/java/org/sakaiproject/jsf/renderer/StylesheetRenderer.java $
* $Id: StylesheetRenderer.java 9278 2006-05-10 23:29:21Z ray@media.berkeley.edu $
***********************************************************************************
*
* Copyright (c) 2003, 2004 The Sakai Foundation.
*
* Licensed under the Educational Community License, Version 1.0 (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.opensource.org/licenses/ecl1.php
*
* 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.sakaiproject.jsf.renderer;

import java.io.IOException;
import javax.faces.component.UIComponent;
import javax.faces.component.UIOutput;
import javax.faces.context.FacesContext;
import javax.faces.context.ResponseWriter;
import javax.faces.render.Renderer;

import org.sakaiproject.jsf.util.RendererUtil;

/**
 * <p>Description: </p>
 * <p>Render a stylesheet link for the value of our component's
 * <code>path</code> attribute, prefixed by the context path of this
 * web application.</p>
 * <p>  Based on example code by Sun Microsystems. </p>
 * <p>Copyright: Copyright (c) 2004</p>
 * <p>Organization: Sakai Project</p>
 * @author Ed Smiley
 * @version $Id: StylesheetRenderer.java 9278 2006-05-10 23:29:21Z ray@media.berkeley.edu $
 */

public class StylesheetRenderer extends Renderer
{

  public boolean supportsComponentType(UIComponent component)
  {
    return (component instanceof UIOutput);
  }

  public void decode(FacesContext context, UIComponent component)
  {
  }

  public void encodeBegin(FacesContext context, UIComponent component)
    throws IOException
  {
    ;
  }

  public void encodeChildren(FacesContext context, UIComponent component)
    throws IOException
  {
    ;
  }

  /**
   * <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
   *
     * @throws IOException          if an input/output error occurs while rendering
   * @throws NullPointerException if <code>context</code>
   *                              or <code>component</code> is null
   */
  public void encodeEnd(FacesContext context, UIComponent component)
    throws IOException
  {

    if (!component.isRendered())
    {
      return;
     }

    ResponseWriter writer = context.getResponseWriter();

    String contextPath = (String)
      RendererUtil.getAttribute(context, component, "contextBase");
    if (contextPath==null || contextPath=="")
    {
      contextPath = context.getExternalContext().getRequestContextPath();
    }

    writer.write("<link rel=\"stylesheet\" type=\"text/css\" href=\"");

    writer.write(contextPath);
    writer.write( (String) RendererUtil.getAttribute(context, component, "path"));
    writer.write("\"/>");
  }

}
